Development of Ecologically Friendly Technology for Gasification of Municipal Solid Wastes

Ukraine as well as other countries all over the world has a problem of municipal solid waste utilization. One of the most popular technologies is combustion of MSW. However, MSW combustion cannot provide permissible level of harmful matters emission without very difficult and expensive gas cleaning systems. Especially it applies to polychlorinated dibenzo-(p)-dioxins and furans – global superecotoxicants, which have strong mutagenic, immunosuppressive, carcinogenic, teratogenic, and embryotoxic activity. Dioxins are always generated with presence of oxygen, chlorine, and organic compounds at high temperature (above 300°C). In the waste chlorine is mainly present in such compounds as kitchen salt and polyvinyl chloride. Existing technologies of MSW combustion do not decrease dioxin emissions with 100% effectiveness. The most powerful method of dioxin formation suppression is based on deactivating potential of its formation precursors, such as: chlorine, oxygen, and catalysts. One of possible technological approaches is gasification of chlorine-containing fuels or wastes: absence of oxygen effectively blocks dioxin formation routes. Product gas cleaning from ashes and halogens eliminates dioxin reformation after combustion. In the Institute of Technical Thermophysics the experimental fluidized bed installation for chlorine containing waste gasification is under development.