Experimental study of a down-draught fixed bed gasifier

摘要

Air gasification experiments were carried out in a downdraft gasifier with two combustion chambers. Briquettes made from different agriculture residues were used in the present study. The effects of varying excess air ratio and gasification temperature on syngas composition and heating value were investigated. The excess air ratio for the gasifier is found to be in range 0.17-0.33. The gasification temperature depends on the amount of air fed to the gasifier and therefore by the excess air ratio. An increase in the air flow rate resulted in a decrease in the concentrations of H_2 and CO and a higher CO_2 production. It has been found that the LHV of the syngas is high for low excess air ratios due to the high H_2 and CO contents.