(122a) Co-Gasification of Sewage Sludge and Biomass in a Fixed Bed Downdraft Gasifier

Sewage sludge, an unavoidable product of municipal waste-water treatment plant, is one of the wastes that can be converted into useful energy. The amount of sewage sludge will increase considerably due to municipal development and increasing populations in cities. Currently, sewage sludge is mainly being handled via landfill, incineration or anaerobic digestion. This study investigates the co-gasification of sewage sludge with wood chips in a fixed bed downdraft gasifier. The produced syngas is to be used to generate heat and power in an internal-combustion engine. The characterization of sewage sludge and wood chips was carried out via thermogravimetric analysis (TGA), elemental analysis and Inductively Coupled Plasma (ICP) analysis. The effects of different sewage sludge fractions in the mixture with woodchips on product yields, gas composition, gross heating value and gasification performance are investigated. These results can help us better understand co-gasification of sewage sludge and biomass in a fixed-bed downdraft gasifier.