A comprehensive model was developed to simulate gasification of pine sawdust in the presence of both air and steam. The proposed model was built upon the premise of an existing Aspen Plus-based biomass gasification model with select improvements. These include the addition of a temperature-dependent pyrolysis model, an updated hydrodynamic model, more extensive gasification kinetics and the inclusion of tar formation and reaction kinetics. The Aspen Plus process simulator was used in combination with a more extensive Fortran subroutine to appropriately model a Bubbling Fluidized Bed (“BFB”) gasifier. The validity of the model was compared on two fronts: Firstly, the accuracy of the model’s predictions in comparison with the actual experimental results; and secondly, the relative accuracy of the model prediction in comparison to the original base-model.