FORMATION OF DIOXINS AND FURANS DURING MUNICIPAL SOLID WASTE GASIFICATION

Abstract

Thermal treatment is an interesting strategy to dispose of municipal solid waste: it reduces the volume and weight of the material dumped in landfills and generates alternative energy. However, the process emits pollutants, such as dioxins and furans. The present study evaluated MSW gasification-combustion integrated technologies in terms of dioxin and furan emission; and compared the obtained data with literature results on incineration, to point out which operational features differentiate the release of pollutants by these two processes. The results show that the process of integrated gasification and combustion emitted 0.28 ng N-1 m-3, expressed in TEQ (Total Equivalent Toxicity), of PCDD/F, less than the maximum limits allowed by local and international laws, whereas incineration normally affords values above these limits and requires a gas treatment system. The distinct operational conditions of the two thermal processes, especially those related to temperature and the presence of oxygen and fixed carbon, led to a lower PCDD/F emission in gasification.