An investigation of an oxygen-enriched combustion of municipal solid waste on flue gas emission and combustion performance at a 8 MWth waste-to-energy plant

This paper describes the effect of oxygen-enriched combustion (OEC) on the flue gas emission and combustion performance of municipal solid waste (MSW) in a full-scale waste incineration plant without flue gas recirculation. Input gas with different oxygen concentrations (21%, 24%, 27%) were supplied into the MSW grating furnace with a capacity of 150 t/d to evaluate the effect of inlet oxygen content on the emissions of NOx, NO, SO2, HCl as well as dioxins (PCDDs and PCDFs). Combustion temperature in the incinerator, unburnt rate and thermal efficiency were also examined to assess the combustion performance under OEC condition. Results showed that the amount of SO2 and HCl decreased to lower levels during OEC condition, while the average concentrations of NOx and NO increased with increase in oxygen content of input gas. Dioxins (PCDDs and PCDFs) in both flue gas and fly ash were highly increased elevated by the oxygen intake, especially for PeCDFs and HxCDFs. The average temperature in three grates of incinerator increased as oxygen concentration increased, while the unburnt rate gradually decreased, indicating a slight improvement of MSW thermal efficiency and more complete combustion under OEC condition. (C) 2019 Elsevier Ltd. All rights reserved.