Seo JW  Kim YH

Vol. 27,  No. 4, pp. 350-358, Dec.  2021
10.7464/ksct.2021.27.4.350

Solid Refuse Fuel (SRF) Selective Non-Catalytic Reactor (SNCR) NOx Urea Emission factor (EF)

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The results of this study shows that the combustor temperature ranged from 848.27 to 1,026.80 ℃, averaging about 976.61 ℃, and the NOx concentration increased as the temperature increased. The urea usage ranged from 291.00 to 693.00 kg d-1, averaging about 542.34 kg d-1, and the NOx concentration decreased as the urea usage increased. Residence time was about 3.38 to 9.17 s, averaging about 5.22 s, about 2.61 times larger than the 2 s of the design details. This is 1,086 kg h -1, averaging about 55.71%, compared to the 1,950 kg h-1 SRF input permission standard. The combustion chamber area is constant, but the residence time is shown to increase with the decrease of exhaust gas. The O2/CO ratio was 847.05 to 14,877.34, averaging about 3,111.30, and the NOx concentration slightly increased as the O2/CO ratio increased. As the combustor temperature and O2/CO ratio increased, the combustion reaction with nitrogen in the air increased and the NOx concentration slightly increased. As the urea usage and residence time increased, the NOx concentration decreased slightly with an increase in reactivity with NOx. The NOx concentration at the stack ranged from 7.88 to 34.02 ppm with an average of 19.92 ppm, and was discharged within the 60 ppm emission limit value. The NOhx emission factor was 1.058 to 1.795 kg ton-1, averaging about 1.450 kg ton-1. This value was about 24.87% of the maximum emission factor of 5.830 kg ton-1 of other solid fuels. Other synthetic resins and industrial wastes were 79.80% and 43.65% compared to 1.817 kg ton-1 and 3.322 kg ton-1, respectively. This value was similar to 1.400 kg ton-1 of RDF in the NIER notice (2005-9), 10.98% compared to the maximum SRF of 13.210 kg ton-1. Therefore, the NOx emission factor had a large deviation.