ABSTRACT. India is making rapid strides in deployment of solar power generation capacity. Most of the capacity addition however is with solar photovoltaic technology. There is a general perception that solar thermal plants would be costlier than solar PV plants. The project costs and results of competitive bidding actually support such a view. This needs a deeper scrutiny. There may actually be a significant advantage in using solar thermal technology for establishing large capacity plants. The presentation will discuss this aspect in some detail. 

ABSTRACT. Over the years, renewable energy seems to have become synonymous with electrical power in India by default, either by public speeches of bureaucrats and policy makers or by an overt emphasis on power generation. Even the definition of Renewable Energy Certificate as 1 MWh shows a clear bias for power generation. Also, solar seems to have become synonymous with photovoltaic systems in recent years. The Ministry of New and Renewable Energy (MNRE) does have many programs to its credit, but the emphasis on power is unmissable. While electrical power is an important area and PV is emerging rapidly as an alternative, governments need to develop a holistic approach in which resource distribution, consumer base, product viability, application potential etc have to be given due importance. This presentation attempts to discuss some issues and challenges of solar thermal power and argues that there is a need for re-formulation of policies for encouraging development and promotion of some “low hanging fruits” in solar thermal applications to promote a holistic evolution of the sector.

ABSTRACT. Harvesting, storage and conservation of clean and renewable energy resources are the epitomes of sustainable development. Intense research is currently in progress worldwide on all these three fronts to develop next generation device systems which would be mostly based on earth abundant materials and would be lightweight, inexpensive, hazard-free, and durable.

In the domain of electrical energy storage, which is key to the electrically driven modern world, the current materials and device systems do not meet these criteria. Moreover the demands on the size and scale of storage systems is also diverse ranging from small units for portable hand-held and wearable devices to intermediate systems for clean transportation to large scale systems for grid storage. Also, robust and efficient energy storage is needed even for the energy derived from conventional sources. These considerations have intensified search for new materials and novel device concepts for effective storage of electrical energy. In my talk I will capture the essence of this rapidly evolving story through some examples derived from own work. This will include discussion of device systems such as supercapacitors, pseudo-capacitors, Li and Na ion batteries, and Li ion hybrid electrochemical capacitors (Li-HEC).

References: J. Mater. Chem. A, 2015, 3, 1208; Small, 2014, 10, 4395;  Energy and Environ. Sci., 2014, 7, 728; Electrochimica Acta, 2014, 130, 766; Nanoscale, 2014, 6, 4387; ACS Appl Mater and Interfaces, 2014, 6 ,18844; Energy Fuels 2014, 28, 4233; Carbon 2014, 80, 460;  Electrochimica Acta, 2014, 146, 218; Energy & Environ. Sci., 2013, 6, 1249; Small, 2013, 9, 2801; ChemSusChem, 2013,  6, 2240; ChemSusChem, 2013, 5, 2159; J. Mater. Chem., 2013, 22, 11140, Nano Energy  2013, 2, 5, 890; Nano Energy, 2013 2, 6, 1158; J. Mater. Chem. A, 2013, 1, 13932.

ABSTRACT. The word “sustainability” has been applied to resources such as energy and water, in addition to products, processes, urban infrastructure such as a city, or a quasi-natural infrastructure such as an eco-system. While there have been reasonable attempts made to evaluate the sustainability status of product and process systems from economic, environmental and societal impacts perspectives, no such systematic or rigorous analysis has been attempted for energy as resources systems. 

Sustainability analysis of energy systems needs to be integrative of economic, ecological and societal constraints.  System scale chosen for an analysis defines its sustainability objectives, be they technical or policy-oriented. Thus an energy system can be an energy producing installation, such as a coal or natural gas-fired or nuclear power plant, or the system can include regional or national energy producing ventures, or it can be in the context of a watershed, thus bringing in water-energy nexus issues.  The impacts of such systems on societal and ecological wellbeing constitute sustainability analysis.  The purpose of such an analysis is to provide sustainable solutions, either by retrofitting or installing newer approaches. In a community setting, such solutions must be acceptable to the stakeholders.  Thus the solutions will be simultaneously technical and deliberative. Research must confront the challenges offered by this complexity.

ABSTRACT. Biomass is a renewable energy source which can be conveniently converted into fuels like producer gas via gasification process. This study is mainly focused on two dimensional modelling and simulation of biomass gasification in a bubbling fluidised bed reactor using the commercial computational fluid dynamics (CFD) solver ANSYS Fluent 14.0. CFD modelling includes analysis of fluid dynamics, temperature distribution and gasification process in a fluidised-bed biomass gasifier. Three phases are considered in the model and and the physical parameters pertaining to these phases are solved using Eulerian-Eulerian approach. In this work saw dust is considered as the biomass and sand, as the bed material. For a better understanding of the biomass gasification process, the impact of equivalence ratio (ER), steam to biomass ratio (SBR), preheating of air and steam temperature is analysed. It is found that, when ER is increased from 0.15 to 0.4, H2 concentration is decreased by 72% and the variation of SBR from 0.5 to 1.5 enhances the H2 concentration by 87%.

ABSTRACT. Oxy-fired fluidized bed combustion is one of promising technique which serves a dual purpose i.e. benefits of fluidized bed combustion and oxygen firing technology. India, being a diversified country has a vast resource of biomass which includes agricultural waste, organic matter, forest waste etc. Pine needles (PN) which are forest biomass are abundantly available in the hills of North India and its proper utilization will strengthen the economy as well as reduces the pollution. Co-firing with oxy-fired fluidized bed has potential for negative CO2 emission level for power generation. Co-firing at low percentages of the thermal power (typically below 5-10 %) avoids the characteristic operating problems of biomass combustion. The present work extensively investigate the temperature profile, flue gas emission and the performance of co-firing coal with pine needles under air-fired and oxy-fired condition in a 20kW bubbling fluidized bed (BFB) combustor. Five different ratios of coal and pine needles are considered for this study are 100%/0%, 75%/25%, 50%/50%, 25%/75% and 0%/100%. Combustion observed under control and stable for the blend when pine needle share is in-between 25% to 50%. Maximum combustion efficiency of 97.05 % could be achieved with 75%coal/25%PN under oxy-fired condition. The measured percentage of NOx and other gases are found in permissible limit.The short fluidized bed combustor of 1.8 m in length is made from financial grant obtained from DST New Delhi India.

ABSTRACT. Experiments were conducted to obtain the performance and emission characteristics of rubber seed oil methyl ester (B100) by using single cylinder four stroke variable compression ratio (VCR) diesel engine at constant speed (1500 rpm) without any modification in the engine. Different characteristics of B100 were investigated by varying the load in increasing order [no load (0%) to full load condition (100%)] and by varying the compression ratio 14:1, 15:1, 16:1, 17:1, and 18:1 for each of five load conditions varying from no load to full load; and compared with performance and emission characteristics of diesel (B0) obtained at compression ratio 18 at different load conditions. Performance characteristics like indicated power, brake power, brake thermal efficiency, volumetric efficiency, brake specific fuel consumption were investigated. Emission characteristics like exhaust gas temperature, carbon monoxide, carbon dioxide, and NOx were also investigated.

ABSTRACT. Experimental investigation is carried out in open top downdraft biomass gasifier for studying reaction front propagation rate and variation in gas quality in the packed bed reactor. The study includes conditions both with and without secondary air in to the reactor. It is established that in at certain range of ratios of primary to secondary air flows, entry flame front stabilized near the secondary air nozzle. Effect of moisture content in the fuel is studied for different secondary to primary air ratio. It is found that the propagation rates are lower for fuel with higher moisture content. Variation in gas composition with different ratios of secondary to primary air for a range of moisture content in the fuel is studied. The effect of the ratio of secondary to primary air on gas calorific value is evaluated. The results of the work is presented with their associated observations.

ABSTRACT. Demand of electricity is increasing rapidly due to continuous economic, social and industrial development. It is forecasted that energy consumption would grow by 56 % by 2040. Electricity demand is the major part of the world’s total energy demand. Among the different energy sources, coal provides 40% of the total worldwide electricity generation. The CO2 emission from the power industry has been identified as a major source of GHGs emission. Old, yet operating, coal fired plants are the poorer performers, both in terms of efficiency and emission. In this context, repowering of old existing plants can address the present need of capacity augmentation and performance improvement in an environment friendly way. This study deals with repowering of an old operating 250MW coal fired power plant through integration of a molten carbonate fuel cell (MCFC) system at the downstream of the power plant. Two different schemes of integration have been investigated. A high temperature molten carbonate fuel cell (MCFC) plant receives the boiler exhaust in its cathode stream and its anode is fed with a hydrogen-rich syngas generated from natural gas in an external reformer. The fuel cell works at atmospheric pressure and 650º C. Heat in the MCFC exhaust is further utilized in a waste heat recovery network for heating the boiler exhaust and the fuel for the reformer and generation of steam, to be used in the reformer. A 250 MW plant is considered for repowering which is shown in fig. 1. The existing and repowered plants are modelled using Cycle Tempo simulation software.

ABSTRACT. Co-gasification of coal and biomass improves the gasification process by reducing the amount of tar generated and also produces a low carbon footprint on the environment. In this study, Chemical Equilibrium with Application Program (CEA), a non-stoichiometric equilibrium model, developed by NASA, based on Gibbs free energy minimization technique has been used to study the thermodynamic optimization of coal-biomass co-gasification process. Simulation of the co-gasification process has been done to evaluate the product gases from gasification process for various coal-biomass mixtures at different equivalence ratio and temperature. The simulation result shows as the gasification temperature increases, the CO molar fraction increases for a particular equivalence ratio and reverse is the trend for CO2. Again, the CO molar fraction increases with a decrease in equivalence ratio for all the gasification temperature and reverse in case of CO2. The study also observed that as the percentage of coal increases in the fuel mixture, mole fraction of CO increases at a particular ER with increase in temperature. However, a reverse trend is observed in case of CO2. The mole fraction of H2 decreases with the increase in coal percentage for all gasification temperature for a particular equivalence ratio.

ABSTRACT. Energy conservation is a sustainability tool for industries. In last two decades, many innovative concepts are adopted by industries. Some of them become proven, others may need further innovation to be adapted by industry. This paper discuss innovative application of these technologies and challenges the set conventions / rules of plant operation. For example, it is conventional to keep the temperature of flue gas above Sulphur dew point. However, recovering heat and water from furnace flue gas by using condensing technologies is now feasible.. This technology can be adopted by proper material selection of downstream equipment. Similarly, adding make up water at ambient temperature is considered absolutely normal for a cogeneration plant where steam from power plant is sent for process consumption. Heat Pump is one of the intelligent solutions which can be used for heating as well chilling applications simultaneously. It helps to recover low grade energy.  Similarly use of Evaporative condenser / Evaporative cooling is not considered right for humid area, but now there are applications in humid climates also to minimize condenser approach for improving operational efficiency.

ABSTRACT. Polygeneration is the process integration of multiple utilities in a single unit to obtain an efficient multi-utility system. Biomass based polygeneration has strong potential for efficient and CO2-neutral delivery of several utility outputs for sustainable development. Thermodynamic performance estimation of polygeneration for different biomass is necessary for economic planning of it. In this work, a polygeneration with four utility outputs – power, refrigeration, desalination and utility heating using biomass is modeled in ASPEN Plus®. Eight different biomass representing different generic categories were selected as inputs. Performance variation in the form of output utilities as well as fuel saving through polygeneration for different biomass is reported in this paper. Results show that the power output mostly depends on heat values of biomass and partly on gasification efficiencies. The gain in efficiency through complex integration of multiple utilities and/or inputs in a polygeneration will be justified if the system saves fuel through this process of integration. Polygeneration with wheat straw has the lowest FESR (~20%) and that with sugarcane bagasse has the highest value (~30%) as obtained from this simulation. Thus, significant fuel saving (20%-30%) is expected through this polygeneration rather than producing four utilities in separate standard units.

ABSTRACT. Fatty acid methyl esters (FAME) also called and accepted as Biodiesel, has got a prominent importance in this new era as an alternate fuel for petro-diesel. Bio-diesel has obtained prominence due to its renewable nature, higher combustion efficiency, reduced CO and un-burnt Hydro Carbon (HC) emissions. Generally, the feed-stock used for the synthesis of bio-diesel is vegetable oils and animal fats. Production of bio-diesel in bulk quantity is constrained due to the edibility of many of these vegetable oils and limited feed-stock of non-edible oils. Microalgae provide a solution to this problem. The high production volume per hectare area of microalgae sets a new trend for research in this field. Schizochytrium is a marine microalgae and is a prolific producer of docosahexanoic acid (DHA). It has been demonstrated to have beneficial effects on human life as a dietary supplement. In addition to DHA, this microalgae contains high lipid content, which is ideal for producing biofuels. The free fatty acid content of Schizochytrium oil is 0.1%, which is well within the recommended value for one-step alkaline transesterification. In this work, the synthesis of bio-diesel was carried out using this oil with the addition of potassium methoxide (a mixture of methanol and KOH). For obtaining highest yield of FAME, essential amounts of methanol and catalyst, reaction parameters namely time and temperature are optimized. The yielding of FAME was confirmed by Gas Chromatography with Mass Spectroscopy (GC-MS) for each trial of experiment. A conversion efficiency of 99.99% was observed through GC-MS analysis for a 30% v/v methanol, 0.4% w/v KOH, 60°C reaction temperature and 90 min reaction time. The results were complemented by proton nuclear magneto resonance (1H NMR) spectra and it is found that the synthesized fuel properties were well within the limits of ASTM standards.

ABSTRACT. This work has the objectives of producing reducing sugars from spent Java citronella (Cymbopogon winterianus Jowitt) biomass using subcritical water (SCW) treatment in a batch reactor system. The effect of process parameters such as temperature (140-220 °C) and reaction time (5-40 min) affecting the total reducing sugar (TRS) yield was studied. The production of TRS increases with temperature from 140-160 °C and thereafter decreases. The maximum amount of TRS 132.09 mg/g biomass was obtained at 160°C and 30 min reaction time. The formation of sugar inhibitors (5-HMF or Furfural) was almost insignificant upto 160°C, but sugar degradation subsequently increased with an increment of reaction temperature and time. The maximum inhibitors concentration of 16.70 mg/g was obtained at 220°C and 30 min reaction time, which includes 5.77 mg/g of 5-HMF and 10.93 mg/g of furfural. The crystallinity index (CI) value of the biomass sample increased from 35.30% to 52.68% with an increase of reaction temperature from 140-180°C, further increased in the temperature to 220°C decreases the crystallinity index (CI) abruptly to 20.15% thereby altering the biomass to relatively amorphous.

ABSTRACT. Natural deep eutectic solvents (NADES) are recently developed “green solvents” consisted of bio-based ionic liquids and deep eutectic solvents mainly from plant based metabolites. NADES are biodegradable, non-toxic and environment-friendly. Conventional chemically synthesized ionic liquids have been tested for pretreatment of lignocellulosice materials but are toxic, expensive, and energy-intensive for recycling. We have developed an integrated zero-waste cellulosic ethanol technology for high-purity lignin removal, solvent recovery and reuse, ethanol fermentation. The investigation includes cellulosic ethanol production in 10 different NADES-pretreated rice straw and the effect of NADES on performance of the commercially available cellulase Cellic Ctec2 and cellobiose-fermenting yeast strain Clavispora NRRL Y-50464. Using NADES prereated rice straw, a maximum reducing sugars of 226.7 g L-1 was obtained with a saccharification efficiency of 87.1 % at 20% solids loading and 12 FPU Cellic Ctec2 enzyme. An ethanol production of 36.7 g L-1 was observed from 8% of glucose within 36 h with a conversion efficiency of 90.1%.

ABSTRACT. Solid oxide fuel cell (SOFC) has been emerging as an important class of power generation device as it can be operated on different hydrocarbon fuels through electro-oxidation at anode. Anode supported SOFC has been extensively investigated because of ease of fabrication and high performance. Ni-YSZ cermet anodes of SOFC have showed an excellent catalytic properties and stability for H₂ oxidation but not for hydrocarbons as it results in very fast carbon deposition. Carbon deposition covers the active sites of the anode, resulting in rapid irreversible cell deactivation. A significant amount of steam must be needed to induce the steam reforming reactions in order to prevent the carbon deposition but it lowers the electrical efficiency of the system. The development of anode catalyst for direct hydrocarbon solid oxide fuel cells (SOFCs) with improved electrochemical properties and durability remains a major research interest [1-5]. Alternative anode materials such as copper-ceria-YSZ were thus developed which significantly reduced the coke formation [5-7]. Thermal instability and poor electrochemical activity of copper-ceria-YSZ anodes at the solid oxide fuel cells (SOFC) operation temperature (>700 °C) necessitates the use of new strategy to improve the performance of respective anodes fed with hydrocarbon directly.  In this work, electrochemical behavior of Cu/CeO₂-YSZ, Cu-Fe/CeO₂-YSZ and Cu-Co/CeO₂-YSZ anodes is studied in hydrogen, methane and butane fuels. SOFCs are fabricated in laboratory scale using tape casting technique with thickness of < 600 µm and anode porosity of ~70 %. The additives composition (solvents, binders and pore-formers) is optimized to fabricate defect free SOFCs. The wet impregnation method is used for incorporation of CeO₂, Cu, Fe and Co in porous YSZ to prepare the anodes. XRD shows that Cu, Co and Fe metal phases are present in cubic structure after reduction in H₂ at 800 °C with crystallite size of ~ 0.15 µm. SEM and elemental mapping shows higher distribution of catalyst particles achieved inside the pores of anodes with addition of Co and Fe in Cu/CeO₂-YSZ anodes, which is useful to provide higher electrical conduction.

The current voltage characteristics of prepared anodes are measured for different metal loadings and molar ratios using yttria-stabilized zirconia (YSZ) as electrolyte and strontium doped lanthanum magnate (LSM) as cathode. The maximum power densities of approximately 200 and 320 mW/cm² at current densities of 380 and 520 mA/cm² are observed for Cu-Fe/CeO₂-YSZ anodes with Cu-Fe molar ratio of 1:0 and 1:1 in H₂ fuel at 800 °C. In CH₄ and n-C₄H₁₀ fuels, power densities of 120 and 250 mW/cm² at current densities of 240 and 380 mA/cm² are observed for Cu-Fe/CeO₂-YSZ anodes with Cu-Fe molar ratio of 1:1. Cu-Fe/CeO₂-YSZ anodes with Cu-Fe molar ratio of 1:1 showed higher performance in comparison to molar ratio of 1:0 and 3:1[5-8]. The fitted electrochemical impedance spectra suggests that  improved power and current densities of Cu-Fe/CeO₂-YSZ anodes in comparison to Cu/CeO₂-YSZ anodes are due to less ohmic as well as charge transfer resistances in SOFCs. Furthermore, the performance of Cu-Fe/CeO₂-YSZ anodes increases with the increase in temperature, Cu-Fe metal loading and with addition of Pd in Cu-Fe/CeO₂-YSZ anodes. For continuous 40 h cell operation in H₂, CH₄ and n-C₄H₁₀ fuels, no apparent degradation in performance of Cu-Fe/CeO₂-YSZ anodes is observed. The carbon fibre formation is observed after exposure of n-C₄H₁₀ fuel which actually increased the performance of SOFCs due to conductivity provided by carbonaceous species. The reactant gas can reach to surface of the catalyst through the fibres as well as interstices of the fibres which might be the reason that cells performs for longer period of time.  The results suggest that Cu-Fe/CeO₂-YSZ anodes exhibits better stability than conventional Ni-YSZ anodes [6, 8].

