Incineration is an effective way of treating Municipal Solid Wastes (MSW); however, the emission of toxic metal compounds is an issue of environmental concern. To understand the behaviour of heavy metals originally contained into MSW, an on-grate bed combustion model has been developed for simulating MSW incineration. It describes most of the physico-chemical and thermal phenomena occurring during waste combustion: gas flow, heat and mass transfer, drying, pyrolysis, combustion of pyrolysis gases, combustion and gasification of char, bed mixing, etc. The results of this bed model were used as inlet boundary conditions to perform 3D simulations of the post-combustion zone and of the heater of Strasbourg (France) incineration plant. The calculation were performed using the CFD code FLUENT. Finally, the local thermal conditions as well as the local elementary compositions of gas and solids phases obtained from these simulations were used to carry out thermodynamic calculations of the speciation of heavy metals during incineration at each point of the incinerator.
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