Experimental Study on Autothermal Cyclone Air Gasification of Biomass

Abstract

Cyclone gasification technology is commonly used for biomass fuels with small particle sizes, such as rice husks and wood chips. This paper explored the effects of gasification intensity and equivalence ratio on the performance characteristics of an autothermal cyclone gasifier. Increasing the gasification intensity caused the syngas' heating value, the cold gasification efficiency and the carbon conversion rate to increase to a maximum for an intensity of 885.24 kg/(m2 h) before then decreasing as the gasification intensity was further increased. Increasing the equivalence ratio from 0.23 to 0.32 increased the overall temperature of gasifier, decreased the tar content (from 6.84 to 4.96 g/N·m3), and increased the carbon conversion rate (from 47.2% to 62.3%). Increasing the equivalence ratio to 0.26 also increased the syngas' heating value to its maximum of 4.25 MJ/N·m3, which then decreased with further increases in equivalence ratio. A similar trend was observed for the gasification efficiency, which ranged from 30% to 37%. From these tests, a gasification intensity of 885.24 kg/(m2 h) and an equivalence ratio of 0.26 appeared optimal for the autothermal cyclone air gasification of biomass process studied here.