Moreover, effect of Cu-Co loading on the performance of Cu-Co/CeO₂-YSZ anodes is investigated in H₂ and n-C₄H₁₀ fuels at 800 °C. The objective is to study the micro structural changes and long term stability of Cu-Co/CeO₂-YSZ anodes in n-C₄H₁₀ fuel which has not been reported in literature. Cu-Co/CeO₂-YSZ anodes with Cu-Co loadings of 10, 15 and 25 wt% achieved maximum power densities of 60, 197 and 400 mW/cm² in H₂ and 190, 225 and 275 mW/cm² in n-C₄H₁₀ fuel at 800 °C. During cell operation in n-C₄H₁₀ fuel, total resistance decreased for 10 and 15 wt % Cu-Co loading while it appears to increase for 25 wt % of Cu-Co loading. SEM and TGA suggest that the amount of carbon deposition increases with increase in Cu-Co loadings resulting increase in polarization resistance of cell [6, 7]. The higher amount of carbon formation increases the diffusion resistance and decreases the three phase boundary surface area for the electrochemical oxidation of fuel. HRTEM and EIS suggest that metal particles are detached from the surface of anode by trapping of the catalyst particles in the carbon fibres and thereby decreased the performance of the cell. The performance degradation from 280 to 110 mW/cm² is observed during 16 h cell operation in n-C₄H₁₀ fuel due to increasing amount of carbon deposition with time.

References

1. R.J. Gorte, S. Park, J.M. Vohs, C. Wang, Advanced Material, 12 (2002) 1465.
2. C.M.  Andersson, H. Paradis, J. Yuan, B. Sundén, International Journal of Energy Research, 35 (2011) 1340.
3. S. Park, R. Craciun, J.M. Vohs, R.J. Gorte,  Journal of Electrochemical Society, 146 (1999) 3603.
4. E.P. Murray, T. Tsai, S.A. Barnett, Nature, 400 (1999) 649.
5. Kaur, G., and S. Basu, J. Power Sources 241 (2013) 783-790
6. Gurpreet Kaur and Suddhasatwa Basu, ECS Trans. 57(1): 2961-2968 (2013)
7. G Kaur, S Basu, Fuel Cells, 14(6), 1006–1013 (2014)
8. Gurpreet Kaur, Suddhasatwa Basu, Int J Energy Res, 39, 1345–1354 (2015)

ABSTRACT. The development of zinc bromine redox flow battery technology is experiencing a critical challenge due to the slow kinetics of bromine which results in poor efficiency of the cell. Here, we demonstrate a comparative electrocatalytic effect of platinum, graphite and graphite/single-walled carbon nanotube (G/SWCNT) composite electrodes for the 2Br–/Br2 redox couple for zinc bromine redox flow battery application. The anodic peak current density of G/SWCNT electrode is found to be higher than that of pristine Pt and graphite electrodes, indicating the enhanced electrocatalytic effect of G/SWCNT perhaps due to the incorporated basal planes. The peak separation between the anodic and cathodic process of graphite and G/SWCNT electrodes is 225 and 160 mV, respectively, demonstrating the quasireversible nature of the 2Br–/Br2 redox reaction. Further characterizations of composites electrodes are carried out using FTIR, Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) before and after cycling. The electrochemical performance and characteristic of the zinc bromine flow cell fabricated with graphite and G/SWCNT as electrodes will be discussed in detail.

ABSTRACT. A simple one step solvothermal method was used for the synthesis of magnetite (Fe3O4) nanoparticles on Nitrogen doped reduced graphene oxide (NrGO). Ferric chloride (FeCl3) was used as magnetite precursor and glucose, urea were used for size control of magnetite nanoparticles and nitrogen doping of reduced graphene oxide respectively. X-ray diffraction results show that magnetite nanoparticles were successfully formed with simultaneous reduction and N-doping on graphene oxide. Transmission electron microscopy images show that magnetite nanoparticles formed were uniformly dispersed. Fourier transform infrared spectroscopy shows the N-doping of reduced graphene oxide and Fe-O stretching. The electrochemical properties of Fe3O4@NrGO were investigated with carbon sheet as support material. This nanocomposite showed better specific capacity than Fe3O4 and Fe3O4@rGO. Specific charge discharge capacity of upto 280 F g-1 at 0.5A g-1 was exhibited by the as-synthesized nanocomposite. Nitrogen doping has enhanced the specific capacity of the nanocomposite. Stability tests had to be performed and will be discussed in final manuscript

ABSTRACT. A novel microencapsulated phase change material (PCM) based on agar gel with ethyl cellulose/methyl cellulose (EC/MC, weight ratio 2:1) polymer shell was synthesized. A novel liquid to liquid encapsulation and in-situ polymerization method was adopted for the synthesis of microparticles and their various thermo-physical properties were studied for their use as latent heat thermal energy storage (LHTES) system in the cooling tower units. Two different heating and cooling cycles of differential scale calorimetry (DSC) thermograms indicated the successful encapsulation of the PCM. Scanning electron microscope (SEM) images showed that the particles are spherical in shape with smooth and compact encapsulation and there is negligible volume change during phase transition of the PCM. Dynamic light scattering (DLS) revealed the uniform size distribution (average size ≈ 12 µm) of the encapsulated particles. Thermal gravimetric analysis (TGA) indicated good thermal stability of the fabricated microcapsules. Moreover, good thermal conductivity was observed, thus overcoming two major concerns of existing organic PCMs viz. low thermal conductivity and large volume change during phase change from liquid to solid and vice-versa. Furthermore, the encapsulated microparticles showed good water dispersion ability thus making them suitable for use (dispersed in circulating water) in cooling tower units.

ABSTRACT. In this paper, we present hydrodynamic studies of conventional, parallel and serpentine flow field for all-vanadium redox flow battery applications. Computational fluid dynamics (CFD) simulations of electrolyte flow distribution in the flow fields shows that a non-uniform flow distribution is established in parallel flow field and a very large pressure drop occurs in conventional flow; serpentine flow fields offer optimal solution in terms of nearly-uniform flow distribution with reasonably low pressure drop. The key to both pressure drop in conventional flow fields and under-the-rib convection in serpentine flow fields is the permeability of the electrode under compression. These have been determined experimentally for two commercially available carbon felts. Experiments have been conducted to measure the pressure drop with both felts in serpentine flow fields. The result show that SGL carbon felt gives 55% higher pressure drop as compared to the carbon felt from Alfa Aesar. Experiments are in progress to study electrochemical behavior with both the felts.

ABSTRACT. Semiconductor quantum dots (QDs) as solar harvesters constitute a promising approach towards low-cost third-generation photovoltaic devices owing to their band gap tunability, high absorption coefficient, solution processability and multiple exciton generation. Although QD solar cells (QDSCs) are expected to cross the Shockley-Queisser power conversion limit of ~32%, the device performance have only reached moderate power conversion efficiencies (PCE) of 6–8% due to interfacial charge recombination at the TiO₂/QD-electrolyte interface which drives back the photo-generated electrons into the oxidized polysulfide electrolyte. This lecture will discuss few validated strategies with colloidal QDs to improve the PCEs. The first strategy is heteroatom doping in QDs to increase the lifetime of excited charge carriers and mitigate the deleterious charge recombination at the interface. Maximal substitutional doping of Mn²⁺ ions inside CdS QD lattice could boost the PCE by 66.4% as compared to undoped CdS solar cells.¹ Secondly dual sensitization through linker-assisted self-assembly of CdTe/CdS core/shell QDs on porous TiO₂ and deposition of another CdS quasi-shell could achieve PCE as high as 6.32(9)% (6.41% for the champion cell), the highest for any aqueous processed QDSC.² Third, combinations of graphene oxide ribbons and Cu_xS nanostructures with tuned Cu:S stoichiometry in the counter electrode could boost the PCE further to 6.81(8)%.³

References

(1) G. Halder and S. Bhattacharyya, J. Phys. Chem. C 2015, 119, 13404-13412.

(2) A. Sahasrabudhe and S. Bhattacharyya, Chem. Mater. 2015, 27, 4848-4859.

(3) D. Ghosh, G. Halder, A. Sahasrabudhe and S. Bhattacharyya, 2015 (Unpublished).

ABSTRACT. Two dimensional metal chalcogenides turned as promising candidate for optoelectronics owing to their interesting Physical and Chemical properties. In the present work, 2-D layer structured CuSe nanosheets were developed by simple hot injection method. Oleic acid has been employed as solvent as well as capping agent and CuCl, elemental sulfur have been used as precursors at the reaction temperature of 220^oC. Crystallinity and Phase of the products were characterized by X-ray diffraction (XRD). XRD patterns confirm the presence of hexagonal Klockmannite (CuSe) with space group of P63/mmc. Morphological analyses were carried out through SEM analysis which depicts the 2-D layered nanosheets of CuSe with the two different orientations of nanosheets. Elemental composition of copper to selenium ratio was confirmed through Energy dispersive X-ray spectroscopy (EDS) which reveals the stoichiometry of CuSe nanosheets. The EDS results are very much analogues to the XRD results. The presence of capping agent over the CuSe nanosheets were confirmed from Fourier transform infrared spectroscopy (FT-IR).

ABSTRACT. The process of sunlight transmission through optical fibers has received considerable interest from the scientific community in recent times. The interdisciplinary emerging field has found many applications in the field of solar lighting, solar furnace, three dimensional solar cells etc. Most of the optical fiber based solar lighting systems have employed plastic fibers as the light transmission media and the use of silica fibers in such systems has not been given much attention. Further, the actual measured data/values of the light emanating from the output ends of fibers in such systems are rarely reported. In the present study, merits and demerits of employing silica and plastic fibers in transmitting sun light are discussed. A silica optical fiber based solar lighting system has been developed and after installing it on an indigenously fabricated sun tracker, its performance has been measured and reported. Based on experimental and simulated results, multimode silica fibers could turn out to be better light transmission media than the plastic fibers, particularly for the case when light has to be transported over longer distances. The findings reported herein stress the need for tailor made customized solar lighting design for different buildings.

ABSTRACT. Enhancing photon absorbance efficiency along a broad range of the electromagnetic spectrum followed by facilitating ultrafast transfer of that excitation is an important aspect of photovoltaic research. The same process is carried out in plants and green-bacteria during photosynthesis with ~96% efficiency1. Designing bio-inspired, low-cost solar energy conversion systems using natural chromophores is the recent trend in energy research. In natural photosystem highly packed perfectly oriented array of Chlorophyll molecules(mostly Chlorophyll-a in higher plants), also known as light harvesting antenna complex (LHC), collect and direct light energy towards a special pair of pigments where photosynthesis begins2. This process precisely involves conversion of solar energy into chemical energy by creation of a pair of oxidant and reductant resulting from electron ejection from Chlorophyll to an acceptor3. Although the concept of using Chlorophyll pigments or photosystem in solar cells goes back to 1970s4, thorough evaluation of its interaction with different inorganic and organic systems for application in photovoltaic has started very recently5. Lai et. al. (2008) successfully used Chlorophyll adsorbed TiO2 photo-electrode in a water based DSSC6. Spontaneous electro-chemical solar water splitting has been demonstrated by Ager et. al7. All the reported systems however are subject to many fold development. The main challenges in using Chlorophyll molecules in solar cells are: A) Isolated Chl molecules cannot harvest photon efficiently, they absorb excitation energy only in narrow regions of the spectrum, a major part of which is lost as heat. B) Sometimes potentially hazardous triplet states are formed via inter-system crossing which affect excitation energy transfer. C) Isolated pigments are prone to degradation. But in natural photosystems the environment, comprising mainly of protein, facilitate superfast excitation transfer by minimizing such effects. Coupling between closely packed molecules and pigment-protein interaction results in broader absorbance cross-section and faster charge or energy transfer besides reducing wasteful intersystem crossing. The present work aims to evaluate Chl-a entrapped chitosan hydrogel as a candidate material for light harvesting component of solar cell. Hydrogels are three dimensional array of cross-linked biopolymers capable to encapsulate huge amount of (~90% of their weight) water and biomolecules. Reaction rate and ion transport properties in “quasi-liquid” hydrogels are comparable to that in liquid media, making them a good alternative of hazardous volatile electrolytes used in conventional dye sensitized solar cells. H. K. Jun has used organic ions embedded in aqueous gel media to construct a biomimetic solar cell having good energy conversion efficiency8. In this work emphasis is given on study of exciton dynamics through self-assembled Chlorophyll-a molecules in a chitosan hydrogel scaffold by photo-physical and electrochemical data analysis. Knowledge of excitation migration and oxidation-reduction rates may be highly useful in development and optimization of bio-inspired light harvesting complexes using Chlorophyll as a key element. Absorbance spectra of CScl (Fig.1.) shows significant inhomogeneous broadening up to 900nm indicating inter-molecular interaction besides molecule-matrix interaction. Strong coupling between adjacent pigment molecules results in delocalization of electron cloud further causing broadening of electron transition spectra. This spectrum remains same for nearly 4 months depicting successful stabilization of Chlorophyll-a molecules inside the hydrogel. Time correlated fluorescence studies show very short excited state lifetime which imply most of the pigments participate to form molecular assembly within the matrix. Signature of different species can be depicted in agreement with absorbance data. Comparing absorbance, time correlated fluorescence, fluorescence anisotropy data it may be depicted that ultrafast excitation hopping occurs within coupled molecular species, similar to natural photosystem9. The cyclic voltammetry curve of the as prepared gel (Fig.2.) shows Chlorophyll reduction peak around 0.5 volt and reversible nature.

ABSTRACT. Electrocatalysis is of having paramount interest in many modern energy technologies. Various catalysts have been reported in the literature, and metal/metal oxide based catalysts are the benchmarked ones among them. The success of graphene research surged the development of nanoparticle free graphene based catalysts and recently, graphene based multifunctional catalysts have been developed. Here we investigate the multifunctional catalytic properties of other atomic layers, namely metal chalcogenides (MX, M: metal, X: chalcogen). First principle calculations using Density Functional Theory is conducted to understand the role of doped elements (here metals) towards the electrocatalytic efficacy of MX. The electrocatalytic reactions such as oxygen reduction reaction, oxygen evolution reaction and hydrogen evolution reaction are studied in detail, and the role of metal dopants in the electrocatalytic properties of MX is unraveled.

ABSTRACT. Almost forty-percent of global coal-fired power is supplied by brown coal or lignites, collectively termed as low-rank coals. In Australia, brown coal supplies about 20% of total power. However, low-rank coals also represent the more polluting power stations in general. Therefore, there is a strong incentive to develop technologies capable of cleaner power generation from coal, and low-rank coals in particular. One such technology which has captured growing interest in recent years is Chemical Looping Combustion (CLC). CLC is a new technology with inherent CO₂ capture for subsequent storage. CLC operates on the principle of oxygen transfer from metallic oxides called oxygen carriers to combust the fuel in the absence of nitrogen, generating a concentrated stream of sequestration-ready CO₂. The oxygen carriers are then separated, re-oxidized in a secondary reactor with air, and reused. When compared to other Carbon Capture and Storage (CCS) technologies, CLC has the advantages of lower cost and lower energy penalty. Additionally, by using oxygen carriers instead of air for the combustion of fuel, CLC eliminates the primary source for the formation of NO_x. Investigations on CLC have focused mainly on gaseous fuels, but over the past decade, interest in the application of solid fuels for CLC has been increasing. Although majority of the work has focused on black coal and metallurgical/petroleum coke as fuel, results from investigations of brown coals and lignites, both locally and globally, have shown that it is a suitable fuel and has several distinct advantages for use in CLC. Of late, the principle of chemical looping has also been extended to chemicals production. This presentation provides a status review of the Chemical Looping research worldwide and that at Monash University in particular for use with low-rank coals.

ABSTRACT. Biomass is getting increased attention as a potential source of future energy as it provides long term solutions with respect to global issues of sustainable energy and greenhouse gases reduction. Biomass gasification is being looked upon as one of the most efficient methods for the extraction of energy contained in biomass. The present work focuses on simulating the production of syngas from biomass (rice husk) using ASPEN Plus simulator. The developed model is capable of simulating pyrolysis, tar cracking, combustion, and reduction (gasification) reactions. The model was used for comparing air, steam and air-steam gasification. For air-steam gasification the maximum hydrogen yield predicted by the model for a steam to biomass ratio of 1 and temperature of 1000 K is 36.13% by volume of syngas at an equivalence ratio of 0.25.

ABSTRACT. The present paper describes the numerical investigation of the Wells turbine for extracting energy from the oscillating water column (OWC). The present work was performed to understand the effect of backward swept blade on the Wells turbine performance. The numerical analysis was carried out by using commercial software ANSYS CFX® v14. 0. Two different blades were used: unswept blade and 10o backward swept blade, respectively.It was found that the backward swept blade was strongly affected on blade stall margin. It was also observed that the separation of the flow occurs near the trailing edge where as unswept blade the flow separation occurred near the leading edge.

ABSTRACT. Lignocellulosic feedstock is one of the potential renewable sources for producing ethanol. However, technological bottlenecks and economic viability are of prime concern in producing ethanol from the lignocellulosic feedstocks. The present work aims at optimizing the dilute acid pre-treatment of lignocellulosic feedstock, which is the first major processing step in ethanol production. A batch reaction kinetic model for acid pretreatment of sugarcane bagasse is first developed from literature by considering the major feedstock components and their decomposition into desired and degradation products. Subsequently, the kinetic model is augmented to develop a batch reactor model, including the associated heat balance. Optimal control has been proposed to determine the optimal time dependent temperature profiles for performance optimization. Different objective functions such as maximizing concentration of xylose, maximizing xylose concentration in minimum time, and minimizing processing cost have been considered. The results are expected to provide the optimal operating strategies to improve techno-economic feasibility of dilute acid pretreatment.

ABSTRACT. The negative temperature coefficient is a phenomenon occurring in some fuel-air mixtures that results in reduction in system temperature for increasing inlet temperatures. Standard kinetic models are essential tools that help predict this phenomenon and such studies are of practical importance for designing practical combustion facilities or reformers. There has been considerable work in the methane-air ignition studies, however detailed study of negative temperature coefficients at higher pressures is not found in literature. Further, the effect of changing the co-reactant to oxygen and addition of steam has not been hitherto studied in detail. In this work, we adapt multiple reaction mechanisms from literature and compare them for methane oxidation at high pressures. In this perspective, the autoignition delay time of methane air mixture have been evaluated in dependence of temperature by using several reaction mechanisms. The key reactions responsible for NTC behaviour have been identified using reaction path analysis and sensitivity analysis. At the same time, the dependence of temperature on the NTC is also discussed.

ABSTRACT. 47% of UK energy consumption is in the form of heat – associated with domestic and commercial heating of buildings, and the heating requirements for a wide range of industrial processes.  Since many heating requirements rely ultimately on the combustion of fossil fuels, inevitably this has a major impact on emissions of CO₂.  Furthermore, with the ever-increasing price of fuel and electricity, there are significant economic impacts for both domestic and industrial customers.  Hence there is a very strong driver towards the exploitation of renewable heat, and a key challenge for renewable heat must be effective heat storage.

This presentation will describe the development of a compact heat store (known as a Sunamp Heat Battery) that can replace domestic boilers, hot water tanks and air conditioning units, and can connect to solar panels and other forms of renewable energy heating and cooling equipment.  A key technology component of the store is the use of Phase-Change Materials (PCMs) that absorb heat and undergo a phase transition, e.g. dissolution or melting.  Although PCMs based on salt hydrates offer several advantages over organic materials, they often suffer from disadvantages of incongruent melting and sub-cooling, resulting in non-reproducible performance and poor long-term stability. These factors can severely their use of this material as a PCM.   

