N 2 O emission factors in bubbling fluidized bed incineration of municipal sewage sludge: The China case

The N O emissions resulting from sludge incineration are estimated using the default values published by the Intergovernmental Panel on Climate Change (IPCC), which may differ significantly from the actual emissions. In this investigation, N O emissions from four sludge incineration lines in two plants were monitored for varying durations. The variation in N O emission factors (EFs) between incineration lines of the same plant was much smaller than the difference between different plants. Data on N O EFs obtained from brief monitoring may contain variabilities of up to 30%. N O EFs were more sensitive to temperature changes at low temperatures, necessitating extended monitoring periods to improve the reliability of N O monitoring outcomes in cases of low furnace temperatures. Excessive use of the SNCR system to reduce NOx emissions resulted in concentrations of N O and NH in the exhaust gases exceeding NOx levels. In the case of furnace temperature control and advanced reburning technology, it is advisable to utilize actual monitoring data or the smaller default values provided by the IPCC in China. Otherwise, the estimated N O emissions may exceed the actual emissions.