A finite element model for char production through pyrolysis of a single biomass particle

摘要

Pyrolysis can convert biomass into non-condensable gases, condensable liquid (tar or bio-oil) and solid char. To date, most studies have focused on the optimization of process conditions for producing bio-oil that can be used as a substitute of fuel oil in boilers and turbines, or be upgraded into transportation fuels. In contrast, the char fraction is often considered a waste product that is usually combusted to provide heat for the pyrolysis process. Recently, char from biomass pyrolysis has received increasing attention for its potential use as a soil amendment or as a precursor for making catalysts and contaminant adsorbents.[1] Industrial production of char through biomass pyrolysis usually handles woodchips and pellets with a large size in the range of several centimeters. Complex chemical (pyrolysis reactions) and physical (heat and mass transfer, intraparticle gas flow) phenomena occur at this centimeter-sized particle scale. However, knowledge about these complex phenomena at the particle scale is still limited. The purpose of this work is to study the coupled chemical and physical phenomena at the particle scale for optimizing the production char through biomass pyrolysis.