We have overcome both of these problems and have developed additives that suppress the formation of the anhydrous salt, together with nucleating agents that prevent sub-cooling.  Using in situ X-ray powder diffraction, we have interrogated in real time the structural and chemical evolution of these formulations during repeated temperature cycling, and have identified the mechanisms by which nucleating agents can be thermally deactivated by excessive heating.  These new PCM formulations retain their high energy densities and have been incorporated in Sunamp Heat Batteries, which are currently being used in domestic applications in order to balance electrical demand from the grid, store solar thermal energy, and reduce heating bills for customers. 

ABSTRACT. Si wafering in photovoltaic (PV) manufacturing accounts for 11% of final module cost. Therefore, cost savings realized at this process step significantly impacts the $/Watt of PV modules. Diamond coated wire (DCW) sawing of Si ingots aims to minimize wafering costs with concurrent advantages of higher cutting rates and significantly less environmental impact through minimal use of cutting fluid.

In DCW, millions of diamond microparticles embedded on thin steel wires mechanically saw solar Si ingots into wafers. The process is highly complex and stochastic. In this presentation, I will talk about fundamental insights on the DCW cutting mechanism using micro-Raman spectroscopy on i) the diamond microparticles and ii) the Si kerf (particulate waste produced due to sawing).

First, I will show that diamond microparticles undergo stress based phase transformation into a softer graphitic phase. The soft graphitic phase is responsible for loss in cutting efficiency. Second, I will show that by studying individual Si kerf particles, correlations between particle shape and phase is established. Fibrillar Si kerf are found to be amorphous – indicative of a ductile cut; while particulate Si kerf are crystalline – indicative of a brittle cut. Ensemble measurements of Si kerf allows us to quantify the rates and efficiency of cutting and predict changes to DCW cutting quality. These results are in-line with finite element modeling of diamond interaction with Si surface.

The take home message is that micro-Raman spectroscopy can prove to be a valuable diagnostic tool for assessing machining of solar Si ingots where the collective cutting efficiency of millions of diamond microparticles can be monitored and quantified.

ABSTRACT. We report developing a tunable, facile and inflatable way to synthesize TiO2 nanofloral array on a Ti foil under moderate atmospheric conditions. The nanostructure were synthesized by thermochemical digestion of titanium by peroxide and fluoride (Fˉ) ions in the solution. The nature of nanostructure was dependent upon the availability of oxidizing species along with temperature and duration of digestion. The resultant oxide comprised TiO2 when digested in Fˉ rich solutions whereas it contained Ti2O3 on digestion in solution with weaker Fˉ concentration. Though, the growth of TiO2 nanoflowers increased with increasing concentrations of Fˉ ions, no distinct structure could be observed at too low as well as too high concentrations. Also the prematurely or over-agedly digested samples too, showed no identifiable nanostructure. The optimum growth time was found to be 60 hours at bath temperature of 65-75°C. The as-grown TiO2 nanoflowers of size 100-150nm was found to be highly stable and shear resistant. Multi-location XRD analysis of air annealed samples indicated uniform presence of Anatase (101) and Anatase (200) crystals of about 20nm size. AFM estimated that the available TiO2 nanostructural surface area was more than 2600 times of the initial Ti surface area. This new area, unlike nano-tubular structures’ surface area, was openly accessible by sheet forming sensitizers like graphitic carbon nitride for creating better heterojunctions.

ABSTRACT. Abstract: In this work, green synthesis of gold nanoparticles (AuNPs) using the aqueous extract of Phyllanthus emblica (locally known as emblic) as reducing and capping agent was carried out. The synthesized AuNPs were mixed with titanium dioxide (TiO2) nanoparticles and used for the preparation of photoanode for a dye sensitized solar cell (DSSC).The optical properties and crystalline structure of green synthesized AuNps were studied by UV-vis spectroscopy and X-ray diffraction (XRD). The AuNPs mixed TiO2 nanoparticles were subjected to morphology, size, crystalline phase and elemental compositional analysis by FEG-TEM, XRD and FESEM with EDS. The photoanode was fabricated using this AuNPs mixed TiO2 NPs paste by forming a thick film on a fluorine doped tin oxide (FTO) glass substrate by doctor blade method. The resulting DSSC was characterized by current voltage (I-V) measurement, electrochemical impedance spectroscopy (EIS) and incident photon to current conversion efficiency (IPCE) measurements. The electron transport mechanism and internal resistance of the DSSC were analyzed by EIS. The paper will discuss all of these results in detail.

ABSTRACT. Solar Photoelectrochemical (PEC) water splitting is a process of semiconductor-assisted decomposition of water into hydrogen and oxygen in the presence of sunlight. Several materials systems have been and are being examined in this context but the current drive is towards the use of non-silicon, earth-abundant nanostructured materials in the interest of cost effectiveness. Among various nanostructures, quasi 1D nanostructures (nanorods, nanowires, nanotubes) have been attracting quite an attention recently because they provide a direct pathway for efficient and confined charge transport along with more surface accessibility for the electrolyte, which is useful for efficient PEC cell.

Cuprous oxide (Cu2O), a p-type semiconductor, is currently attracting attention of researchers as a photocathode material in PEC cell. Cu2O has many advantages such as its proper band gap (~2 eV) for the absorption of visible light, favourable conduction band position (~0.7 V negative of hydrogen evolution potential) etc. But, Cu2O is known to undergo photo-corrosion, when used as a photocathode in the PEC cell. Therefore, many researchers have developed methods to stabilize Cu2O by coating other stable materials on its surface. In this context it becomes very important to stabilize the Cu2O itself. It is a well known fact that, the catalytic or electrochemical properties of semiconducting materials vary depending on which crystal facet has been exposed at the interface, because of the different atomic arrangement of each crystal facet(s) and the corresponding surface electronic structure. In the photocatalytic context of Cu2O, the (111) facet is considered as most stable. We have thus grown single crystalline Cu2O nanoneedles with (111) exposed facets, directly on copper foil and the same film is used as photocathode for photo-electrochemical water splitting. It shows excellent performance as reflected by the current density of ~1.7 mA/cm2 photocurrent at 0V vs. RHE in 50 mM Na2SO4 having pH ~6.5. This performance shows ~40% stability upto 1 hr of exposure to light. These interesting set of data will be presented and discussed.

ABSTRACT. Titanium dioxide nanorods were successfully synthesized by hydrothermal process at 170 °C. The structural and crystallographic information of prepared samples was confirmed with Powder X-ray diffraction analysis, which shows larger fraction of anatase phase with small fraction of brookite phase. The morphological results show that the TiO2 nanorods had diameter of about ~ 25 nm and the length of ~ 100 nm which is confirmed with field emission scanning electron microscopy. From the nitrogen adsorption and desorption isotherm analysis, the specific surface area and pore volume of the synthesized material have been calculated with the help of Brunauer-Emmett-Teller and Barrett-Joyner-Halenda approaches (BET surface area: 84.83 m2/g and Pore Volume: 0.1316 cc/g). The synthesized nanorods have been used to fabricate the dye sensitized solar cells and its performance was analyzed with the help of current-voltage characteristics with standard light source. The solar energy conversion efficiency (η) of the DSSC was about 2.15 % with short circuit current of 5.97 mA/cm2, open circuit voltage of 0.63 V and fill factor of 0.57 %.

ABSTRACT. Thermal barrier coatings play a vital role to make the engine more adiabatic. This concept of improving the combustion capacity, better diffusion, atomization and lubrication have generated impetus to active research on low heat rejection (LHR) or insulated engines. So with this aim, this study presents concept of thermal barrier ceramic coating in internal Combustion engines. The engine was thermally insulated by coating at such as piston-head with TAFA95MXC material having 250 μm thickness and various nozzle geometries. Experimental tests were done at 0, 20, 40, 60, 80, 100% load at 210 bar injection pressure and 25°BTDC injection timmings. Results shows that, in modified engine (coated parts & 3 hole nozzle) brake thermal efficiency increased by 2.12% , fuel consumption decreased about 6.48%, exhaust gas temperature increased up to 11.42 %, CO emissions reduced by 14.28%, CO2 increased by 11.43%, HC reduced by 2.12% and NOx increased by 8.43 % as compared to unmodified (original) conditions.

ABSTRACT. Present study reports fully developed laminar flow convective heat transfer and friction factor characteristics of MWCNT/water nanofluid(φ=0.15%) flowing through a uniformly heated horizontal tube with and without wire coil The stable nanofluid was prepared by dispersing CNTs of diameter 10 nm in distilled water. The experiments using the plain tube and with wire coil inserts were also carried out with distilled water as the working fluid for experimental setup validation and comparison. The experimental results reveal that the use of nanofluids increases the heat transfer rate with negligible increase in friction factor in the plain tube and the tube fitted with wire coil inserts. In addition, empirical correlations are proposed based on the experimental results of the present study, which are found to be sufficiently accurate for prediction of the heat transfer and friction factor characteristics.

ABSTRACT. In Electric Vehicle applications, the role of induction motor (IM) is important remarkably with respect to the efficient energy consumption. Though the IMs are rugged and cost effective, yet their low speed operation is not much satisfactory. This paper proposes a new sensorless speed control technique for IM using a noble model reference adaptive controller (MRAC) with a basic efficiency optimization technique known as golden section method. The proposed MRAC for the vector controlled IM drives by utilizes instantaneous and steady state values of a fictitious resistance (R) in the reference and adaptive models respectively. The proposed scheme is immune to the variation in stator resistance (Rs). Moreover, the unique formation of the MRAC with the instantaneous and steady-state reactive power completely eliminates the requirement of any flux estimation in the process of computation. Thus, the method is insensitive to integrator-related problems like drift and saturation enabling the estimation at or near zero speed quite accurate. The proposed drive’s performance with the R-MRAC is validated for various speed ranges and patterns in Matlab/simulink. Sensitivity of various motor parameters and stability studies are carried out using eigenvalues loci plots by first order eigenvalue sensitivity analysis.

ABSTRACT. In this presented work, geometric parameters like chord length and twist angle of the blade, and aerodynamic forces are optimized using MATLAB programming. The basic airfoil shape has been taken as NACA 63-415. The optimization has been done using classical blade element momentum theory with the aid of the Prandtls tip loss correction factor. The optimized design was then imported and modeled in Pro/ENGINEER. This optimal design, the dynamic simulations have been carried out by ADAMS software to measure the torque characteristics. The torque performance data of ADAMS simulation has been compared with 3D unsteady simulation using CFD software ANSYS/Fluent at a wind speed of 10 m/s. The flow properties around the 3D solid model of the wind turbine rotor have also been analyzed in ANSYS/Fluent. The performance and flow properties have been analyzed at the rotating condition. The SST k-ω turbulence model is implemented to solve the RANS equations. The turbine performances are analyzed in respect of average torque and power coefficient. The results obtained from both ADAMS and ANSYS/Fluent seems to be quite encouraging as the percentage error is found negligible. Furthermore, the various flow patterns analysis around these turbines is carried out in terms of velocity magnitude counter and pressure counter.

ABSTRACT. A high performance offline genetic algorithm based three phase boost inverter has been proposed in this work. The digital PI controller makes use of the offline genetic algorithm to improve the performance of the three phase boost inverter. The offline genetic algorithm is used to improve the dynamic response and decrease the content of total harmonic distortion in the three phase boost inverter. The genetic algorithm decreases the effect of the parameters such as rise time, settling time, peak overshoot and steady state error which influence the dynamic response of the system. The overall system efficiency and reliability is shown to be enhanced due to the offline genetic algorithm. The content of total harmonic distortion is also shown to be decreased due to the proposed offline genetic algorithm.

ABSTRACT. This paper presents an intelligent diagnosis technique for wind turbine imbalance fault identification based on generator current signals. For this aim, Support Vector (SVM), which is powerful algorithm for classification problems that needs small training time in solving nonlinear problems and applicable to high dimension applications, is employed. The complete dynamics of a permanent magnet synchronous generator (PMSG) based wind-turbine (WTG) model are imitated in an amalgamated domain of Simulink, FAST and TurbSim under six distinct conditions, i.e., aerodynamic asymmetry, rotor furl imbalance, tail furl imbalance, blade imbalance, nacelle-yaw imbalance and normal operating scenarios. The simulation results in time domain of the PMSG stator current are decomposed into the Intrinsic Mode Frequency (IMF) using EMD method, which are utilized as input variable in SVM. The analyzed results proclaim the effectiveness of the proposed approach to identify the healthy condition from imbalance faults in WTG. The presented work renders initial results that are helpful for online condition monitoring and health assessment of WTG.

ABSTRACT. In the presented work we describe a Convolutional Neural Network (CNN) to accurately identify healthy and imbalance faulty condition of wind turbine generator system (WTGs) without using mechanical sensors. The complete dynamics of a WTGs model are simulated in a combine domain of Simulink, FAST and TurbSim under two different conditions, i.e., healthy and faulty condition. Simulated results in time-domain of generator current signals of direct-drive wind turbine are decomposed into the Intrinsic Mode Frequency (IMF) using Empirical Mode Decomposition (EMD) method, which are utilized as input variable in CNN after selection of most relevant input variable by RapidMiner based principle component analysis (PCA) algorithm. The analyzed results proclaim the effectiveness of the proposed CNN approach to identify the operating condition of WTGs. Further experiments on WTGs with more imbalance faults demonstrate the operational condition estimation ability of our CNN model, which is rarely reported in previous literature.

ABSTRACT. Dynamic soaring is the rationale behind the prolonged flights of a seabird Albatross. By dynamic soaring, small unmanned aerial vehicles (UAVs) can be kept loitering without any external power input. In this work, dynamic soaring is used to power UAVs for the surveillance application. Dynamic soaring involves utilization of energy from the wind shear present near the earth surface. 6-DoF point mass equations governing the aircraft motion are used in the problem formulation. Trajectories of UAV are optimized by using an optimal control software GPOPS-II. Variation in the area under surveillance is analyzed with the change in the view angle of camera, wind strength, and the nature of wind shear profile. Minimum requirement of wind strength for performing dynamic soaring, considering various wind shear profiles has been identified. Finally, it is concluded that small UAVs (comparable with the size of Albatross) can be constantly kept on surveying using wind energy as the sole power source, as long as the wind shear coefficient is greater than the minimum requirement for dynamic soaring.

ABSTRACT. In the present study the summary of offshore wind resources of the India has been provided by analyzing the OSCAT satellite data measured over 2 years (2012-2013). In order to calculate the offshore wind potential at the selected locations, the Geographical Information System (GIS) is used to generate winds at the turbine hub height of 80 m and to determine the suitability of the area regarding the wind energy development. The calculation shows that maximum range of average wind speed and wind power density are 9.7-13.4 m/s and 1048.7-1632.5 W/m2 respectively, followed by extraction of generated power using a modern wind turbine.

ABSTRACT. The Distributed Power Generation (DPG) at low /medium voltage demands that the renewable generation system is always grid connected during fault condition to ensure the stability of wind power system. The DPG consisting of Wind Turbines (WT) along with Fixed Speed Induction Generator (FSIG) does not provide accurate reactive power control and hence there is need for dedicated compensation. Due to fault condition the negative sequence component is affected and hence there is direct impact on DPG with reduction in life expectancy. This paper proposes the application of Distributed Static Compensator (DSTATCOM) for Fault Ride through (FRT) and reactive power compensation. It has been observed that the compensation of negative sequence component improves the performance of FSIG based WT. Also the compensation of positive sequence component avoids the collapsing of voltage and improved the stability of WT. The simulation is done in MATLAB and various tests are considered under fault condition in which results are presented. The FRT enhancement of grid connected WT by using DSTATCOM is 30% and hence 30% additional wind power is penetrated to the grid. Distributed power generation, Reactive Power, Distributed Static Compensator i.e. DSTATCOM, Indirect Current Control Scheme.

ABSTRACT. This paper presents an intelligent diagnosis technique for wind turbine imbalance fault identification based on generator current signals. For this aim, Proximal Support Vector (PSVM), which is powerful algorithm for classification problems that needs small training time in solving nonlinear problems and applicable to high dimension applications, is employed. The complete dynamics of a permanent magnet synchronous generator (PMSG) based wind-turbine (WTG) model are imitated in an amalgamated domain of Simulink, FAST and TurbSim under six distinct conditions, i.e., aerodynamic asymmetry, rotor furl imbalance, tail furl imbalance, blade imbalance, nacelle-yaw imbalance and normal operating scenarios. The simulation results in time domain of the PMSG stator current are decomposed into the Intrinsic Mode Frequency (IMF) using EMD method, which are utilized as input variable in PSVM. The analyzed results proclaim the effectiveness of the proposed approach to identify the healthy condition from imbalance faults in WTG. The presented work renders initial results that are helpful for online condition monitoring and health assessment of WTG.

ABSTRACT. The volume changes that are associated with composition changes in a solid can induce significant stresses, when these expansions or contractions are physically constrained. These phenomena are important in a variety of energy-related materials, where they can lead to complex interactions between electrochemical and mechanical driving forces. We have employed a variety of in situ and ex situ measurements to obtain critical information about how the relevant mechanisms operate in different types of materials. In Li ion battery electrodes, Li insertion and removal can lead to very large stresses and complex deformation behavior. One area of interest here is the solid-electrolyte interphase (SEI) layer, where we have shown that stresses and SEI mechanical properties can be engineered to enhance the stability of these critical passivation layers. Results for several other mechanics-related phenomena will be presented, including the influence of compositional stresses on phase transformations in battery cathode materials, and interface adhesion in systems with solid electrolytes. 

ABSTRACT. Herein, we report a facile, low-cost and one-step electrodeposition approach for the synthesis NiCo2S4 (NCS)) nanosheet arrays on Ni foam. The morphology of the materials are characterized by energy dispersive x-ray analysis and field-emission scanning electron microscopy. The supercapacitor performance of the NCS nanosheets are studied in three electrode configuration in 2M KOH electrolyte. The as-prepared binder free electrode shows a high specific capacitance of 1500 F/g at 3 A/g with excellent cyclic stability even after 1000 charge/discharge cycles. Obtained energy density and power density of the MCO nanosheets are 50.58 Wh/Kg and 12.978 Kw/Kg respectively. The superior electrochemical performances are mainly attributed to its nanosheet like structure which provides large reaction surface area, fast ion and electron transfer rate.

ABSTRACT. Alluaudite-type sulphate framework Na2Fe2(SO4)3 is gathering attention because of its highest-ever Fe3+/Fe2+ redox potential at 3.8 V (versus Na) along with fast rate kinetics and excellent cycling stability (Nat. Commun., 5, 4358, 2014). Reported synthesis is a careful solid-state method involving (a) formation of anhydrous FeSO4 from commercial FeSO4.7H2O, (b) prolonged milling and (c) longer annealing (350°C, 24 h). Journey of such materials from laboratory to industry warrants economic, sustainable and scalable synthesis. Here, we report novel solution assisted- ionothermal, aqueous spray-drying and pechini synthesis of Na2Fe2(SO4)3, [M = 3d metals] alluaudite cathodes. It describes the (i) salient features of various synthesis, (ii) structure/ polymorphism, (iii) magnetic properties and (iv) electrochemical properties of Na2Fe2(SO4)3 cathode materials.

