Co-Combustion of Municipal Solid Waste and Thai Lignite in a Fluidised Bed

Experimental investigations on the co-combustion characteristics of high-moisture municipal solid waste (MSW) and high-sulphur Thai lignite were carried out using a laboratory scale fluidised-bed reactor. The objective is to study the effect of main operating parameters on the combustion characteristics and gas emissions. The results show that the co-combustion characteristics differ significantly from the combustion of lignite alone. The co-combustion of MSW and lignite reduces the emission of SO2 while increasing NO and N2O slightly. It also results in a slight drop in combustion efficiency. The optimum condition for co-combustion of MSW with lignite, in view of carbon combustion efficiency, emissions of CO. NO and N2O appears to be the following: 20% MSW mass fraction, 40-60% excess air and 0.2 secondary to total air ratio. However, this occurs at the expense of slightly smaller reduction in SO2 emission, which could become insignificant with limestone addition in the bed. The synergistic effect of co-firing two fuels enhances the combustion reactivity and reduces NO, N2O and CO emissions