Fate of sulfur and chlorine during co-incineration of municipal solid waste and industrial organic solid waste

Abstract

In China, the co-incineration of municipal solid waste (MSW) with industrial organic solid waste (IOSW) is increasingly adopted. Compared with MSW, IOSW contains higher levels of sulfur (S) and chlorine (Cl), presenting significant challenges for controlling S/Cl emissions in MSW incineration plants. In this study, the impact of co-incinerating IOSW was investigated in a 500 t/d incinerator grate, focusing on the emissions and transformation behaviors of S/Cl. IOSW, with a consistent sulfur content of about 0.22 wt% and a more variable chlorine content averaging 0.53 wt%, contains over 40 % organic sulfur and >90 % organic chlorine, higher than in MSW. The results of co-incineration experiments showed that the median SO2 concentration in the flue gas was stable at 50 mg/m3, while HCl concentration decreased initially and then increased as the co-incineration ratio of IOSW rose from 20 % to 40 %. Furthermore, the concentrations of SO2 and HCl were not significantly influenced by wind flow but were positively affected by the rising furnace temperatures. Besides, the co-incineration ratio had minimal impact on sulfur in fly ash before deacidification, primarily derived from the gas stream. However, the (Na + K)/Cl ratio in fly ash progressively increased from 1.5 to 1.9, and the Ca content decreased from 0.35 % to 0.15 % as the co-incineration ratio rose to 40 %, indicating more chlorine migration into the fly ash at higher co-incineration rates. This research offers essential guidance for effectively controlling pollutant emissions during the co-incineration of IOSW, specifically the S/Cl pollutants.