ABSTRACT. The demand of rechargeable Lithium ion batteries are increasing drastically in systems such as electric vehicles, space and aircraft power system and stationary power storage due to their stability, long life time and moderate energy density. To increase the energy density and stability to greater extent, we are in search of materials with low-cost, environmental friendly, more cycle life and low operational voltage. Even though sp2 hybridized graphitic carbons are using as an anode materials in commercial LIBs, which has theoretical capacity of 372 mAhg−1 with stoichiometry of LiC6 [1-2]. In addition, the sp2 hybridized bonds provide good structural integrity, which is essential for anode materials. The adsorption of lithium ion on both sides of the graphene sheets produced maximum theoretical capacity of 744 mAhg-1 with the formation of Li2C6 [3]. However, when Li intercalates between the sheets of carbon atom, its volume expansion occurs by 10%. We need complete understanding of adsorption and diffusion of Lithium atom in carbonaceous materials due to their complexity of bulk transport properties in finite-sized, non-isotropic particles. To solve this problem we use density functional theory (DFT) based calculations to quantify adsorption and diffusion mechanism of lithium-ion in our system. We report the band structure and density of states of the 3D metallic T6 Carbon with a high symmetric space group (P42/mmc) and found it to be metallic due to sp2 hybridized carbon atoms [4]. We consider the thin film of T6 carbon along the (100) and (001) plane for the understanding of adsorption and diffusion of Li atom. Among the absorption sites in the T6 (100) structure, the result shows that the Centre-Hollow (C-H) and Centre-Bridge (C-B) sites are the most favourable sites with binding energy of 1.2 eV and 1.23eV respectively. The NEB calculation showed that the diffusion of Li over the basal plane is easy with very low activation barriers [5]. We found that the T6 (100) structure can be considered as promising anode material with better capacity and also exhibit good diffusion kinetics for Li atom. Reference: [1] J.-M. Tarascon and M. Armand, Nature, 2001, 414, 359–367. [2] Y. Nishi, J. Power Sources, 2001, 100, 101–106. [3] K. S. Novoselov, A. K. Geim, S. V. Morozov, Y. Zhang, S. V. Dubonos, Science ,2004,306, 666–669. [4]Shunhong Zhang, Qian Wang, Xiaoshuang Chen, and Puru Jenab, PNAS, 2013, 110, 18809-18813.

[5]Rahul P.Hardikar, Deya Das, Sang Soo Han, Kwang-Ryeol Lee and Abhishek K.Singh, Phys.Chem.Chem.Phys. 2014, 16, 16502.

ABSTRACT. For lithium and manganese rich oxide cathode materials we have found that (i) a significant structural change occurs during first cycle, (ii) a relatively slower and continuous structural change occurs during repeated cycling and (iii) an electronically insulating solid electrolyte interface layer grows with repeated charge-discharge cycling. All these factors significantly influence the electrochemical performance of the cathode material. Various approaches have been adopted to improve the electrochemical performances of the nano-composite xLi₂MnO₃-(1-x)Li(Mn_0.375Ni_0.375Co_0.25)O₂ (0.0 £ x £ 1.0) cathode materials. First, the composition of the composite cathode and process parameters are optimized to yield high discharge capacity. Thus a discharge capacity of ~300 mAhg^-1 is obtained in x=0.5 cathode. A layered to spinel conversion is identified in cathodes with higher Li₂MnO₃ content. Second, we have demonstrated that the porous particulate ZrO₂ coating improved the capacity retention of these composite cathodes by suppressing the impedance growth at the electrodes-electrolyte interface. Finally, we have demonstrated that among several interrelated factors (viz. cathode composition, activation of Li₂MnO₃ component, crystallinity of the cathode particles etc.) an optimum particle size is very much crucial for the improved performance of the synthesized cathode materials.

ABSTRACT. In the present study, energy and exergy analysis of Organic Rankine Cycle (ORC) powered vapor compression-absorption cascade refrigeration system has been performed. The thermodynamic model consist of mass,energy and entropy balance has been developed for each component of the system. Operating parameters (temperature, pressure and mass flow rate) and calculated flow parameters (enthalpy, entropy and exergy) are determined at inlet and outlet of each points. Detailed first and second law analysis using various performance parameters (Coefficient of performance, exergetic efficiency, irreversibility of the system component, total irreversibility of system and improvement potential) and parametric study is under process and the same will be submitted in the final manuscript.

ABSTRACT. In the present work, an Earth Water Heat Exchanger (EWHE) has been designed for Pilani, Rajasthan (India). The system is designed and simulated in transient analysis tool TRNSYS (v17.0) by varying its operating parameters which includes mass flow rate, length, pipe materials and diameter of buried pipe. The depth-wise temperature of soil has also been evaluated from the simulation and it is found that the depth of 3.5 m is sufficient for pipe burial. The results show that there is an inverse correlation between the pipe length and the EWHE outlet temperature. The comparative study between three different material shows that the performance of EWHE system hardly depends on the properties of these material. Further, the EWHE performance is found to be decreasing with an increase in the mass flow rate from 0.008 kg/s to 0.05 kg/s. The simulated proposed system is then compared with the existing ones in the literature for a given cooling setup of Concentrating Photovoltaic (CPV). It is observed that the proposed system gives better performance than the cooling system given in literature. To achieve the temperature drop from 48.5 °C to 25.5 °C as per the existing CPV setup in the literature, the pipe length of 60 m would be sufficient in the proposed EWHE system. Thus the coupling of EWHE with CPV plants could be economical as well as performance enhancer.

ABSTRACT. Bangladesh is a country endowed with an abundance of natural resources, notable of which would be of the marine variety. Modern research in utilizing marine energy started in 1973 and one of the first product of the research was the Salter’s Duck, which was an inspiration for further developments despite it’s ineffectiveness in practice. Marine energy is not yet a viable option of providing large-scale energy, but it has been estimated that 10% of the world’s energy requirement can be fulfilled if the sites suitable for implementation of the systems are properly developed. Utilization of marine energy is still just a theoretical concept in Bangladesh, and the most comprehensive work done on the field was on the possibility of using Pelamis Wave energy converter The objective of the study is to convert & utilize marine energy of Bangladesh in an effective way based on data collection, analysis & scientific research.

1.Electricity Production: • A Data well directional wave rider buoy is used to measure the wave spectral Parameters that are required for planning marine operations and the design of marine structures in Bay of Bengal. • Variations in wave spectral characteristics of waves of Bay of Bengal over a period are observed using a moored directional wave rider buoy. • Significant wave height and mean wave period are estimated from the spectral moment.

• A power buoy system is used to generate power through the ocean wave. The Power -Buoy system works by having a buoy tethered to the ocean floor. As the waves come in, the part of the buoy that floats works as a piston against the tethered portion, generating mechanical-electric power.

• Linear generator is used in which there is a magnetic shaft surrounded by an electric coil inside the buoy. • With the motion of the waves, the coil moves up and down, voltage is Induced in the magnetic shaft and electricity is generated • Wave energy converters (base units) are connected in larger arrays ranging from tenths up to thousands of individual converters in the plant at last.

2.Development of Fish-Culture in Marine Environment: The study gives a priority in developing the methods of fish-culture giving importance on the following things: • Developing high quality fish protein by isolating collagen, gelatin and fish oil . • Designing a simple and cheap extruder for and built in Bangladesh • High quality and nutritious and dried food products including infant foods, snacks are needed to make from the selected fish. • Biochemical changes (protein de nitration and lipid oxidation) in dried and extruded fish food products are needed to investigate for improved quality control methods and preservation systems, including natural antioxidant mixtures.

1. Power Buoy with peak-rated power can give output of 150 kW 2.In moderate ocean swells, in deep water, a few km off a coastline, with a wave height of 3 m and a wave energy period of 8 seconds,36 kilowatts of power potential per meter of wave crest will generate. 3.In major storms, the largest waves offshore are about 15 meters high and have a period of about 15 seconds will produce 1.7 MW of power across each metre of wave front based on Wave energy flux formula.

Uniqueness of marine resource energy & resource utilization:

1. The energy is free 2. Fuel is not needed, and there is no waste produced 3. Not expensive to operate and maintain. 4. Can produce a great deal of energy 5. Development of Marine fish-culture will expand post harvest fish processing technologies to produce nutritious, safe and cheap products for local use 6. It will serve as a purpose of aiding food security.

The study would serve as a scope for marine energy & resource utilization as well as creating an alternate option for emergency power during a national power failure. Again the improvement of fish culture would develop strong and beneficial long-term link between developing countries like Bangladesh and Europe in terms of research, education and training and trade.

ABSTRACT. Solid waste disposal problem is a growing concern of today’s world. It is creating serious health hazards and environmental issues need to be tackled on urgent basis. Developing economy like India is also facing the problem due to the rapid industrialization, population growth and changing lifestyle. In India, municipal solid waste (MSW) disposal problem is a serious concern as it creates potential environmental hazards, health problems etc. Like other parts of the country, we have noticed that in Pune City also, per capita waste generation is growing steadily mainly due to the changed lifestyle. The increased volume of waste generation in last 10 years has created stress on all the natural and infrastructural resources. If this waste be suitably utilized for energy production instead of incineration or burring in the dumping ground, the energy crisis can be reduced with the simultaneous reduction in environmental pollution. This waste can be gasified directly or can be converted into Biogas through the microbial processes. Gasification Technology is an efficient one as most of the solid wastes can be gasified directly to produce synthesis gas or producer gas. The gas obtained can further be utilized to generate electricity or can be used directly as a fuel even it can be utilized to produce plethora of various petrochemical products. We have conducted a simulation study on a downdraft gasifier to highlight its potential in MSW disposal problem for Pune city

ABSTRACT. Smart grid is characterized by a two way flow of electricity and information and capable of monitoring load supply and demand from utility to the end users on real time basis. This kind of system helps the utility to do better load management. This work is focused on establishment of a Smart Micro Grid at Solar Energy Centre which integrates the conventional energy sources and renewable energy sources through a centralized controller. This system tries to manage the energy generation and demand through wireless communication technology between generation and demand and supports for energy saving. The real time monitoring of generation from renewable energy sources and demand side management has been done through IEMU. It is observed that there is an improvement of energy generation from renewable energy sources through immediate attention to the faults. It has been found that continuous monitoring of the photovoltaic plant, there has been an average increase in energy generation in the order of 30% per day. The smart management not only save energy but also manage to utilize renewable energy at a maximum level and helps in better load management at the end users point.

ABSTRACT. Adsorption kinetics of Carbon dioxide (CO2) on activated carbon (Norit type RB3 steam activated rod) and zeolite 5A are compared at different temperatures (298 K, 318 K, 338 K and 358 K) and pressures (1 bar, 5 bar, 10 bar and 20 bar). Sievert’s type experimental setup is used for adsorption kinetics measurement. The experimental data on activated carbon and zeolite 5A are subsequently modelled using a pseudo first and second order kinetics model, which revealed that the pseudo second order model well described the CO2 adsorption kinetics data than pseudo first order model. The rate constants and activation energies of CO2 adsorption on the adsorbents are estimated. It is found that at very low pressure the rate of CO2 adsorbed on zeolite 5A is more than that of the activated carbon, while at higher pressure, the rate of CO2 adsorbed on the activated carbon is higher than the zeolite 5A due to large surface area and pore volume. Activation energies on activated carbon and zeolite 5A are calculated at different pressures by fitting the Arrhenius equation to the adsorption kinetics data. It is observed that the activation energies of zeolite 5A are slightly higher than that of the activated carbon.

ABSTRACT. Hydrogen as an energy carrier, and fuel cells as energy conversion devices have gained traction recently in the context of the shift toward more efficient and less carbon-intensive energy solutions. This has renewed the interest in delocalized hydrogen generation with a lot of focus on hydrocarbon reforming process, in particular autothermal reforming due to it's thermodynamic neutral nature and relatively high yield. Reforming bio-fuels like ethanol has an added advantage of being renewably available and being carbon neutral. However, the focus of research in the past few years has been catalyst development and the evaluation of the process and equipment with little work being done on the numerical modeling, kinetics and mechanism of the reaction. This is primarily due to the computational complexity involved in solving detailed microkinetic mechanisms that elucidate the working of the catalyst system using surface reactions and capture the reactor performance over a wide range of reactor conditions.

Hence it becomes essential to hierarchically reduce the detailed microkinetic mechanism to mechanisms that include only the major pathways of reforming. However, to perform such a reduction it is essential to understand the major steps in the process, and also to take into account the variation in these pathways with changing co-reactants concentrations and reaction temperatures. In this paper, we have adopted a microkinetic mechanism from literature consisting of 14 gas phase species, 48 surface species and 196 surface reactions and conducted detailed studies on the mechanism to determine the chief pathways for autothermal reforming.

ABSTRACT. Two level inverters generate Common Mode Voltage (CMV). CMV causes high frequency common mode electromagnetic interference (EMI) noise. This CMV also causes leakage current in grid tied inverter and bearing currents in electrical drives application. So, reducing the CMV within the power converter has become important. CMV can be reduced either by using additional hardware, such as EMI filters or by investigating the modulation technique or by using both. As CMV is generated due to asymmetrical operation of switching pulses, so this can be inferred that CMV is mainly depend upon the PWM strategy used in the inverter. Using suitable PWM, mitigation of the CMV and thereby EMC is achievable within the inverter. In this paper we will be making a comparison between the different Pulse Width Modulation (PWM) techniques employed for three phase voltage source inverters (VSI).According to IEC, 2011, maximum allowable leakage current is 300mA. The CMC can be reduced by applying best suited modulation strategy to the inverter and this CMC can be further reduced by employing common mode choke (in this case, EMI filter). In this project, EMI filters are employed in 2 level grid tied inverter and CMV and common mode current (CMC) is mitigated to great extent. Also, various PWM techniques are also implemented in order to observe any further change in the common mode voltage and current.

ABSTRACT. In this paper the theoretical and experimental studies were carried out on a direct expansion solar assisted heat pump (DX-SAHP) under the metrological condition of Calicut located in the southern peninsula of the India continent. The system mainly includes a flat-plate solar collector of total are 2 m2, acting as an evaporator with refrigerant R22, a hermetically sealed reciprocating type compressor, an air cooled condenser and an electronic expansion valve. These performance parameters such as energy performance ratio, power consumption, heating capacity, solar energy input ratio and compressor discharge temperature of a DX-SAHP obtained from the experiment confirmed that, the experimental values were agreed well with simulation predicated results with average error of 1-2%. And The system COP is found to be vary from 1.8 to 2.8, power consumption from 1098 to 1305W, heating capacity from 2.0 to 3.6 kW respectively. The effect of various parameters such as solar insolation, ambient temperature, collector area, wind speed has been theoretically analysed in order to understand the system performance.

ABSTRACT. In present scenario it is need for automobile sector to develop clean technology which will result in less fuel consumption and green house gas. Premixed Charge Compression Ignition (PCCI) is one of the effective technologies that give efficiency close to conventional CI engine and eliminates generation of high NOx and PM simultaneously. NOx formation is mainly temperature dependent phenomenon and it occurs when the temperature in the combustion chamber exceeds 2000 K. Hence in order to reduce NOx emission it is essential to keep peak combustion temperature under control. In the present investigation an external mixture formation technique is used to achieve PCCI operation. For this purpose a device known as diesel vaporizer is designed and fabricated. The port fuel injector operates at 3 bar injection pressure is used to inject the fuel into the heated vaporizer where it vaporizes and mixes with air in the intake port to form a premixed charge. To control auto ignition of diesel vapor and air mixture, exhaust gas recirculation (EGR) technique is used. In the present investigation 10%, 20% and 30% EGR is used for PCCI mode of operation and the results were compared with conventional CI mode of operation.

ABSTRACT. - Exergy analysis method has been widely used in the design simulation and performance assessment of various types of engine for identifying losses and efficiencies. This study deals with investigating the effect of load level and EGR temperature on overall exergy of diesel engine. In this investigation, the energy and exergy analysis are employed to analyze the quantity and quality of energy in 4-stroke single cylinder direct injection diesel engine using diesel as fuel. The experiments has done at four constant speed (1500, 1800, 2100 and 2400 rpm) and load level (0,2,4,6,8,10 & 12 ). Effect of EGR temperature on the various exergy terms has also investigated. The experimental data are collected using steady state tests which enable measurements of air, fuel flow rates and relevant temperatures. Balances of energy and exergy rates for the engine are determined and various performance paramters (loss exergy, exergy accompanying due to heat, exhaust exergy, brake thermal efficiency etc.,) are calculated for each load level and compared with each other. The parameters analyzed are the energy and exergy of fuel input, exhaust gas and exergy destruction, fuel chemical exergy. Side by side, the effect of the variation of load and EGR temperature on peak pressure, heat release rate,, exergy efficieny, various exergy temrsand entropy generation are also discussed.

ABSTRACT. This article is concerned with the performance of natural convection and a rotating fluidized bed in a static geometry (RFB-SG) dryer for drying of paddy. The experiments were in batch drying. The drying vortex chamber diameter has 24 cm and length 5 cm. The experiments were conducted on drying of paddy with 4.95 mm length, 3.0 mm diameter with density of 1111 kg/m3. The inlet drying air temperature was 50, 55, 60 and 650C with air mass flow rate 400,500, 600 and 700Nm3/h. The inventory of paddy for drying was 300, 400, 500 and 600g. The performance with respect to drying rate, product uniformity and process intensification was evaluated. In case of RFB-SG dryer, drying process intensified, drying time less, more quantity of paddy dried in less time and uniformity, quality of the drying particle were maintained. The drying of paddy in a natural convection dryer was 0.03 kg/m3.s in compare to RFB-SG dryer was 0.8 kg/m3.s. The process intensification (PI) factor was 24 to 27 in RFB-SG dryer. The cost in terms of increased and less efficient air utilization can be minimized by optimized the RFB-SG drying chamber design.

ABSTRACT. Energy harvesting from rainwater through various smart materials have come into research, thus widening the scope of using these materials for the implementation and the considerable growth of energy harvesting techniques is essential. The piezoelectric materials present a brief idea of voltage generation whenever the material is strained or deformed. The purpose of our study is to carry out the parametric analysis and comparative study of piezoelectric effect based energy harvester using two different commercially available piezoelectric materials viz. PZT-4A and PZT-5H, through series of implicit and explicit method simulations of FEM on COMSOL and ANSYS, along with variation in the rainwater droplet size viz. 1.6mm, 3mm and 5mm. Firstly, the dynamic loads of different rainwater droplets sizes are investigated analytically. To calculate the variation of different methods in terms of deflection and voltage output, the implicit and multibody explicit dynamic simulations are implemented separately.

ABSTRACT. Due to increasing in consumption of fuels and their day by day , let the search of alternative fuels are gaining importance . Biofuels or biodiesel are the common alternatives to overcome our demands. They should be way of producing max yield , with alcohol recovery with less impurities or glycerol removal.. The commonly known way to produce biodiesel is transesterification there are many ways for purifiying the produced biodiesel , generally hot water washing is done for removal of glycerols, in some methods acetic acid is used with washing , now there is a another method name three step transesterification in which absorbents are used for complete washing. In this work ludox is used as dessicator , absorbent for removal of glycerin from biodiesel and evaluate the effectiveness of biodiesel purity . For the achievement of best yield , various parameters are compared using different amt of acid and base catalyst , reaction time and temperature , different alcohol ratio and different types of alcohol . The best yield of KOME was 98 % obtained using naoh and H3PO4 as catalyst with methanol ,alcohol to oil ratio of 3:1 in 90 min at 70oc

ABSTRACT. Anaerobic fermentation using mixed cultures has emerged as a cost effective and sustainable method to produce hydrogen. The pretreatment of wastewater sludge by five methods such as heat, acid, base, microwave and chloroform was conducted and compared for hydrogen production. The highest hydrogen production across the pretreatment methods for heat treatment was around 15.18 ±0.26 mmol/L of medium at 30 ºC using 1% crude glycerol as substrate. The heat pretreated inoculum possessed better natural acclimatization activity for degrading CG and produced twice as much as hydrogen in comparison to other pretreatment methods. Based on the results, heat treatment at 100 ºC for 15 min was selected for central composite design (CCD) along with response surface methodology (RSM) was used as tool for optimization. The fermentation condition such as crude glycerol (CG) concentration (2.5 to 25 g/L), percentage of inoculum size (InS) (2.5to 15 % v/v) along with initial pH (3 to 7) was tested with hydrogen production as response parameters. The optimum conditions at 20 g/L of CG, 20% InS and at pH 7, resulted in maximum hydrogen production of 28.72 ±0.71 mmol/L. The increase in concentration of crude glycerol with increasing inoculum size increased hydrogen production, however the effect of initial pH was dominant and had a significant effect (p-value: 0.0011) in increasing hydrogen production. The mixed-culture survived the potential inhibitors compounds present at 20 g/L of CG and overcome the substrate inhibiting concentration of pure and co-culture system to produce maximum hydrogen production 28.72 ±0.71 mmol/L.

