Tar formation variations during fluidised bed pyrolytic biomass conversion

A 3D Eulerian/Lagrangian simulation incorporating multi-step reaction mechanisms has been used to study fast pyrolysis of biomass in a 100 g/h fluidised bed reactor. The overall goal to optimise the production of bio-oil from fast pyrolysis is largely dependent on the thermochemical degradation process inside fluidised bed reactors. The discrete representation of biomass and sand particles in the simulation bridges accurate numerical modelling with reproducing realistic phenomena seen experimentally. Herein, the hydrodynamic bed behaviour causes temperature variations among batches of biomass particles injected at different times. It is found that such disparity affects the instantaneous tar release, causing relatively large differences in tar quantity and quality. (C) 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.