Gasification characteristics of biomass at a high-temperature steam atmosphere

Abstract

Gasification activity of seven kinds of biomass (rice husk, rice straw, maize straw, cotton straw, wood chip, coconut fiber, and chicken manure) at 900 °C with a high-temperature steam atmosphere were experimentally studied in a self-designed reactor. The effects of temperature and reaction time on the pore structure of rice husk char were analyzed. Gas chromatography and a full-automatic surface area analyzer were used to measure the composition of product gas, the specific surface area, and the pore size distribution of rice husk char. Results show that cotton straw has the highest gasification activity and needs 5 min for complete reaction. The contents of H2, CO, CH4, and CO2 in product gas are 50.77%, 21.39%, 5.51%, and 21.39%, respectively. The gasification activity of rice straw is the lowest and it needs 40 min for complete reaction. As the increasing of reaction time, the specific surface area of rice husk char decreases from 273.44m2/g to 1.33m2/g. Besides, at 500 − 800 °C, the specific surface area increases from 40.93 m2/g to 334.44 m2/g, mainly due to the generation of new micropores and mesopores, but it reduces to 1.33 m2/g at 900 °C as a result of the disappearance of micropores and mesopores.