ABSTRACT. The present study discusses the performance of the electric two-wheeled vehicles on the basis of their running conditions in present day traffic in the urban regions. In this study survey based results and experimental outcomes were compared with that of the conventional IC engine counterpart for the road conditions in the city of Kolkata. The specific energy consumption of the electric variants were found to be 155.64 kJ/km and 114.5 kJ/km from the experimental and survey results, respectively, compared to 810 kJ/km of the conventional two-wheelers. The specific energy cost and the specific CO2 emission were also obtained from the study.

ABSTRACT. In this work, an integrated system of electrolyzer with CI engine which introduces HHO gas into the air intake is experimented. The system was installed to the engine with all the accessories including the required safety measures. The experiments were conducted on a 553cc single cylinder constant speed (Kirloskar) engine. Dry cell HHO generator has been installed to the test engine. The test gave the result such that the fuel consumption has been reduced by 6- 12% with an HHO gas supply of 1LPM along with the engine air intake

ABSTRACT. This paper presents a review on different roof technologies performed with an aim to reduce the cooling loads during summer thus helping in energy conservation. Firstly it deals with green vegetated roof carried out in regions of hot humid climates. The green roof performance was explored by evaluating its effect on temperature fluctuations and heat fluxes during summer. The results showed that the presence of plants led to a decrease in temperature under the green roof. The water use and tolerance to stress at times of prolonged drought were also assessed for several types of plants suitable for extensive green roof systems. Other cooling strategies are use of reflective paints also called cool paints. The impact of the application of a reflective paint on a flat roof were analyzed by mainly monitoring reduction of roof surface temperature at different case study locations. Further performance of three kinds of cool paints and even cool black paints are studied for going deeper into the facts of cool paint potentials and limitations. Eventually a comparative analysis between these two solutions are assessed by taking into account the several parameters that affect the final energy performances.

ABSTRACT. The depletion of fossil fuel resources on a worldwide basis has necessitated an urgent search for alternative energy sources to meet up the present day demands. Solar energy is clean, inexhaustible and environment-friendly potential resource among renewable energy options. But neither a standalone solar photovoltaic system nor a wind energy system can provide a continuous supply of energy due to seasonal and periodic variations. Therefore, in order to satisfy the load demand, grid connected energy systems are now becomes promising options that combine solar and conventional energy systems to meet the future energy demand at reduces consumption of fossil fuels. In the present work it is tried to develop a small scale grid connected solar photovoltaic (SPV) system. The details of the grid connected solar photovoltaic system are studied first. Here in this present work 1 kWp SPV system is considered for system design. Then it is installed on the roof top of our School of Energy Studies Building and successfully connected with the grid. We find that the system is feeding power to the grid successfully. As the installation was completed in few days back the details performance result could not be included now. But we found that the preliminary results are promising. On a sunny day noon it is generating around 750 Watt which may ensures the feasibility of these kind small system connected with the grid. And it will help to reduce the electricity bill for the consumers who have maximum consumption in day hours i.e. School, College, Office, Commercial buildings, Shops etc. Now we are ensuring that hopefully the detailed performance results of the same will be included in the full paper and be presented in the conference. To best of our Knowledge this is the first time such type of small scale grid connected solar photo voltaic (SPV) system was reported.

ABSTRACT. A natural convection V-groove solar dryer has been fabricated with locally available material and tested for drying of two different thickness potato slices under the meteorological conditions of Bhubaneswar, Odisha, India. The System consists of a V-grooved aluminum absorber plate, glass, insulation material and a drying chamber. Paraffin wax grade –II used as a thermal energy storage material to store excess energy and supply during off shine hours and cloudy condition during drying. The solar air heater was tilted about an angle of 20° horizontal. The set up is oriented to face south to maximize the solar radiation incident on the solar collector. The experiments were carried out in day time from morning 9.00 AM to evening 8.00 PM. Experiments were conducted to dry the two different thicknesses of the potato slices of 8 mm and 4mm .The experiments were performed for drying of 2 kg of potato slices as in a single batch. The time taken for drying of potato slices thickness of 4 mm was 600 min and similarly for drying of 8 mm thickness potato slices was 780min respectively from initial moisture content of 84% to 11 %.

ABSTRACT. In an air-conditioned building located at any climatic region, the energy usage could be conserved by means of reducing the heating or cooling load on the Heating, Ventilation and Air Conditioning (HVAC) system depending upon outdoor climatic conditions. In case of unconditioned building, the temperature variation inside it over a specified time depending upon the outdoor climatic conditions helps one to estimate the duration of uncomfortable periods. By controlling heat gain or loss through building components like walls, roofs, window glazing etc. the overall energy used in both types of buildings could be minimised and for doing so, thermal performance of any building material should be evaluated. The overall heat transfer coefficient, which is measured using the Guarded Hot Box Test Facility, is one of the key measures of evaluating the energy performance of any building material. The lesser this value, the less energy is required to maintain comfortable conditions inside the building. In this paper, the performance evaluation of a fuzzy logic based temperature control strategy in a Guarded Hot Box Test Facility using three types of building materials-a single glazing, a double glazing and a plank of Extruded Polystyrene (XPS) as test specimens has been done and compared.

ABSTRACT. Polymer solar cells (PSCs) have attracted great interest in photovoltaic technologies due to their unique advantages including low cost, flexibility, large area coating, roll to roll fabrication, solution processible approach, etc. Recently, polymer functionalized reduced graphene oxide (rGO) nanocomposites has opened a new strategy to develop high efficient hybrid photoactive materials for PSCs. In the present work, benzimidazole based ruthenium (Ru) complex functionalized polymer grafted rGO sheets are synthesized by using simple chemical approach. The charge transfer occurs between Ru functionalized polymer and rGO sheet that extends its absorption in the entire solar spectrum (UV-vis-NIR region). A significant decrease in the photoluminescence (PL) intensity of composite with rGO confirms that the enhanced separation of photogenerated electron-hole pairs than that of polymer-Ru without rGO. The position of G-band in Raman spectra is shifted from 1591 cm-1 of rGO to 1577 cm-1 for rGO/polymer composite that clearly indicates that the polymers are grafted on rGO sheets. A possible charge transfer mechanism between Ru and rGO via polymer is also proposed. Moreover, the prepared rGO/polymer-Ru nanocomposite (p-type) blended with PCBM (n-type) is used as a photoactive layer in bulk heterojunction PSCs device with normal device configuration (ITO/PEDOT:PSS/rGO:Polymer-Ru:PCBM/Al). The rGO/polymer-Ru in PSC exhibits few folds enhancement in open circuit potential (Voc) than that of polymer-Ru without rGO. Therefore, rGO supported nanocomposites can be used as an efficient photoactive material in hybrid PSCs.

ABSTRACT. Most of the isolated hybrid power systems (IHPSs) are in function directly by public private participation schemes. Steady state and dynamic conditions both require reactive power for the operation of IHPS but role of compensating devices become more important especially in presence of system dynamics due to load and input disturbances. Load demand and characteristics also plays an important role in deciding the requirement of reactive power compensation. In such systems, choice of compensating techniques for controlling system voltage directly depend upon the cost and quality of electricity required by the customers. This paper describes the scope of optimizing compensation cost using dynamic and static compensators together with composite load patterns. These composite load models are developed by changing the compositions of dynamic and static load pattern.

ABSTRACT. Biodiesel is a low-emission, diesel substitute fuel made from renewable resources. The most common way to produce biodiesel is through transesterification. Conventional method of transesterification has several drawbacks such as: requires high alcohol/oil molar ratio, requiring more expensive separation of unreacted raw materials and low reaction rates. In this paper as process intensification, reactive distillation has been proposed for transesterification of triglyceride and methanol for biodiesel production. Aspen simulations were performed to test for the feasibility and process design of lab scale reactive distillation column. Effect of different process parameter viz. molar ration of alcohol to oil, flow rate of feed, reflux ratio and reboiler duty on yield of biodiesel production were studied. The effect of different alcohol viz. ethanol, propanol and butanol were also studied on the performance of reactive distillation column.

ABSTRACT. In the last decade there is a steady increase in electric power consumption, the available transmission lines are reaching critical limits of ampacity and sag, there exists an intricacy in finding corridors to construct new overhead lines in many industrialized countries including India. It becomes impossible to obtain the rights of way for new transmission lines. Hence, present situation demands the use of available transmission/distribution lines representing a low cost solution than going in for expensive underground transmission. Increasing the transmission capacity of overhead lines using high temperature high current low sag (HTLS) conductors, replacing original ACSR conductors with approximately the same diameter is one of the techniques. HTLS conductors are capable of withstanding high-temperature, continuous operation above 200°C without loss of tensile strength or increase in sag. As the HTLS conductors are of new origin, the literature available on the performance of these conductors is scarce and also several of the projects using HTLS are being executed in the country. It was felt necessary to conduct some simulation and experimental study on the performance of HTLS conductors. In the present work, a computer program is developed in accordance with IEEE Std.738 to estimate the current and temperature distribution for various HTLS conductors. Parametric study is conducted for steady state surface temperature, thermal time constant, change of emissivity, absorptivity etc for various ACSR and HTLS conductors. Experimental verification has been carried out on different types of ACSR and HTLS conductors/accessories in the laboratory. A Comparison of the simulation and experimental results will be presented. A Graphical User Interface (GUI) has been designed to get the optimal accessories dimensions suitable to be used for the newer HTLS conductors. Also the magnetic field near the vicinity of the HTLS conductors is estimated.

ABSTRACT. This work focuses on the study of aqueous Monoethanolamine (MEA) as a solvent for post combustion capture by evaluating the MEA - CO2 capture process both theoretically and experimentally. An experimental study has been conducted to understand the absorption of CO2 in aqueous MEA solution at 303 K in a packed column with a diameter of 0.048 m and randomly packed with 10 mm glass rachig rings. Experiment was conducted by varying the solvent flow rate from 7.5 to 20 LPH, and at a gas flow rate of 23.25 LPM. The results show that the KGaV value increases significantly when the L/G ratio increases. A CO2 removal process simulation of absorber has also been performed with ASPEN Plus using rate based simulation in RADFRAC model based on electrolyte-NRTL property method assuming the zwitterion mechanism.

ABSTRACT. A facile soft-template self-assembly strategy is reported to synthesize monodispersed ZrO2 hollow nanospheres of size 28 ± 2 nm as a candidate for anode material in lithium ion batteries. ABC triblock copolymeric micelles of poly(styrene-b-2-vinylmethyl pyridiium iodide-b-ethylene oxide) (PS-PVMP-PEO) with Core-Shell-Corona architecture serve as an efficient micelles for synthesis of ZrO2 hollow nanospheres using Zr(IV)butoxide as metal source. On dissolution of the above polymer in appropriate solvents, PS blocks become hydrophobic whereas the PVMP and PEO blocks attain hydrophilic character. Thus in the present approach, the PS-block (core) acts template for formation of hollow void space, the PVMP block with positive charges serves as reaction site for sol-gel reaction of Zr(IV)butoxide, and the PEO corona domain stabilizes organic/inorganic composite particles. The micelles as well as the ZrO2 hollow nanospheres were well characterized by dynamic light scattering (DLS), transmission electron microscope (TEM), X-ray diffraction (XRD), thermal analyses (TG/DTA), FTIR and nitrogen sorption analyses. The ZrO2 hollow nanospheres were further explored as anode materials for lithium ion batteries. The nanostructured electrode delivers a stable capacity of 87 mAh/g after 50 repeated charge/discharge cycles at reasonably high current density of 1C rate.

ABSTRACT. An experimental study was carried out to produce biodiesel from different kinds of non-edible feedstock. Operating parameters for different feedstock have been optimized with respect to percentage yield of production and viscosity. The most common method of biodiesel production is transesterification. Palm, karanja, mahua, linseed and castor oil are among the few of the non-edible oils. Along with this waste cooking oil can also be considered as non-edible oil as it is mostly thrown away. The process of transesterification depends on various factors like reaction temperature, stirring rate, molar ratio of alcohol to oil, amount of catalyst and reaction time. Depending upon the acid value, the number of steps of transesterification is determined. If free fatty acid is greater than 2.5% then two step transesterification is carried out. Karanja and mahua oil undergo two step process because of high free fatty acid content. The main objective of the study is to optimize the reaction parameters of different kinds of oil based on kinematic viscosity and percentage of yield obtained.

ABSTRACT. The installation of PV system at a place for optimum yield is influenced by various factors; geographic location, system design and various environmental factors of the location. This study presents the effect of shading and mismatch due to the module inter-connection configuration and mismatch in the characteristic of the individual cells of a module. Different percentage area of a single cell of a module is shaded and current and module power output at varying solar radiations is measured. Non-uniformity in the behavior of the cells is observed when a single cell of a 100Wp module is shaded individually at a time at constant radiation. This behavior due to partial shading of a cell or module leads to mismatch effect on the module performance which affects the overall system output. Mismatch effect is also observed by connecting a number of different capacity modules together in different connection configurations. The array consisting of different module configuration showed different behavior when exposed to constant radiation thus leads to decrease in the current generation of the system by 80%; thereby decreases the power output of the system.

ABSTRACT. A transient global numerical model has been carried out to simulate the multi-crystalline silicon growth process by the directional solidification method. A two dimensional axisymmetric model was used. The heat transfer problems such as conductive, convective and radiative heat transfer were coupled with our model and these problems were solved iteratively using the finite volume method. The heater element has been modified in the present work to produce a high quality multi-crystalline silicon ingot. The change has been made to control the temperature distribution. By controlling the temperature distribution, we can also control the melt crystal interface of the ingot. The shape of the melt-crystal interface of the ingot, the temperature distribution in the crucible and the heat flux from the melt as well as from the crystal have been studied. Finally, the simulation results show that the modification in the heater element keeps the melt-crystal interface as planar in the DS system, also it gives better results than conventional system.

ABSTRACT. High R/X ratio and significant voltage drop causes substantial power losses along the distribution network. In this paper optimal location and size for D-STATCOM is determined for radial distribution networks under reconfigured network to reduce the power loss which in turns save the energy and environment. The main contribution of the paper is: • D-STATCOM allocation using index vector method for radial distribution network with and without reconfiguration, • D-STATCOM size calculation using variational techniques for RDS with and without reconfiguration, • Impact of CP,CI,CZ, and realistic ZIP load model including load growth on D-STATCOM placement, • Energy Saving with improvement in voltage profile, reduction in power losses with D-STATCOM placement under reconfigured network, • Cost analysis with and without D-STATCOM Placement under reconfigured network, • Results are compared with existing technique proposed in literature. The proposed method is tested for D-STATCOM allocation in IEEE 69-bus radial distribution systems. Results show the considerable improvement in voltage profile, reduction in losses and, energy saving under reconfigured network.

ABSTRACT. Wood based down draft gasifier is capable to produce tar free and quite clean gas. The operation of down draft gasifier is trouble free compare to the other types of gasifier. Based on these facts, a down draft gasifier of 15 kW thermal power is designed to evaluate its performance using neem, babul and mixed wood as feed stocks. The size of babul and neem wood are 30 mm*20 mm* 20 mm and mixed wood are of 20-25 mm diameter and 30-35 mm length. The performance of gasifier is evaluated by comparing the thermal efficiency, temperature analysis and gas chromatography using three woods in the experimentation of gasifier.

ABSTRACT. Application of solar photovoltaic systems at a large scale is becoming increasingly interesting for researchers, policymakers and investors. Singh and Banerjee (2015) [1] have presented a methodology for estimation of the rooftop solar photovoltaic potential of a city. The methodology has been applied and illustrated for the Indian city of Mumbai (18.98 N, 72.83 E). In this paper, different configurations of the solar panels to be used for the Mumbai rooftop solar photovoltaic scenario have been analyzed and compared in terms of their impact on the generation from the scenario. The three possible configurations studied and compared in this study are – fixed tilt configuration, two-point system configuration, and horizontal N-S axis E-W tracking. The results show that for the fixed tilt configuration, the best tilt angle for year-round optimal performance is same as the latitude of the place, i.e. 19deg. However, optimization of seasonal output would warrant another tilt angle. Further, it has been found that, as compared to the fixed tilt at 19deg., the two-point system gives 2.21% higher annual plane-of-array insolation; and horizontal N-S axis E-W tracking gives 10.18% higher annual plane-of-array insolation. However, in terms of the annual generation from the large scale Mumbai rooftop scenario, the gain is only 1.97% with the two-point system, and 9.62% with the horizontal N-S axis E-W tracking configuration, as compared to the fixed tilt at 19deg. Incremental cost-benefit analysis for the excess capital expenditure on the tracking equipment has also been done. For this analysis, the Average Unit Cost of Power Supply for India has been taken into account, which is found to have a CAGR of 8.57% over the last decade; discount rate has been estimated as per the Renewable Energy Tariff Regulations passed by the Central Electricity Regulatory Commission (CERC), and has been found to be 10.76%. The ensuing analysis gives a discounted payback period of around 13 years for the excess capital expenditure due to the tracking equipment costs.

ABSTRACT. Carbon Capturing and Sequestration (CCS) is dawning to mitigate the environmental anthropology. Unfortunately, applying CCS decreases the overall efficiency of power plant by almost 10%. More development of CFB oxy-combustion –which services CCS– is needed to compensate the decreased in efficiency. Main barrier of high oxygen concentration combustion is limitation allowed temperature. This study suggests new arrangement toward using pure oxygen and zero or near zero exhaust gas recirculation (EGR). A zero-dimensional model for rate of heat release was developed based on the oxygen concentration. The novel feeding arrangement commences the third generation of CFB oxy-fuel combustion with zero EGR.

ABSTRACT. This paper reports the elimination of Lower order Harmonics (LOH) in 11-Level Cascaded Multilevel Inverter (CMLI) feeding a 3-Phase Induction Motor Drive using Modified Cat – Particle Swarm Optimization Technique. 11-Level CMLI has been simulated in Matlab 7.12.0 feeding a 3-Phase IM Drive. The switching pattern has been formulated and coded using SHE Technique. For the minimization of Lower order harmonics (LOH) , Modified Cat PSO algorithm has been coded in Matlab to solve a system of nonlinear transcendental equations. In this proposed method, Cat-PSO algorithm has been modified to increase the search space and obtain global minima. The results show elimination of harmonics up to 19th order for the modulation Index (MI) between 0.6 and 1.08.

ABSTRACT. Daylighting is an important element of energy efficient building. It not only adds to energy sustainability, but also has profound impact on the behavior and performance of occupants residing in the building. This paper is an investigation of daylight usability of a naturally ventilated residential building in an urban built environment through computer simulations. Annual light exposure and useful daylight illuminations (UDI) are analyzed by varying orientation and window to wall ratio (WWR) of the building. This aim of this study is to provide information on the impact of building orientation and WWR on the overall daylight performance, so that better daylight designs can be promoted and evaluated. Daylight performance analysis have shown maximum illuminance usability in the southwest direction, and its optimization with 50% WWR, increased the overall ambient illuminance in the room by 67%.

