Issue
Korean Chemical Engineering Research,
Vol.43, No.2, 324-329, 2005
SNCR 공정에서 Sodium Salts 첨가제를 이용한 탈질반응 개선에 관한 연구
The Improvement of Denitrofication by Using Sodium Salts in the SNCR Process
본 연구에서 SNCR 공정에서 사용되는 NO의 농도는 500 ppm이며, 환원제로 Urea를 사용하였다. 또한 첨가제로 NaOH(sodium hydroxide), Na2CO3(sodium cabonate), NaNO3(sodium nitrate), HCOONa(sodium formate), CH3COONa (sodium acetrate)를 이용하여 온도와 첨가제에 따른 NO 저감 효율을 측정하고자 하였다. 이때의 NO 저감 온도의 범위는 650-1,050 ℃이다. 환원제만 사용하였을 경우, NO의 저감 효율은 44%까지 증가하였으며, 환원제와 첨가제(NaOH) 를 0.5 mol/L와 1 mol/L 사용하였을 경우, NO 저감 효율은 25%와 74%이상 증가하였다. 첨가제를 사용하지 않았을 경우보다 첨가제를 사용하였을 경우 NO의 저감 효율은 증가하였다. 또한 NaOH>Na2CO3>NaNO3>HCOONa, >CHCOONa 첨가제의 순으로 효율이 우수하였다. 첨가제를 사용할 경우 약 900 ℃에서 1,050 ℃의 온도범위에서 NO저감 효율이 65% 이상으로 나타났다. 온도 창의 범위는 약 250 oC의 범위로 나타났으며, 최저 효율은 약 20%이며 최대효율은 약 74%정도로 나타났다.
The efficiency of reducing nitric oxide using urea combined with alkali salt additives is reported in this study. The inlet concentration of NO is 500 ppm with air flow rates of 3 and 5 L/min. Reduction of NO was studied from 650 to 1,050 ℃ with urea concentrations of 0.3 to 1 mol/L. The efficiency for the reduction of NO increased by 44% when urea is added alone. A further increase in efficiency was observed in the presence of NaOH as additive in fact, the efficiency was increased by more than 25% and 75% when 0.5 mol/L and 1 mol/L NaOH were added with the urea. The efficiency for the reduction of NO increased with all additives, but descended in the order NaOH, Na2CO3, NaNO3, HCOONa, and CHCOONa. The maximum efficiency of NaOH and Na2NO3 are 74% and 73%, respectively. All these additives did not alter the comparatively wide operating temperature window for reducing NO. However, sodium compounds do not shift the maximum NO concentration towards lower temperatures when the NO removal activity enhances.
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