Characterization of the physicochemical and structural evolution of biomass particles during combined pyrolysis and CO2 gasification

The combination of pyrolysis and CO2 gasification was studied to synergistically improve the syngas yield and biochar quality. The subsequent 60-min CO2 gasification at 800 degrees C after pyrolysis increased the syngas yield from 23.4% to 40.7% while decreasing the yields of biochar and bio-oil from 27.3% to 17.1% and from 49.3% to 42.2%, respectively. The BET area of the biochar obtained by the subsequent 60-min CO2 gasification at 800 degrees C was 384.5 m(2)/g, compared to 6.8 m(2)/g for the biochar obtained by the 60min pyrolysis at 800 degrees C, and 1.4 m(2)/g for the raw biomass. The biochar obtained above 500 degrees C was virtually amorphous. (C) 2017 Energy Institute. Published by Elsevier Ltd. All rights reserved.