ABSTRACT. Conventional jaggery making with a pan furnace consumes entire bagasse for evaporation of water. Hot spots during boiling of juice causes caremilization of sugar. It gives dark brown colour to jaggery, which has low market value. Chemicals like lime, phosphoric acid and citric acid are used as clarificant to enhance colour of jaggery. Traces of these chemicals in jaggery are harmful to human health. In this paper, theoretical investigations on Freeze Pre-concentration of sugarcane juice using reversible heat pump are discussed. Freeze Pre-concentration of juice from 20°Brix to 40°Brix using reversible heat pump saves bagasse during initial 66% water removal. Water is removed in the form of ice. It requires 335 kJ/kg heat removal, which is 15% of heat addition during evaporation. Recycling of saved bagasse to field improves the yield of sugarcane crop. Juice is exposed to low temperature during pre-concentration. It reduces inversion of sucrose by reducing high temperature exposure time and it can be expected to improve the quality of jaggery by reduced exposure time to high temperature. Simple cycle analysis for FPCS of juice shows that COPc is 18 with R22 as refrigerant at -8°C evaporator and 3°C condenser temperature. Overall system COPc is expected, to be in the range of 9 to 12 after accounting for losses like cycling of thermal mass and heat gain from ambient. Power required for 1.5 TR FPCS is 0.6 kWe. Hence, electricity cost is about 0.1 INR/kg of jaggery produced (assuming INR 4/kWhe).

Payback period for FPCS is one year. Sugar inclusion in ice is estimated using empirical correlations for flow of solution over flat surface and it is 9.2°Brix. Further experimental investigations on sugar inclusion in ice, which forms inside the tube needs to be experimentally tested.

ABSTRACT. Microalgae are unicellular autotrophic/heterotrophic photosynthetically efficient organisms that use light energy and carbon dioxide (CO2). Biofuel production from Microalgae Chlorella species have long been identified as potentially good source because of their high oil content, fast growth and easy cultivation. Traditional terrestrial crops are currently being utilized as a feedstock for biofuels but resource requirements and low yields limit the sustainability and scalability. Comparatively, next generation feedstocks, such as microalgae, have inherent advantages such as higher solar energy efficiencies, larger lipid fractions, utilization of waste carbon dioxide, and cultivation on poor quality land. Chlorella vulgaris, Chlorella conductrix, Chlorella gonglomerata and C. parasitca are the common Indian species. In this paper we have highlighted the aspects of biodiesel production from the above cited strains of microalgae chlorella species to monitor the growth curve, biomass productivity, lipid content, fatty acid methyl ester (FAME) components and to evaluate the physical properties of the resulting microalgae biodiesel fuel.

ABSTRACT. Energy storage is the major issue in today’s era. Energy storage can supply more flexibility providing a back-up to intermittent renewable energy sources. Recent development has shown that super capacitors has high power density and energy as compared to conventional capacitors. It has unlimited cycle life , on hand charging methods, quick charging times etc. Super capacitors has many applications including power for hybrid electric vehicles cars, buses, trains, cranes , elevators and also short term energy storage. Two major outcomes of fabrication should be cost and size of super capacitor. Decreasing the particle size of activated carbon and manganese dioxide with the help of ball mill to make electrode can be one of the method to increase the flexibility of super capacitors. This paper deals with varying the particle size of powder in the making of electrode and it also gives the detailed analysis of various parameters related to super capacitor. Thus development of a low cost super capacitor can be a step forward in electrically operated devices. This paper presents the effect of particle size of activated carbon and manganese dioxide on the capacitance and energy density of super capacitor.

ABSTRACT. Metal-nitrogen-carbon (M-N-C) non-precious metal catalysts for oxygen reduction reaction (ORR) at the cathode of polymer electrolyte fuel cells (PEFCs) are necessary in need of further improvement to oxygen reduction. A new carbon supported composite catalyst comprising Sn and Co in varying weight ratio, namely 60:16, 50:20 and 40:24 electrocatalysts were prepared by a microwave-assisted ethanol reduction method followed by heat treatment at 750 oC. X-ray diffraction (XRD) and High-resolution transmission electron microscopy (HR-TEM) characterizations were carried out to determine the particle size distribution of the catalysts. The elemental mapping and the morphology of electro-catalysts were examined by Scanning transmission electron microscopy (STEM), Field Emission Scanning Electron Microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS) techniques. Cyclic voltammetry (CV) and Linear sweep voltammetry (LSV) techniques were carried out to study the effect of the catalytic activity of Sn and Co presents in the catalyst. Sn-Co/C catalysts exhibit significant improvement in ORR. The polymer electrolyte fuel cell with Sn-Co/C cathode catalyst exhibits a peak power density of 210 mW cm−2 operating under PEFC conditions.

ABSTRACT. A non isolated SIMO (single input multiple output converter) which produces boost, buck and inverted outputs simultaneously are presented in this paper. This converter has its application in electric vehicles in hybridizing alternative energy sources. The converter charges the battery source and at the same time it produces three different levels of voltages simultaneously without adding additional switches to the conventional converter. The proposed converter has two modes of operations depending on the charging and discharging states of the energy storage system (ESS).The operation of various modes of operation and its simulated results are discussed using MATLAB.

ABSTRACT. Fugitive methane emissions from fossil fuel extraction accounts for significant contribution towards greenhouse gas (GHG) emissions in India. Out of total GHG emissions of 1.4 million Gg-CO2 equivalent in 2007 from India’s energy sector, approximately 34,000 Gg-CO2 equivalent belonged to fugitive emissions from fossil fuel extraction [1]. Methane emission from coal mining and handling activities has increased from 0.555 Tg in 1991 to 0.772 Tg in 2010, as per national emission factors developed by CIMFR. These estimates have been prepared as a part of India’s Second National Communication to the United Nations Framework Convention of Climate Change (UNFCCC) and the Biennial Update Report (BUR).

With increasing demand of coal, current production is likely to touch around a billion tons by 2020. In this paper, projections have been made about the future coal production and also the future trend of methane emissions from coal mining and handling activities. The methane released from coal mining and also coalbed methane can supplement India’s scarce natural gas reserves and also act as a GHG mitigation opportunity. There are several technologies to achieve this in India, which include:

1. Coalbed methane (CBM): There exists an estimated potential of 400 BCM of coalbed methane of CBM in three provinces viz. Jharkhand, West Bengal and Chhatisgarh [2]. Commercial scale exploitation of CBM has already begun in India. 2. Coal Mine Methane (CMM): Three coalfields in the Damodar River Basin (Raniganj, Jharia and Bokaro) were studied as part of a project funded by the US EPA for feasibility of CMM. Kalidaspur and Ghusick collieries in the Raniganj Coalfield, Murulidih, Amlabad, Sudamdih and Parbatpur mines in the Jharia Coalfield and Jarangdih and Sawang collieries in the East Bokaro Coalfield appear to be favourable sites for CMM recovery. Opportunities for CMM recovery in these collieries shall be covered in details in this paper. 3. Ventilation Air Methane (VAM): Methane diluted by ventilating air in underground coal mines is vented to the atmosphere and may be captured for its gainful utilization. CIMFR, in association with Southern Illinois University at Carbondale, USA, completed a collaborative project on VAM utilization in India. The study revealed that that installation of just two rotary kilns can lead to revenue generation of US$ 2.8 million in two years. 4. Abandoned Mine Methane (AMM): There has been no effort to quantify the potential of AMM resource in India so far. It is imperative; therefore to initiate a study for evaluation of AMM resource potential in India.

Such mechanisms may serve as a valuable instrument to mitigate atmospheric methane emissions to the atmosphere and to find new pathways of clean energy deployment in India. This paper shall present an analysis for policy-makers and the stakeholders by providing a technological overview for augmenting clean energy resources in India.

ACKNOWLEDGMENTS The author thanks US EPA, USA and InsPIRE Network for Environment, New Delhi, for financial support.

REFERENCES

[1] Sharma SK et al (2011), Greenhouse gas inventory estimates for India, Curr Sci, 101, 405-415. [2] Garg A et al (2004), Indian methane and nitrous oxide emissions and mitigation flexibility, Atmos Environ, 38, 1965-1977

ABSTRACT. There are many non-edible oil seed bearing trees like Ratanjyot (jatropha curcas), mahua (madhuca indica), rubber seed (hevea brasilensis), nahor (mesua ferrea), karabi (thietiva peruviana) and karanja(pongamia glabra) etc have been found to be a prominent source of oil for biodiesel production. Among these species Pongamia glabra and Mesua ferrea satisfy the most convincing species due to their various attributes like annual seed yield, life span of the seed bearing tree, and most importantly the oil content of the seeds. The oil contents of Mesua ferrea and Pongamia glabra are 72% and 37% respectively. As the acid value of both the oils are high, hence, it has been reduced via esterification before going to alcoholysis. Here biodiesel was produced individually from both the seeds and blending both the oils in 1:1 ratio. We have compared the results of blended [(1:1) oil] biodiesel with the individual biodiesel prepared from Mesua ferrea, Pongamia glabra and also with the standards. The FAME (Fatty Acid Monoalkyl Ester) produced by this method gives data in accordance with the results determined as per the ASTM and EN 14214 standards for evaluating the biodiesel fuel qualities like density at 15°C (gm/cc), cloud point (°C), pour point (°C), acid value (mg/KOH/g), kinematic (cst), viscosity at 40 °C, flash point (°C), oxidation stability (hours), calorific value (MJ/kg) and carbon residue(%wt). We recorded remarkable fuel quality enhancement in the blended biodiesel which can used as a better fuel than the individual biodiesel prepared from both the oils.

ABSTRACT. India’s developmental needs in the near and long-term future will be strongly interlinked with the need to provide steady electricity to its cities and villages. The current fleet of Electricity Generating Units (EGUs) in India is mostly coal-based. These coal-fired power plants lead to a substantial amount of CO2 emissions. Due to international climate obligations, there might be a need to limit the amount of unmitigated CO2 emissions being emitted into the atmosphere. Mitigation of such emissions at coal-fired power plants offers an easily controllable way of reducing such emissions. The mechanisms to reduce emissions in coal-fired power plants may be through installation of super-critical units, repowering the plant with Integrated Gasification Combined Cycle (IGCC), use of coal blended with biomass. More radical emission cuts may be obtained by retrofitting the existing plants with CO2 Capture and Storage (CCS), a technology with the ability to reduce the emissions by 80-85% of the current emissions levels. This paper begins with a brief insight into some of the mechanisms to cause emission reductions in coal-fired power plants. It focuses mainly of how retrofitting the power plants with CCS technology will affect the techno-economic of the plant. Three types of plants will be analyzed, viz, Low performance, medium performance and high performance; the categorization being based on the current Indian fleet of EGUs. We analyze five pathways for mitigation, with two focusing on efficiency improvements and three on CCS technology. The results show that overall cost of avoidance for CCS ranges from US$ 59.54 to US$ 85.41 per tonne of CO2. There is a strong incentive for repowering of old plants to supercritical units and their subsequent retrofitting with CO2 capture systems than direct retrofitting of low performance plants.

ABSTRACT. To achieve sustainability goals, various strategies have been used which include symbiotic strategies with other companies. Such symbiotic strategies are based on the concept of industrial ecology (IE). IE emphasises on the importance of symbiotic interactions among various companies as it would reduce overall waste emission, raw material and energy consumption. Since symbiotic relationships normally occur among processes co-located within the same vicinity, the concept of eco-industrial parks (EIPs) emerged. Companies in an EIP engage in material and energy exchange programmes in a mutually beneficial manner. In this sense, a biomass-based tri-generation system (BTS) could serve as a facilitator for an EIP as it produces heat, power and cooling energy simultaneously on-site. However, it is arguable whether a BTS-driven EIP would be economically viable since each company would have its own profit-oriented goals. To address such issue, this work presents an optimisation-based negotiation framework for plants in an EIP. Such framework combines both cooperative game model and stability analysis developed by Maali and Wang et al. respectively.

ABSTRACT. The rapid rise in energy consumption in the country results in shortage of fossil fuels such as oil, coal and petroleum products. The fall of rupee against dollar in world market lead to concern about the availability of energy requirement for sustaining our economic growth in India. Increased use of fossil fuels and petroleum product in recent years leads to environmental problems both locally and globally. So looking at huge demand of diesel for all sectors of economy, the biodiesel is being viewed a substitute of diesel. The vegetable oils, animal fats and grease are the main feed stocks for the biodiesel production. Biodiesel fuel properties are quite comparable to diesel. From the various research analysis it has been identified that biodiesel have two major problems: fuel stability and its performance under cold conditions. Various researchers have worked extensively on improving the biodiesel stability but very less work has been reported on cold flow properties of biodiesel. The poor cold flow properties create problem in engine operation by choking the fuel lines and filters. The present paper provides the impact of microalgal oil on the cold flow properties of edible and non-edible

ABSTRACT. One of the bottlenecks to efficient performance of microbial fuel cell (MFC) systems has been the low electron transfer from the bacterial cell membrane or membrane organelle to anode. In this study, an attempt was made to develop polyester graphite electrodes by deliberate modification of the bulk matrix material with selected redox species (metal salts) that could alter the electrochemical behaviour suitable for microbial metabolism and promote biofilm formation. Different metal salts used in this study were CuSO4.5H2O, FeSO4.7H2O, MgSO4.7H2O, MnSO4.H2O, CoSO4.7H2O, ZnSO4.7H2O and NiSO4.6H2O. The morphology and surface chemistry of modified electrodes was investigated. A laboratory-scale H–Shaped Pseudomonas catalyzed microbial fuel cell (MFC) was investigated, for its performance in decolourizing synthetic wastewater, containing azo dyes. The azo-dye investigated in this study was methyl orange. The effects of different polyester graphite composites were tested to reduce the internal resistance of MFC in order to maximize the power density.

Among the different electrodes tested as an anode in the MFC, the electrode developed with MnSO4.H2O produced the highest power density (270 mW/m2) with a decolourization efficiency of 94 ± 4.2 %. It was observed that the power output increased substantially (almost 3 fold), using MnSO4.H2O modified electrode when compared with the graphite block (99 mW/m2). This study confirmed that the redox active sites on the fabricated electrodes were effective in improving the cell-electrode interactions compared to the bare graphite electrode, which could significantly boost the power density in MFCs.

ABSTRACT. In spite of the unprecedented laws in India, there has been a steady deterioration of all the environmental sub-systems during the past five decades. This happened due to lack of adequate capacities of the sewage treatment facilities across the nation which leads to a large volume of wastewater discharge into natural watercourses. In this study, an assessment in terms of energy consumption has been carried out for the engineered natural treatment systems based facilities for wastewater treatment and the most commonly practiced wastewater treatment technology (Activated Sludge Process), worldwide. The assessment of energy consumption for wastewater treatment systems has been performed for the global context in general and Indian circumstance in particular. The parameters selected during assessment of the above mentioned technologies include: electrical energy consumed during operation of treatment facility, corresponding coal required for generation of electricity as well as assessment of the long-term impacts on environment in terms of global warming potential, acidification potential and abiotic resources depletion potential. Study reveals that the use natural treatment systems for management of wastewater is an appropriate technological solution to enhance the efficiency of treatment at lower costs, which also attributes to be favored by climatic condition in Indian sub-continent.

ABSTRACT. In the present paper thermohydraulic performance of plane as well as wavy fin absorber solar air heater has been investigated. A mathematical model is presented and compared with the plane solar air heater. Wavy fin has been used as an extended surface which increases the heat transfer area simultaneously increasing heat transfer coefficient due to its wavy shape. The effect of mass flow rate and the fin pitch were investigated on the thermohydraulic performance. The thermal and effective efficiencies increased with the increase in mass flow rate and decrease in fin spacing. The mathematical model provides reasonable predictions of the performance of wavy fin solar air heater and can be a useful in designing such type of solar air heater with wavy fins within the investigation range.

ABSTRACT. In this paper an attempt has been made to analyze the thermal efficiency, outlet air temperature and exergy efficiency on a comparative basis. Thermodynamic assessment of the proposed solar air heater, shows that thermal efficiency of the wavy finned solar air heater to be 1.34 times higher than offset rectangular finned solar air heater and 2.66 times higher than plane solar air heater. The maximum exergy efficiency has been found to be 5.99% for the wavy finned solar air heater. It has also been observed that the wavy finned solar air heater delivers higher outlet temperature and thermal efficiency in comparison to offset rectangular finned solar air heater for the same fin spacing. Design plot shows that at fixed value of temperature rise parameter, wavy finned solar air heater shows higher thermal efficiency followed by offset finned solar air heater and then plane solar air heater. Overall, both thermal efficiency and exergy efficiency of wavy finned solar air heater is superior.

ABSTRACT. This paper presents an electro-thermal model of Vanadium Redox Flow Battery (VRFB) showing a prediction of significant changes in its thermal behavior with changes in control parameters such as State of Charge (SOC), Charging Current, Flow Rate of electrolytes and ambient temperature. A generic model of VRFB SOC estimation based on Nernst equation is developed and the result is taken as input variable to study the variation of VRFB stack temperature. The thermal modeling of VRFB is designed based on energy balance equations of battery stack and two electrolytic tanks. This model has been found to be very useful in forecasting different stages of battery stack electrolyte temperature development for different levels of charging current. The battery SOC estimation and thermal characteristic model are developed in MATLAB/SIMULINK environment. The overall model has been verified satisfactorily with a 6kWh VRFB system and it can be further employed in control and optimization of battery temperature within desired limit and to design dedicated charge controllers to increase its performance and to ensure longer life cycle.

ABSTRACT. Boric acid (BA) is one of the boron dopant sources used in recent years to fabricate emitters for n-type c- Si solar cells. Boric acid solution with concentrations less than 4% is sufficient enough to get doping concentrations with sheet resistance values 10 Ω/sq to 90 Ω/sq under different diffusion conditions. Isotopic analysis of BA diffused emitter, optimized for different sheet resistances have been studied in this work. Cs ions of 1KV 300x300 raster ions have been used for the emitters and it has resulted detection of 11B and 28Si isotopes in all the boron diffused samples. Isotopic analysis of borosilicate glass (BSG) and boron rich layer (BRL), corresponding to different dopant concentrations, also shows isotope detections and they vary according to natural abundance.

ABSTRACT. Boron diffusion introduces crystal defects during its diffusion and is an unavoidable phenomenon in emitter formation in n- type solar cells. Also, boron precipitates formed during boron source diffusion degrades the device performance. In this work, the degradation of the bulk properties due to B diffusion in front side emitter formation is studied with chemical passivation. The diffusion is done with boron spin on dopant (BSOD) and the boron precipitates formed during the diffusion process is minimized by process controlled steps and chemical treatments. For sheet resistance values less than 70Ω/□, it is seen that the bulk minority carrier lifetime of the device decreases to less than 50% of values after the process of diffusion. Presence of boron precipitates lower the carrier lifetimes and there is an increase in the bulk properties after its removal. The values are comparable to the mostly used BBr3 liquid dopant source and is seen that for the same diffusion conditions of BSOD and BBr3, the values are lowered by nearly 30µs for the BSoD source.

ABSTRACT. Laser processing is increasing its footprint in silicon solar cell fabrication because of availability of different laser systems, better control over their processing parameters and their potential for adaption in industrial manufacturing. Laser processing introduces defects in silicon due to local heating and hence demands for fine tuning of the parameters to minimize the damage. In this work, a microsecond pulse length 1070nm fibre laser is being used for deep junction formation and for laser fired contacts in silicon solar cells. Variation in processing conditions is achieved by changing the pulse length, the power density and the scanning speed of the laser. Raman spectroscopy has been used to assess the impact of these conditions on defects introduced by them in silicon. Variation in full width half maximum (FWHM) of Si Raman peak is established as an indicator of damage created in silicon and thus utilized for optimum laser parameter tuning.

