Life-cycle assessment (EASEWASTE) of two municipal solid waste incineration technologies in China

Abstract

The environmental profile of two municipal solid waste incineration (MSWI) technologies with semi-dry flue gas cleaning, namely grated firing incinerators (GFI) and fluidised bed incinerators (FBI) that are commonly used in China were evaluated and compared by life-cycle assessment (LCA) using the EASEWASTE model. All emissions of key pollutants as well as energy, resource and material inputs and outputs associated with the two MSWI technologies were determined and the corresponding environmental impact potentials were modelled. Incineration of MSW with a lower heating value (LHV) around 4.5 MJ kg^—1 demands that auxiliary fuel is used, and both GFI and FBI caused environmental loads by contributing with environmental impact potentials in most categories except for some saving in global warming (GW100) and hazardous waste (HW). Coal combustion in FBI is a main contributor to the environmental impact potentials and thus should always be limited to a minimum. Auxiliary fuels can be avoided when the LHV of MSW is higher than 5—6 MJ kg^{— 1}. For all scenarios, GFI saves more global warming potentials than FBI due to its higher net power generation from combustion of MSW itself. Leachate from the bunker could be sprayed into the furnace for evaporation under high temperature, as an alternative to waste-water treatment, without major changes in the environmental profile of the incinerator. The presented evaluations may contribute to a more balanced environmental assessment of the two incineration technologies with respect to incineration of MSW with low heating values as often found in Asia and China.