Performance evaluation of an integrated waste-to-energy plant fed by municipal sewage sludge, submitted for possible publication in

Sewage sludge processing and disposal are one of the most environmentally challenging aspects of the wastewater treatment process, due both to the continuously increasing quantities produced and to the stricter environmental rules in many countries. Recently, a growing interest towards sludge incineration has been reported in many European countries, driven by the considerable technological development of this technology, by the potential energetic aspects, and by the intrinsic limits of recycling and landfilling. The aim of this paper is to explore the technical feasibility of an integrated waste-to-energy plant fed by raw sludge and refuse derived fuel (RDF) from a medium-sized town. The proposed plant is based on a commercial steam-injected gas turbine and it includes a direct-fired sludge dryer, an incinerator and a flue gas treatment section for gaseous and solid pollutants. The thermal drying process also reduces the volume and pathogen content of sludge prior to landfilling. Performance of the integrated system appears promising in terms of energy efficiency as well as pollutant emissions. Moreover, the analysis carried out shows that the proposed integration is an attractive option for producing electricity from waste in medium size municipal applications, providing at the same time operational flexibility for catchment areas of sludge and RDF.