ABSTRACT. This work investigates the status of energy losses due to power factor of agricultural loads on one distribution transformer of a village in Sangli, an agriculturally intensive district of Maharashtra. Data, simulations, and an intervention involving capacitor installations, are used to estimate loss reduction possible through the use of capacitors. If taken as representative of the situation in the state, the proper use of capacitors can lead to saving of ~Rs.150 crores per year to the utility. The paper examines the reasons for failure of the current process instituted by the distribution utility, and proposes solutions. Implementation of capacitors for all loads was undertaken as part of the work to get a clear understanding of the contributing factors.

ABSTRACT. India is heavily dependent on coal for electricity generation. About 60% of the power generated in 2014 was from coal fired plants [1]. Also, coal will continue to make a significant contribution to the power generation mix in the country over the next couple of decades [2]. Many more coal power plants are expected to be built in the next few years and most of them would be super-critical or ultra-super-critical plants [3]. The coal plants are responsible for large emissions of CO2 – a major greenhouse gas (GHG) considered to be responsible for climate change. India being the 3rd largest CO2 emitter in the world, there is a need for exploring various carbon mitigation techniques with ever increasing concerns about climate change [4]. Carbon Capture and Sequestration (CCS) is one such mitigation option wherein CO2 emitted by the power plants and other industries is captured and transported to a storage site where it is isolated from the atmosphere permanently [5]. This study helps in understanding the economic & environmental impacts of implementing CCS in the proposed Supercritical Coal power plants with the help of Integrated Environment Control Model (IECM-cs) [6]. Two technology options, viz. post-combustion CO2 absorption from flue gas and oxyfuel combustion with CO2 capture, have been analyzed. The proposed super-critical coal plant is simulated with and without the CCS options, and the impact on performance, costs and environmental emissions has been estimated in each case. This comparative assessment of these CCS technology options will help the policy makers in understanding the relevance and potential of CCS in India.

References [1] Executive Summary: Power Sector, Government of India, Ministry of Power 2014. Details available on http://www.cea.nic.in/reports/monthly/executive_rep/dec14.pdf [2] International Energy Agency, World Energy Outlook, 2012. Details available at http://www.iea.org/publications/freepublications/publication/WEO2012_free.pdf [3] Ministry of Power, GoI, http://powermin.nic.in/indian_electricity_scenario/introduction.htm/. [4] Trends in Global CO2 Emissions: 2014 Report, PBL Netherlands Environmental Assessment Agency. Details available on http://edgar.jrc.ec.europa.eu/news_docs/jrc-2014-trends-in-global-co2-emissions-2014-report-93171.pdf [5] Climate Change 2014: Mitigation of Climate change, Working group III Contribution to the Fifth Assessment report of the IPCC, 2014. Details available on http://www.ipcc.ch/report/ar5/wg3/ [6] IECM, http://www.cmu.edu/epp/iecm/

ABSTRACT. Major portion of today’s energy demand in India is being met with fossil fuels. Hence, it is high time that alternate fuels for engines should be derived from indigenous sources. As India is an agricultural country, there is a wide scope for the production of vegetable oils (both edible and non-edible) from different oil seeds. The present work focused only on non-edible oils as fuel for engines, as the edible oils are in great demand and far expensive. Experimentations are carried out in a more popular Kirloskar single cylinder, water cooled CI engine. Major problems associated with vegetable oils are higher viscosities, lower heating values, rise in stoichiometric fuel air ratio and thermal cracking. The present study has focused on utilization of non-edible oil biodiesel and their blends with diesel. The characterizations of biodiesel blends are done in fuel and combustion laboratory. From the experimentation, it has been observed that 20 % blend of pongamia biodiesel with diesel is the best suited blend, without heating and any modification of the engine. Methyl ester of pongamia is the better performing fuel due to better combustion and lower emissions. An attempt has been made to study the combustion processes in a compression ignition engine and simulation was done using computational fluid dynamic (CFD) code FLUENT. Turbulent flow modelling and combustion modelling was analyzed in formulating and developing a model for combustion process. This describes the development and use of sub models for combustion analysis in direct injection (DI) diesel engine. The Computational Fluid dynamics (CFD) code FLUENT is used to model the complex combustion phenomenon in compression ignition (CI) engine in the present study. The results obtained from modelling were compared with experimental investigation. It has been observed that the experimental results are closer with the CFD modelling.

ABSTRACT. In recent years, the world is facing a problem of global warming and climate change due to increase in industrialization and motorization. Similarly developing country like India is facing imminent shortage of fossil fuel and its maximum revenue is spent for import of oil. Therefore there is need to take research work on discovery and exploration of ways to utilize alternative fuels to replace the conventional non-renewable fuels. Biodiesel is one such promising alternative fuel to use in automobile, gas turbine, boiler and other furnace application. In the present study an experimental investigation of combustion characteristic of Jatropha methyl ester (JME) and its blends with diesel on gas turbine combustor are carried out. During the experiment, fuel mass flow rate and air temperature are kept constant. For different equivalence ratio, flame temperature and emission parameter are measured with the help of K-type thermocouple and exhaust gas analyser. It is observed that the flame temperature increases with increase in JME percentage in diesel and major pollutant such as CO, CO2 and unburned hydrocarbon emission decrease while NOx emission would increase when compared with diesel fuel. The results indicate that there may be beneficial for country and environment using biodiesel in gas turbine combustor to produce power.

ABSTRACT. Brimmed diffuser shrouds for small wind turbines are being used to accelerate the wind velocity in smack wind regimes. Many experimental and numerical studies have been carried out on the shrouds to augment velocity/wind power. In this paper, a flow analysis and parametric study have been done using computational fluid dynamics on a brimmed diffuser shroud with the variations in geometric details of a diffuser 2-D axisymmetric model (without modeling the wind turbine). Variations in Brim width/thickness in both windward and leeward sides and variations in diffuser height at the exit are the parameters considered in this investigation. The study cases are a) Brim width as 0.025m, 0.075m, and 0.1000m which is initially fixed in Reference model as 0.050m for 1) Windward case (WC): By varying the thickness of the brim in the windward direction and maintaining all the other dimensions of the model constant. 2) Leeward case (LC): By varying the brim thickness leeward side and maintaining all the other dimensions of the model constant. b) Diffuser height as 0.350m, 0.400m, 0.450m where the initial height has been taken as 0.306m. Based on this flow analysis and parametric study the results corresponding to the augmented velocities are presented in this paper.

ABSTRACT. Graphene oxide filter paper (GOPER) is a powerful candidate as an adsorbent material for filtration applications. We develop surface tailored graphene oxide filter papers with controlled thickness and varying size which is used as a membrane for adsorption and filtration of various water pollutants mainly cationic and/or anionic dyes from industrial waste water. The removal efficiency is estimated to be more than 99 %. GOPERs are fabricated via vacuum filtration technique and possess very high flexibility and high mechanical strength. The diameter of the GP is 4-5 cm. The pore size of the GP is found to be around 7 nm by filtering out different sizes of Au nanoparticles and verifying the same using microscopic and spectroscopic studies. From the energy efficiency and environment point of view, GOPER has an advantage over other adsorbent alternatives as it is non-toxic, and fabrication and filtration are single step processes.

ABSTRACT. Air-conditioning represents the major component of energy consumption in commercial buildings in India. To reduce the space cooling load, a methodology is proposed to optimize the building design, using incremental integrated design approach and design of experiments methods. This methodology is applied over a three story building in New Delhi climate. For the building, using incremental integrated design, passive strategies are able to reduce the cooling load by 50% over the base case and low energy cooling techniques are able to reduce the cooling load by 50% over the passive case. Building is then optimized to use natural ventilation to the extent possible, while considering the uncertainty in input parameters, using design of experiments methods. It is found that during winter months, building can be operated just using natural ventilation during office hours, while maintaining thermal comfort. Natural ventilation is able to reduce the energy consumption by about 15% over the incremental design case. The final achieved mixed mode design consumes 55% less energy, has better views to the exterior, better daylighting and uses natural ventilation for 30% more hours as compared to the baseline case.

ABSTRACT. Cu2ZnSnS4 (CZTS), a quaternary p-type semiconductor, is a promising absorber material for solar cell due to its abundance and low toxicity. In this study, we report on the preparation of high quality Cu2ZnSnS4 thin films using single bath electrodeposition process via an optimized deposition potential and fabrication of CZTS thin film solar cell with graphene as a window layer. X-ray diffraction and Raman analysis validated the formation of kesterite phase of CZTS without any secondary phases at an optimized deposition potential of -1.4 V vs. Ag/AgCl. As a signature of highly pure crystalline films of CZTS kesterite phase, we observed a characteristic Raman peak at 338 cm-1 that corresponds to the vibration of sulfur atoms. Elemental analysis using energy dispersion analysis of X-rays (EDX) reveals a near ideal composition ratio of 2:1:1:4 for these films, and indicates the formation of the ideal stoichiometric compound. Furthermore, X-ray photoelectron spectroscopy analysis of the grown films illustrates an appropriate chemical composition and valence states of the constituent elements without a trace of free sulfur. Using the chrono- amperometry data and the Scharifker and Hill model we found that the nucleation mechanism for CZTS thin film is instantaneous. Optical properties demonstrated the optimum band gap of 1.5 eV for kesterite CZTS film prepared from a precursor electrodeposited at -1.4 V vs. Ag/AgCl. Mott-Schottky electrical measurements confirm the p-type nature of the film with a carrier concentration of 1017 cm-3, a flat band potential of VFB = 0.7 V and space charge region width of 0.2 μm. Further, CZTS thin film solar cells are fabricated with the device stack consisting of glass/ Mo (back contact)/ CZTS (absorber)/ CdS (buffer layer)/ ZnO/ Graphene with conversion efficiency of 3.5%.

ABSTRACT. Growing consensus about anthropogenic climate change and depleting fossil resource base across globe is forcing communities to seek for alternatives for fossil fuels. Biodiesel, alternatively known as fatty acid alkyl esters, is considered to be promising alternative to diesel. Due to diversity in available feedstocks and conversion routes for biodiesel production, it is very important to choose best available feedstock and conversion route for biodiesel production. Present study aims to evaluate different feedstocks and conversion routes by using Aspen plus process modeling approach for their effectiveness. Process simulation models for different configurations of conversion routes will be presented using Aspen Plus version 7.3. Influence of various operating parameters such as temperature, pressure, oil: alcohol ratio, free fatty acid concentration on transesterification process. Selected process models will be evaluated on some environmental and techno-economic criteria, such as carbon mitigation potential, cost of biodiesel, energy footprint, and water footprint will also be studied.

ABSTRACT. The thermal conductivity of the heat transfer fluid is the key parameter for quantifying efficiency of the fluid for heat transfer. Traditionally used fluids in thermal management systems such as water, glycols, transformer oil, engine oil inherently have very poor thermal conductivity, at least two to three orders of magnitude lower than solids. Nanofluids are a new class of heat transfer fluids which exhibit enhanced thermo-physical properties. However, tuning the characteristics of the nanomaterial fillers in these nanofluids is important for achieving desired enhanced performance. Here, we investigate thermal conductivity enhancements in copper nanofluids with respect to the surface chemistry and surface charge of the copper nanoparticles. Surface chemistry and surface charge dictate the particle-fluid and particle-particle interactions. We describe the thermo-physical property enhancements by tuning the surface parameters (surface chemistry and surface charge) of the nanoparticles at different concentrations and temperatures. The experimentally measured properties are correlated with the Maxwell Garnett model and Hamilton Crosser model. The enhanced thermal conductivity of the fluids lies well within the bounds of the effective medium theory.

ABSTRACT. In the present experimental study Jatrophacurcas biodiesel blends produced through Trans-esterification process is used along with application of different cooled exhaust gas recirculation (EGR) rates in a twin cylinder four stroke CRDI engine. Performance, emissions and combustion properties of an engine at constant speed were measured and analysed. The improvement in brake thermal efficiency (BTE) and reduction in carbon monoxide (CO), unburned hydrocarbons (HC) and smoke opacity were observed for the B20 biodiesel blend with marginal increase of oxides of nitrogen (NOx). EGR application has reduced the NOx emissions and peak pressure inside the combustion chamber due to lower flame temperature. Combining B20 blend ratio with 15% EGR rate has the potential to achieve ultra-low NOx without affecting other type of diesel engine exhaust emissions by maintaining same efficiency level.

ABSTRACT. Abstract: Thermoelectric materials are paid much attention due to its direct energy conversion from thermal energy to electricity or conversely from electricity to solid state refrigeration by employing electrons and holes as energy carriers [1]. The performance of thermoelectric device is depends on the dimension less figure of merit zT=(S^2 T)/ρκ where S is Seebeck coefficient, ρ is electrical resistivity, T is absolute temperature and κ is thermal conductivity of material. Here we present our observations of S doping at Te site in In2(Te1-xSx)5, (with x = 0.05, 0.01, 0.15). In the results we observed for the S concentration up to x = 0.15 shows electrical resistivity reduced about three order of magnitude (0.0070 Ωm) as compare to parent compound (5 Ωm) at 390 K without much deteriorate thermopower and also decreasing the lattice thermal conductivity. In this report we construct successful pathways to achieve enhanced TE performance (zT ≈0.016 at 393 K) and power factor (PF ~19 µW/mK2 at 265 K) by employed S doping in the polycrystalline In2(Te1-xSx)5, (with x = 0.05, 0.01, 0.15) compounds about high temperature and also at room temperature.

References:

1.T.M. Tritt, ed., Recent Trends in Thermoelectric Materials Research, Semiconductors and Semimetals, Vol. 70, treatise editors, R.K. Willardson and E. Weber (Academic Press, New York, 2001).

ABSTRACT. A novel Solar Steam Generator with Absorber Integrated Storage will be presented. Evacuated Glass Tubes are used along with reflector offering low concentration ratio reflectors to increase the stagnation temperature beyond the usual 230 to 270oC. The inner glass tubes are filled with heat storage medium to store the collected heat. A copper tube coil with aluminium foil fin is deployed in the storage medium to enable extraction of heat as and when needed. Heat loss from the bottom side is reduced using a multilayer rigid foam insulation under the EGT and reflectors. Top loss from the EGT outer cover is reduced by deploying a multiwall polycarbonate cover over the reflector and EGT. Durability is enhanced and maintainability is improved due to the enclosed reflectors. Storage medium temperature of 200 to 300oC are achieved with this design. Preliminary experimental data reveals that such collectors can be used to generate steam at 1 to 10 bar using the low cost seasonally tracked low profile collectors.

ABSTRACT. The key objectives of a production firm are the productivity and the cost incurred analysis. In case of manufacturing sectors new materials are being introduced regularly in order to accommodate the growing expectations and the need for modernization. In view of this, there is a necessity to identify the most suitable joining process for a particular material which would yield the best efficacy. In this study Al 6061 alloy is chosen for understanding its behavior when subjected to cold metal transfer (CMT). Experimental trails have been carried out based on design of experiments, energy incurred in the various trails of the different parameters are recorded and the corresponding changes in the micro structural behaviours and the depth of penetration is being recorded and influences are discussed.This research study is expected to provide an insight into the energy and its associated concepts which alters the choice of the manufacturing process.

ABSTRACT. Abstract: In the presence the mostly we use the conventional system for generation of energy but its capacity is not more than 300 year. Now we can to divert towards the non-conventional energy sources like Solar, Wind, Waste Biomass and Tidal etc. In the India every year million tons of waste biomass produce because India is an agricultural country. Every day energy demand is increases so the biomass is the major source of power supply by converting in to the conventional form. In this research paper we designed the fluidized bed gasifier and develop the experimental set up of diameter 122mm and height 1100mm and done experiment at two Equivalence Ratio 0.3 and 0.35 with two different biomass Bagasse and Saw dust. The bed temperature maintained between the 600 - 800 °C. We show the carbon conversion efficiency increase 62.14% to 77.22% and cold gas efficiency (gasifier efficiency) reduce 43.25% to 41.85% when going toward 0.3 to 0.35. Also the heating value of the gas always decrease when going towards the 0.3 to 0.35 ER. And the composition percentage of producer gas change in the CH4, CO, H2 and CO2.

ABSTRACT. India`s substantial and sustainable growth is highly dependent on the technology advancement, methodology adopted and legislative framework which foster energy harvesting from country`s non-conventional energy resources as alternative to conventional energy resources. Conventional energy sources are facing increasing pressure due to its scarcity, emission of green house gases (CO2, SO2, NOx) enhancement in toxicity which are threat to ecological system, major impact on soil pollution, environmental pollution, human health as well as flora and fauna. Concern about environment, climate change and threat from greenhouse gas emission are the powerful drivers for solar energy harvesting. There is no national, unified legislative framework for renewable energy including solar energy except the Electricity Act of 2003. India has ratified UN Convention on Climate Change and Kyoto Protocol and supported renewable energy projects. In this paper we are reporting the solar energy harvesting methods, its impact on environment, various solar energy projects, law and regulation on renewable energy and role of implementing agencies.

ABSTRACT. Ethylene Vinyl Acetate (EVA) is most commonly used protective film for photovoltaic (PV) cells. This cross linked EVA film faces different environmental conditions during this total life time, this conditions mainly affected PV reliability. It is difficult to achieve all mechanical and thermal properties. So improve cross linked EVA reliability (VA 40%), corresponding changes of mechanical and thermal properties are analyzed. One important key component of PV modules improving lifetime with help of choosing proper encapsulated materials. Main scope of this paper is focused on thermal and mechanical analysis using DSC, DMA and water absorption of cross linked EVA.

ABSTRACT. Energy conservation using a Dedicated Outdoor Air System, DOAS, to Indirect Evaporatively Precool the supply air using will be presented. This is achieved using an Aluminium Air to Air Heat Recovery Unit (AtAHRU) cum Scrubber. An extrusion with novel Enhanced Flow Passages is used to achieve improved performance. Benefits of patented corrugated flow passages of the modular AtAHRU will be discussed. An Indirect Evaporative Cooler for fresh air using exhaust air is developed, installed and commissioned in Bio School BSL2+ facility in association with Klenzaid Contamination Control Pvt Ltd, Mumbai. The exhaust air of 3,025 m3/h is scrubbed with water which cools it close to its wet bulb temperature. This cooled exhaust air is then used to precool the fresh air of 3,240 m3/h before being supplied to Variable Refrigerant Flow Air Conditioning system in the Bio Clean Room. Two ~1,690 m3/h (1,000 cfm) unit are integrated with a 9 TR (2 TR + 3 TR + 4 TR) condensing unit in the Air Handling Units. Preliminary data reveals that about 4 TR cooling load is reduced out of a total of 9 TR deployed, a saving of over 40%.

ABSTRACT. In the present study, we have proposed a three parameter material model to describe the constitutive relationship of electro active polymer. The analysis of time dependent behavior is important for its wide industrial application such as actuators and sensors. These classes of materials are used for efficient and cost effective alternative energy appliances. To develop the material model uniaxial tensile recovery experiment was performed at different stretch rate from 0.02 s-1 to 0.5 s-1. The time dependent visco-hyperelastic material model is of Jeffrey type. In the Jeffrey model elastic component is considered as Gent type limited elastic part coupled with viscous component. The material parameters of the proposed model were obtained from the experimental hysteresis curve. It is observed that Strain stiffening effect at large stretch rate Gent type material model best characterizes the loading and unloading experimental data.

