Fluidized bed technology known for its efficient heat and mass transfer and controlled material handling, is widely used across industries. However, CFD simulation of fluidized beds presents challenges that require extensive validation. This study leverages the Multiphase Particle-In-Cell (MP-PIC) method, a recent Lagrangian modeling technique to improve computational efficiency and accuracy. The CAD model was developed using SolidWorks 2020 and simulation was carried out in the commercial CFD package Barracuda VR 21.1.0. The sensitivity of grid size, drag models and the impact of recirculating pipe height after loop seal was examined. Sand particles 63-200 μm and air were used as bed material and fluidization gas respectively achieving full flow circulation at 650 SL/min and 12 SL/min aeration in the riser and loop seal. A total of 19 different simulations were conducted, varying grid size and drag models each for a duration of 45 seconds with a time step of 0.0005 seconds. Pressure transducers along the CFB walls provided validation data. The Wen-Yu Ergun drag model showed a minimal error margin of 0.60%, followed by the Wen-Yu 80000 model at 0.62%, demonstrating high predictive accuracy.