High Temperature Gasification Behaviour of Organic Waste Material in an Entrained Down Flow Gasifier

摘要

High temperature air gasification of sewage sludge was carried out in an entrained down-flow gasifier. Evaluation of gasification performance, such as gasification temperature, carbon conversion and gas composition, comparing sludge with woody biomass, was objective of this study. Pulverized sludge, sieved 60 mesh, was injected from the top of the gasifier with air, and gasification experiment conducted over 1300 K. Feeding rate of the sludge was controlled around 25 kg/h. Amount of supplied oxygen divided by amount of oxygen for complete combustion (O'/O) employed as the operation condition. Temperature distribution in the gasifier was different between sludge and woody biomass, temperature with using sludge was constant at the bottom of the gasifier; however temperature of the gasifier decreased significantly at the bottom with using woody biomass by the endothermic CO_2 gasification reaction. Due to the gasification rate of sludge was slower than that of woody biomass, carbon conversion of sludge was less than that of woody biomass, which was around 80 %, while 100 % carbon conversion achieved in woody biomass gasification. Gas composition between sludge and woody biomass insignificant, however carbon monoxide and hydrogen production of sludge became smaller than that of woody biomass at the same operation conduction.