순산소연소는 높은 연소 효율과 적은 배가스량, 낮은 질소산화물 농도를 장점으로 하고 있으며 연소온도 조절을 위한 배가스 재순환에 의해 배출되는 연소가스중의 CO2 농도를 95%까지 농축이 가능하므로 석탄 연소설비에 대한 유망한 CCS 기술로 부각되고 있다. 본 연구는 순산소연소 조건에서 배가스의 재순환을 통한 CO2 농도 증가에 기인하는 직접 황화반응이 탈황효율에 미치는 영향을 평가하고 반응온도, CO2 농도, SO2 농도상승이 SO2 제거효율에 미치는 영향과 배가스 중 수분 등이 SO2 제거효율에 미치는 영향을 실험적으로 고찰하였다. 반응온도 1,200 ℃까지 온도 상승에 따라 SO2의 제거효율은 증가하였고 Ca/S비, CO2 농도와 수분이 증가할수록 SO2 제거효율이 증가하였다. 이러한 운전변수는 영향인자 평가를 통하여 Ca/S 비>체류시간>O2농도>반응온도>SO2농도>CO2농도>수분농도의 순으로 탈황반응에 영향을 미치는 것으로 나타났다. 또한 운전변수별 실험결과를 이용하여 로내 건식탈황에 있어서 각 운전변수별 성능 영향인자를 평가할 수 있는 반경험적 모델식을 도출하였다.

Oxy-fuel combustion with many advantages such as high combustion efficiency, low flue gas flow rate and low NOx emission has emerged as a promising CCS technology for coal combustion facilities. In this study, the effects of the direct sulfation reaction on SO2 removal efficiency were evaluated in a drop tube furnace under typical oxy-fuel combustion conditions_x000D_ represented by high concentrations of CO2 and SO2 formed by gas recirculation to control furnace combustion temperature. The effects of the operating parameters including the reaction temperature, CO2 concentration, SO2 concentration, Ca/S ratio and humidity on SO2 removal efficiency were investigated experimentally. SO2 removal efficiency increased with reaction_x000D_ temperature up to 1,200 due to promoted calcination of limestone reagent particles. And SO2 removal efficiency increased with SO2 concentrations and the humidity of the bulk gas. The increase of SO2 removal efficiency with CO2 concentrations showed that SO2 removal by limestone was mainly done by the direct sulfation reaction under oxy-fuel combustion conditions._x000D_ From the impact assessment of operation parameters, it was shown that these parameters have an effects on the desulfurization reaction by the order of the Ca/S ratio > residence time > O2 concentration > reaction temperature > SO2 concentration > CO2 concentration > water vapor. The semi-empirical model equation for to evaluate the effect of the operating parameters on the performance of in-furnace desulfurization for oxy-fuel combustion was established.

Oxy-fuel Combustion In-Furnace Desulfurization Limestone Calcination Sulfation

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