ABSTRACT. Solar potential assessment is very useful for various applications like solar heating, agriculture, solar lighting system and solar power plant erection etc. The objective of this study is to identify theoretical potential of solar radiation for solar energy applications in hilly state Himachal Pradesh. Artificial Neural Network (ANN) is used to predict solar radiation using site specific measured data of Hamirpur for training and testing. The input variables used are temperature, rainfall, sunshine hours, humidity & barometric pressure to predict solar radiations. To identify the effect of various input parameters on solar radiations three ANN based models have been developed represented by ANN-I5, ANN-I4 & ANN-I3.To obtain best prediction result, the number of input parameters of the input layer have been varied between 3 to 5 and hidden layer neuron have also been varied between 10 to 20. The best mean absolute percentage error (MAPE) calculated for these models (ANN-I5, ANN-I4 & ANN-I3) are 16.45%, 18.77% and 19.39% respectively. The ANN-I5 (temperature, humidity, barometric pressure, rainfall and sun shine hours), model showed good prediction accuracy as compared to other two models. This study shows, various numbers of meteorological parameters mostly affect the forecasting of solar radiation. The method in this paper can also be used to identify the solar energy potential of any location worldwide where it is not possible to install direct measuring instrument.

ABSTRACT. PCMs absorb a large amount of energy as latent heat at a constant phase transition temperature and are thus used for passive heat storage and temperature control applications. The present work employs a composite wall augmented with PCM for use in insulate room. Room having dimension 0.5*0.5*0.6 m3 employing PUF insulated walls with thickness 0.050 m has been made. One inner surface of the wall has been augmented using PCM, which works as a composite wall. HDPE bag is used as encapsulation material. Experiment is performed on specific days of April 2015 & May 2015 in shelter & solar radiation climatic condition. The experiment are conducted for 3 condition (1) Composite Wall without PCM (2) Composite wall with 3mm layer of PCM (0.9 Kg of PCM), (3) Composite wall with 5mm layer of PCM (1.8 Kg of PCM). In this study CaCl2.6H2O is used as PCM which has melting point is 30oC. First order implicit method is adopted to solve model of composite wall in FLUENT 15.0 Simulation results are vali-dated against experiment.

ABSTRACT. Severe mechanical degradation associated with huge volumetric change (>300%) during lithiation/de-lithiation still remains the major challenge in practical implementation of Si as an anode material for higher energy density Li-ion batteries. Such large dimensional changes cause huge stress development leading to fracture/delamination/loss of contact with current collector and also instability of SEI layer, all leading to drastic capacity fade and poor efficiency. To solve these issues, attempts have been made to use graphene as mechanical reinforcements/buffer [1,2]. More recently, shape memory alloys like NiTi have also been tried as buffer material [3]. However, as of now there is no report on experimental determination of the stress developments in the presence/absence of such buffer layer and any scientific understanding on their possible roles/effects. Hence, in this work, we have used continuous Si/graphene and Si/NiTi multilayered films as model materials and monitored the stress developments in them in-situ using multi-beam optical stress sensor (MOSS) [4] during lithiation/de-lithiation in custom-made electrochemical cell, in comparison with that for just Si film electrodes. For the Si/graphene electrodes, the multilayer graphene (MLG, 7-10 layers) was deposited via CVD technique, whereas for the Si/NiTi electrodes, NiTi (~ 100 nm) layer was deposited via pulse layer deposition technique, followed by Si deposition (~ 250 nm) by hot-wire CVD process. Marginal reduction in the lithiation induced stress developments (normalized by the corresponding Li-capacities) were recorded in the presence of the MLG and NiTi buffer layers, confirming their role as mechanical buffer. Attempt is being presently made to improve the buffering efficiencies by optimizing the electrode architecture and film thicknesses. Furthermore, SEM observations at different states of charge, along with the in-situ stress data, has allowed the development of more comprehensive understanding on the effects of the presence of such buffer layers on the stress developments and electrochemical behavior.

ABSTRACT. This paper proposes a current fed converter full bridge isolated DC-DC converter with voltage multiplier and active clamp circuit for fuel cell grid connected applications. The proposed converter is best suited for fuel cells and their interfacing to utility three phase grid. Active clamp concept introduced on the primary side of isolation transformer to reduce the turn-off voltage spikes of full bridge active devices. The proposed converter uses leakage inductance of high frequency transformer and parasitic capacitance of the active MOSFETS to achieve inherent soft- switching with extended range. Zero Voltage Switching (ZVS) is achieved for all the primary devices which allow greater switching frequency operation and improvement in over-all efficiency of the converter for utility interface. Cost, size and weight of the converter minimizes for the higher switching operation of the converter. The proposed converter implemented with half-wave Cockcroft-Walton Voltage Multiplier (H-W C-W VM) for minimal number of multiplying stages for getting required DC-link voltage for three phase utility grid connection. The converter operating switching frequency is maintained at 100 KHz. This paper organized with introduction, steady state operation, simulation results with two different cases full load and half load conditions and finally a 250 Watt experimental setup was tested with the proposed converter and the results are validated

ABSTRACT. The surface modification tendency and broad electrochemical window of carbon nanomaterials have made them widely accepted in applications like catalyst support or anode material in fuel cell, electrode in Li or Na-ion battery, nanoelectronic devices and supercapacitors etc. The performance of carbon nanomaterials always improve in presence of chemical dopants like nitrogen, boron, phosphorous mainly due to improved electrical conductivity of the material. However, high synthesis temperature (~1100°C) always restricts them to use as commercial products. In this study, a scalable and economic method is demonstrated to synthesis N-doped carbon nanoworm by chemical vapor deposition (CVD) using cashew nut shell liquid as precursor and ammonia as carrier gas and N source which is successfully used as anode material for sodium-ion battery. To the best of our knowledge, first time we are reporting carbon anode synthesized at 850ºC within 1hr which is comparatively lower temperature as well as rapid than usual methods. Wall thickness of as prepared nanoworm is ~10 nm. The unique morphology includes high pore to surface ratio which helps to store more Na-ion in its pores by providing more space to them. Further experimental findings in this regard will be discussed to understand detailed morphological stability and sodium-ion storage mechanism into it.

ABSTRACT. Various nanostructures of Titania (TiO2) play a significant role in the performance of dye sensitized solar cells (DSSC) and affect the overall light harvesting efficiency of the cells. In this article we present the one dimensional nanostructure of TiO2(nanobelts) can increase the light scattering effect, light harvesting effect and electron transport in the DSSC to improve its performance. Pure anatase TiO2 nanobelts were synthesized by a hydrothermal method using commercial material (P25) and characterized by UV-Vis, XRD, SEM, TEM and HRTEM. Cu2ZnSnS4 (CZTS) nanoparticles have been prepared by thermal decomposition method used as counter electrode material instead of platinum. DSSC have been fabricated by using a new type of double layered photoanode, which was prepared and optimized by using TiO2 nanoparticles as the main layer and TiO2 nanobelts as the over-layer (scattering layer). The photoelectric conversion efficiency (PCE) of the prepared cells was measured by solar simulator under 1 sun illumination (100 mW/cm2, AM 1.5). The DSSCs with CZTS nanoparticles based counter electrodes without scattering layer relatively low (PCE) of 5.76 %. However, the PCE was clearly improved with scattering layer and a maximum PCE of 7.85% was achieved.

ABSTRACT. Biogas from agricultural waste is a key solution for green energy and clean environment. The main focus of this work was on the production of biogas from water hyacinth. Water hyacinth grows rapidly in the catchment of river, lake and open water canal. The presence of water hyacinth in the river deteriorates the quality of the water. The batch type biogas plant was design, develops and fabricated for biogas production. The experimentation on anaerobic digestion of water hyacinth and kitchen waste was carried out. The water hyacinth was chopped, crush and mixed with water before entering into the digester. The biogas production was started in 4 days after sealing of the plant. The biogas samples were analyzed using thermal conductivity type gas chromatograph. The biogas from water hyacinth consist of 58% CH4 and 45% CO2. The biogas production was measured on daily basis. The produced biogas can be used as clean fuel for cooking or water heating application.

ABSTRACT. The photovoltaic (PV) system is capable of producing electrical energy and maintaining sustainability in the environment. In future, these energy generating systems which do not affect the environment will play a major role in building a nation. Photovoltaic system is a sustainable energy source, acts as a vital system in reducing the environmental pollution and it is called as a clean energy source. In this paper, the performance of various PV cell materials like mono-crystalline, poly-crystalline, and black solar cell are analyzed. The operating parameters of solar PV cell like parasitic resistances of series and shunt and photo-generated current are affected due to temperature. In that mono-crystalline module of 250W of shunt resistance values, poly-crystalline of 3kW (mono-crystalline manufactured by yingli’s) system in series resistance and black mono-crystalline type of 250 W and 3 kW of photo-generated current is highly influenced and changed their outputs with the effect temperature. The theoretical parasitic resistances are calculated through the simplified technique by using Lambert W function. These theoretical investigation results are compared with experimental results of 3 kW poly-crystalline solar PV modules. The influence of such resistance on the performance of the system is also analyzed.

ABSTRACT. The paper reports the thermal performance of heat pipe module with paraffin and paraffin based nanocomposites as energy storage material (ESM) for electronic cooling. The adiabatic section of heat pipe is covered by the phase change material (PCM) stored in a container made of acrylic material. Here, paraffin is used as phase change material (PCM). PCM can absorb and release thermal energy depending upon the fluctuations in the heating load. Tests are conducted to obtain the temperature distributions in PCM during charge/discharge processes. Present study utilizes two different ESM (paraffin and nanocomposite) and different working fluid for heat pipe (water and nanofluid) in the cooling module. The addition of CNTs in paraffin stores more higher amount energy compared pure paraffin material for same operating conditions.The cooling module with nanofluid charged heat pipe and paraffin as ESM found to save higher fan power consumption fan power compared to the cooling module that utilities only a heat pipe.

ABSTRACT. A boost dc-ac inverter is one which is capable of generating in a single stage ac voltage whose peak value can be higher or lower than the given input dc voltage. The major problem with this system is that the closed loop gain parameters kp and ki have to be optimized because these parameters help us to get desired result with better system response by lowering the rise time, settling time, peak overshoot and steady state error. Moreover when they are not optimized load line disturbances arise because of which the stability of output voltage decreases and THD value increases. So to overcome these difficulties bacterial foraging algorithm is being used.

ABSTRACT. Compared to the conventional graphitic anode, Sn has emerged as the promising anode material for the Li-ion batteries because of higher volumetric and gravimetric capacity. Upon lithiation of Sn, various inter-metallic Li-Sn phases like Li2Sn5, LiSn, Li7Sn3, Li13Sn5, Li7Sn2, and Li22Sn5, are known to form. In present work we reveal the yet unexplored several new phases of Li-Sn that are thermodynamically stable at ambient and high pressure conditions. Interestingly, we discovered the most Li-rich phase, Li10Sn2, that can store 5 Li-atoms for each Sn as compared to the known maximum lithiated phase of Li-Sn, i.e., Li22Sn5, which can store 4.4 Li atoms per Sn atom. Our study can help to understand the lithiation of Sn anode in a better way and thus, can provide a new dimension in the research of Li-Sn batteries.

ABSTRACT. ZnO thin films recently playing major role in photovoltaic devices. On search of doping elements for ZnO, ZnO thin films were prepared with Tin (Sn) as the dopant by sol gel-spin coating. The Sn doped ZnO thin films were fabricated with various concentrations of Tin chloride . These structural properties from XRD studies showed the influence of Sn 4+ incorporation in the Zn 2+ ion. The average particle size of Sn doped ZnO thin films has been found to increase at higher spin rates. High transmittance of 88 % was observed for the film doped with 0.005 mol % of dopant and its band gap was 3.1 eV. The Photoluminance spectra and FTIR studies of the thin films were reported. The SEM micrographs of Sn doped ZnO thin films showed that the surface morphologies of the films are influenced by the introduction of dopant. The resistivity of the Sn doped films exhibited a lower value of sheet resistance 150 MΩ/sq-cm. The results reported leads to use tin as dopant for ZnO thinfilms for solar cell applications.

ABSTRACT. Layered sulphide based materials so called LMC (layered metal chalcogenides) are promising candidate for energy storage devices, solar cells, electronics, optoelectronics because of its high capacity, good conductivity and optical band gap of 1.38eV. Also, these materials in lower dimensions can be prepared from easily available materials. LMCs are very promising electrochemical energy storage materials as they have high van-der Wall’s gap between chalcogenides layers which helps to store high capacity. Among mono-sulphides tin(II) sulphide is one of the most studied system. However, it is difficult to synthesise phase pure SnS as it always contains SnS2 as minor impurity. In this particular work, SnS nano-particles has been synthesised wet chemically taking SnCl2.2H2O (tin(II) chloride as Sn source and C2H5NS (thioacetamide) as S source in aqueous triethanolamine where ammonia is used to control the pH of the solution at room temperature. This step produces SnSx (x>1) which is bath sonicated with occasional stirring for 20 minutes for preventing the particles from agglomerating, followed by washed, dried and annealed at 500°C in N2 atmosphere for 1 hr to obtain nearly phase pure SnS. In our best knowledge, first time we are reporting a quick and easy reproducible synthesis of SnS via solution-based path. It has been observed that the average particle size lies in the range of 30 to 60 nm. Couple of experimental finding in this regards will be discussed to understand the phase purities of synthesised SnS nano-particles.

ABSTRACT. Among various types of alternative high-temperature (120-180°C) polymer electrolyte membranes developed so far, Phosphoric Acid (PA)-doped polybenzimidazole (PBI) has been reported as a promising candidate for a low-cost and high performance fuel cell membrane material. This paper presents the detailed theoretical investigation on the performance of a high temperature proton exchange membrane fuel cell (HT-PEMFC). A three dimensional non isothermal model has been used to simulate the cell performance. The developed model assumes the local interfacial equilibrium between the gas and membrane phases of water The parameters studied included operating cell temperature, operating pressure, cathode side relative humidity, cathode side stiochiometric ratio, doping level, and gas diffusing layer (GDL) porosity. The model predictions have been validated with the experimental results from literature. The new value of exchange current density is found out to be 0.5 A/m2.

ABSTRACT. Metallic anode materials are expected to replace the presently used graphitic carbon based anode materials for Li-ion batteries on accounts of their higher Li-capacities and improved safety aspects. However, the metallic anode materials experience huge volume changes during lithiation/delithiation which leads to the development of stresses that result in severe mechanical degradation and concomitant drastic capacity fade. Furthermore, the stresses affect the thermodynamics of the lithiation/delithiation ‘reactions’ and exert influences on the various electrochemical behaviour. In order to develop better understanding of the origins, magnitudes and resulting effects of the stress developments, in correlation with the initial stress states, crystallographic orientations, stages of lithiation/delithiation, associated phase transformations and surface reactions, we have monitored the stress developments in-situ during lithiation/delithiation. Sn and Al have been selected for the present studies, with the concerned electrodes possessing simple thin film architectures, sans binder/additive/porosity, to aid better understanding. The active electrode films are of ~ 100 nm in thickness, deposited via e-beam deposition, on Cu (for Sn and Al), Ni (for Sn) or Ti (for Sn) current collector films (~ 100 nm) on thick (~ 0.5 mm) and stiff quartz substrates for allowing monitoring the stress developments via substrate curvature technique using multi-beam optical stress sensor (MOSS) in-situ during electrochemical cycling against Li metal in custom-made electrochemical cell. In addition to the expected results of compressive stress developments during lithiation and reverse during delithiation, the stress results consistently provided evidences for stress release/reversal just during the regimes corresponding to the first order phase transformations between the various Li-Sn and Li-Al intermetallics. As will be demonstrated, such interesting observations suggest occurrences of mechanical degradation just during the phase transformations, with the electrode materials being fairly stable during the single phase (solid solution) regimes. In order to assess the influences of the initial stress states (i.e. prior to cycling), the residual stresses in the films have been engineered via suitable heat treatments. Carefully planned experiments with such films have highlighted the importance of the initial conditions on aspects related to cycle life and overpotentials. Such aspects get better discerned with the help of Al film electrodes, where the molar volume change associated with the Al to LiAl phase transformation is significantly higher compared to those for the other electrode materials. Additionally, the influences of different current collectors (Cu, Ni and Ti) on the crystallographic orientation, various electrochemical behaviour and stress developments will also be highlighted. It is believed that the understandings developed as part of the present work will contribute towards successful developments of electrode materials based on alloying reactions.

ABSTRACT. Solar PV generating systems have two major issues. First is low conversion efficiency of solar cell and second is presence of highly non-linear I-V characteristics. Due to dependence of characteristics of solar module on temperature and insolation, problem becomes worse. Due to changes in environmental conditions and non uniform irradiance caused by PSC, the P-V characteristics of photovoltaic arrays exhibit multiple maxima. Conventional MPPT techniques operate well under uniform irradiation but they are unable to track the global maximum point during PSC. In this paper, maximum power point tracking (MPPT) based on modified firefly algorithm (FA) for the solar photovoltaic (PV) systems operating under non-uniform irradiance is proposed. Proposed method can be applied to either standalone or grid connected systems. Advantages of the proposed method are simple steps for computation, fast tracking when meteorological conditions change and guaranteed convergence. The proposed method is studied for a particular configuration under partial shading condition and the tracking performance is obtained by MATLAB simulation and results are validated by experimental setup.

ABSTRACT. The solar photovoltaic based agricultural water pumping system is best suited technology for irrigation of farms. The generation of electrical power from Photovoltaic cell is mainly dependent on solar irradiations at respective times. The study reported in this paper deals with characteristic study of existing water pumping system based on solar photovoltaic power and conventional electrical power. Thin film Cd-Te solar panels were used to power 2HP existing water pump. The performance of solar powered water pump was as equal as pump powered by conventional one. The efficiency of solar based water pump is much higher than conventional power based water pump. The maximum flow rate obtained was 69 LPM against 65 LPM for conventional power method. MPPT was used to track best operating point of solar PV array. The outcomes of reported study are important making socio-economic impact on Indian agricultural sector.

ABSTRACT. The performance enhancement of the solar devices is dependent on the accurate functioning of the solar tracking mechanism. The solar tracking mechanism operates in single or dual mode based on axis and orientation of solar devices. The accurate tracking angle of the solar tracker is executed by the maintaining the incidence angle of the solar devices. It is necessary to optimize the incidence angle of the solar tracker. In this work, the tilting angle of the solar devices is studied with five cases i.e., (i) horizontal surface (β=00), (ii) fixed surface(β = ф, γ=00), (iii) Zenith angle tracking (β = θz,γ=00),(iv) azimuth angle tracking (β=ф, γ=γs), and(v) dual axis tracking (β=θz, γ=γs). For the above five cases, the incidence angle has been generated for the dates of summer solstice (June 21st ), winter equinox (September 21st ) and then winter solstice (December 21st ). The instantaneous position (09.00 AM, 1.00 PM and 03.00 PM) of incidence angle is compared to select the best tracking practice.

ABSTRACT. BaCe0.4Zr0.4Y0.2O3-d(BCZY) has sufficient chemical stability and protonic conductivity to be used as electrolyte material for Proton conducting ITSOFC. But its application is limited by the YSZ phase separation during long high temperature heating for sintering purpose. In this work the sintering property of BCZY has been explored and its dependence on synthesis route has been evaluated. For this purpose, BCZY has been prepared by the co-precipitation and solid –state reaction route and characterized for phase purity. The samples heated at 1300 °C exhibit stabilisation of cubic symmetry of BaZrO3 structure. The sintering behaviour of these materials has been evaluated by employing SEM. Role of atmosphere and co-pressing with NiO-BCZY in enhanced sintering behaviour has also been evaluated

ABSTRACT. Abstract: Barium indate (Ba2In2O5) is known to be a good proton conducting oxide at moderate temperatures. Thermal stability of Ba2In2-xMoxO5+y (x = 0.0–0.6) in CO2 atmosphere was studied using Thermogravimetry(TG) with evolved gas analysis and x-ray diffraction techniques. Hydrated molybdenum substituted barium indate compounds were synthesized and their chemical stability was evaluated using Thermogravimetry. As moybdneum content increases the hydrated composition of the above oxides becomes more stable.