Experimental study on characteristics of combustion after gasification used air-steam to rice husk

To solve the slagging and tar in biomass thermochemical utilization, the method of the crude syngas combustion after low-temperature gasification was proposed. Experiments of combustion after gasification to rice husk were taken by changing equivalence ratio of agent (α_ag) and the ratio of steam to air (S/A) on the self-designed experiment bench. Temperatures of the point which was 500 mm over the vibration grate in the gasifier and the flame front in furnace were measured by thermocouples respectively; the volume percentage of syngas was also measured under different conditions by an off-line gas chromatograph (SP-3420A) which was set at 1000 mm over the vibration grate. The results of the experiments show: The gasification temperature increases when increases and S/A declines, while the temperature of the flame front decreases with and S/A increases. The volume percentage of H₂ reaches maximum value when α_ag is 0.35 and S/A is 0.10. The volume percentage of CO increases as α_ag increases, while the increasing trend gradually decreases. The volume percentage of CH₄ decreases when ER-ag increases and S/A decreases, respectively. The results of this paper provide basis and reference for the design and running of combustion after gasification system to biomass.