Co-gasification of High-ash Sewage Sludge and Straw in a Bubbling Fluidized Bed with Oxygen-enriched Air

Gasification is a promising technology to utilize solid wastes. Co-gasification of high-ash sewage sludge and straw were studied in a fluidized bed using oxygen-enriched air. Several factors influencing co-gasification performance were investigated, including the blending ratio of straw (BR, 0-100 %), the oxygen percentage of enriched air (OP, 30.2-50 %) and the bed material type (high alumina bauxite, calcined dolomite and olivine). The results indicated that the proper increase in BR led to higher syngas yield and an increase in OP caused an increase in combustible gas components, both showing improvements for waste gasification. Correspondingly, the maximum cold gas efficiency was obtained at BR of 50 % and OP of 44.7 %, respectively. Additionally, calcined dolomite exhibited the maximum advantage in the reduction of heavy polycyclic aromatic hydrocarbons (PAHs), promoting the production of H-2 and CO. The addition of high alumina bauxite was favored for improving syngas yield and gasification efficiency.