Effects of feeding rate on catalytic pyrolysis of sawdust in bubbling fluidized beds

Abstract

Catalytic cracking of sawdust has been studied numerically in bubbling fluidized beds with in situ catalyst. The upgrading of bio-oil is one of the critical issues in applications of biomass pyrolysis products. Due to the interactions of multiphase flow dynamics coupled with chemical reaction, computational modelling of thermo-chemical processing of biomass can be quite complex. In current work, the online catalytic upgrading of bio-oil derived by sawdust pyrolysis is investigated. The Eulerian-Eulerian models coupled with the Kinetic Theory of Granular Flows are employed to model the multiphase flow in fluidized beds. The user defined functions (UDF) is developed based on the chemical kinetics to represent the decomposition of biomass and upgrading of bio-oil. The simulation results show that the heterogeneous reactions can perform significant effects on hydrodynamics of fluidized beds while different space time, the ratio of catalyst mass to tar flow rate, will vary the yield distribution of products.