Aqueous pyrolysis liquid (APL) is formed from pyrolysis of lignocellulosic biomass and is considered as a possible feed for anaerobic digestion (AD). APL is known to contain many components that can have a negative impact on the AD process. In this study, APL is fed into experimental AD batch reactors and modelled as a substrate using the Anaerobic Digestion Model No. 1 (ADM1), extended by addition of the inhibitors phenol, furfural, and HMF. Simulation performed with the extended ADM1 has a better ability to predict the behavior of APL than the standard ADM1. Reducing the inhibition constants and startup concentration of active biomass during simulation of APL at high organic load resulted in improved fit with experimental results, but these inhibitors alone cannot explain the reduced methane production rate at high organic load.