Co-combustion of Sewage Sludge and Municipal Solid Wastes

摘要

It is expected that generation of sewage sludge is going to increase continuously and the appropriate disposal of it is needed. Although ocean dumping or landfill has mainly applied for the treatment, incineration is recently considered as one of alternative methods. Sewage sludge cannot be directly incinerated in any incinerators without auxiliary fuel because of its low heating value. Because a fossil fuel is very expensive, co-combustion with combustible wastes like municipal solid wastes (MSW) or refuse derived fuel (RDF) is recommended. However, co-combustion of sludge and MSW has some social and technical problems such as the generation rate of sewage sludge and the limit of sludge feeding ratio in MSW incinerator. The co-combustion system of sewage sludge and MSW is basically composed of 7 unit processes. Among of them pretreatment, feeding, incineration and air pollution control processes are very important to design and operate co-combustion system properly. These processes have been studied for several years in order to develop a reasonable co-combustion system for MSW incinerator and sludge incinerator. Generation characteristics of sewage sludge and co-combustion characteristics of MSW will be described in this paper with introduction of elementary technologies included in each unit process.