A Gcncralizxd Biomass Pyrolysis Model Based on Superimposed Cellulose , IIemi -

AIEWRACT-The pyrolysis of general biomass materials is modeled via a superposition of cellulose, hcmiccllulosc and lignin kinetics. All three of the primary biomass components arc modeled with multi-slcp kinetics involving both compcte-tivc primary pyrolysis and secondary tar decomposition reactions. Only " typical " (untreated) fccdstocks arc considered at at mosphcric pyrolysis pressures. The kinetics schcmc is then coupled to the porous particle model of Miller and Bcllan (1 996) along will] appropriate properties and heats of reaction to provide a cotnplctc model for the pyrolysis of arbitrary biomass fccdstocks and satnplc sizes. Comparisons with past isothermal and thcrmogravimct~ cxpcrimcnts for a variety of biomass materials under both kinetically controlled and diffusion limited conditions show favorable agrccmcnt with the model predictions. In additiolk discussions arc provided which support the usc of compctctivc char production kinc~ics over sing]c and successive reaction schcmcs which cannot currently bc reconciled with observed pyrolysis behavior. A Frequency constant. C Specific heat. c1 Characteristic pore length scale.