(587aq) Gasification of Anaerobic Digestion Sludge Using a Dual Fixed Bed Gasifier

In this study, gasification of refractory organic matters and woody biomass was investigated using a laboratory-scale dual fixed bed gasifier. As samples, white wood pellets of coniferous trees and dehydrated sludge derived from anaerobic digestion of sewage sludge were used. Wood pellets were used to improve combustion of sludge with high water content and to examine the synergy effect of co-gasification of both samples. Gasification tests were performed at different values of equivalence ratio and blending ratio of wood pellets/anaerobic digestion sludge, and the effect of these experimental parameter on gas composition, cold gas efficiency, and tar content of the producer gas was examined. In the experiment, spatial temperature profiles in the gasifier, composition of the produced gas, total volume of the produced gas and tar content were also measured. The results showed that gasification with relatively low tar for anaerobic digestion sludge content was possible using the laboratory-scale dual fixed bed gasifier when it was gasified with wood pellets.