A reactor network of biomass gasification process in an updraft gasifier based on the fully kinetic model

Modelling gasification reactors by process simulation is a practical utility to evaluate gasification performance and assist device design. In this study, a fully kinetic model for the biomass gasification process within a pilot-scale updraft gasifier is proposed, which considers the effect of reactor dimensions, residence time, and temperature distribution on the gasification process compared with the thermodynamic equilibrium method and kinetic method modeled by continuous stirring tank reactor blocks. The pyrolysis stage is defined by detailed solid biomass pyrolysis mechanisms and secondary gas reactions kinetic mechanisms. Moreover, the gas evolution effect in the pyrolysis stage is considered by transferring gas to the gasification zone and freeboard zone according to different temperatures. The gasification and combustion processes are modeled utilizing comprehensive homogeneous and heterogeneous rate-controlled reactions and the plug flow reactor is first used in modelling the updraft gasifier with the countercurrent characteristic. This proposed model is validated by several experimental data and the predictive results agree well with experimental data with the maximum root-mean-square deviation of 2.6%. The effect of air or steam as gasification agents on gasification performance is evaluated by the proposed model. This model can provide guidance for industrial equipment design.