Investigation of the intrinsic CO2 gasification kinetics of biomass char at medium to high temperatures

In total eight char samples from pelletized wood, miscanthus, and straw were prepared under various pyrolysis conditions. The CO2 gasification kinetics for each sample was established in the temperature range from 800 degrees C to 1300 degrees C by the combination of thermogravimetric analysis (TGA) and a novel aerosol-based method. The aerosol-based method was used for the high temperature range between 1100 degrees C and 1300 degrees C, by gasifying suspended char particles (0.5-10 mu m) in an oxidizing carrier gas. A tapered element oscillating microbalance (TEOM) was used to measure the change of mass concentrations of particles in the carrier gas, before and after gasification. The results showed that the aerosol-based method could be used to investigate the intrinsic gasification kinetics of biomass char, at least up to 1300 degrees C. All char samples showed similar reactivity in the low temperature range. However, above 1000 degrees C there were significant differences in reactivity, and at 1300 degrees C the conversion of the wood was in the order of 10 times faster than that of straw. The general char reactivity order in this study was wood > miscanthus > straw. (C) 2013 Published by Elsevier Ltd.