화학공학소재연구정보센터
HWAHAK KONGHAK, Vol.41, No.5, 572-576, October, 2003
SO2로부터 원소 황 회수를 위한 Ce1-xZrxO2 촉매반응연구
A Study of Ce1-xZrxO2 Catalytic Reaction for the Recovery of Elemental Sulfur from SO2
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초록
Ce1-xZrxO2 촉매상에서 CO에 의한 SO2의 촉매환원으로부터 원소 황 회수 반응에 대하여 연구하였다. Ce1-xZrxO2 촉매는 Ce/Zr 조성비를 x=1, 0.8, 0.5, 0.2, 0과 같이 조절하여 제조하였으며 반응온도(400-450 ℃), 공간속도(10,000-70,000 h-1)변화에 따른 SO2전화율과 원소 황(S)선택도를 조사하였다. Ce1-xZrxO2촉매의 최적반응온도는 425 ℃이었으며 공간속도 50,000 h-1에서 Ce0.8Zr0.2O2와 Ce0.5Zr0.5O2촉매의 SO2 전환율이 93%, 원소 황 선택도 98%로 CeO2, Ce0.2Zr0.8O2촉매보다 반응성이 높았다. Ce1-xZrxO2촉매에 Zr의 첨가량이 증가할수록 CeO2의 환원률이 증가되었으며, 이러한 결과는 산소 저장성이 우수하나 CeO2에 Zr를 첨가함으로써 산소이동성이 증가되었기 때문인 것으로 판단된다. 본 연구에서는 Zr의 첨가로부터 Ce-based 촉매의 격자산소 환원과 비어있는 격자산소 자리의 재산화에 영향을 주어 redox 반응특성을 개선할 수 있음을 확인하였다.
The catalytic reduction of SO2 to elemental sulfur with CO over Ce1-xZrxO2 was studied. The Ce1-xZrxO2 catalysts were prepared by changing the Ce/Zr mole ratio (x=1, 0.8, 0.5, 0.2, 0). The reactivity of Ce1-xZrxO2 in accordance with experimental conditions, such as reaction temperature (400-450 ℃), space velocity (GHSV: 10,000-70,000 h-1) were investigated. The conversion of SO2 and the selectivity to elemental sulfur in the recovery of elemental sulfur from SO2 using Ce0.8Zr0.2O2 and Ce0.5Zr0.5O2 catalysts were respectively about 93% and 98% at temperature about 425 ℃, which were superior to other catalysts. It seems that the reactivity is influenced by the Ce/Zr mole ratio. From these results, it was concluded that the oxygen mobility of catalysts was increased with inserting the Zr. Because the reduction of lattice oxygen and reoxidation of Ce-based catalysts was improved by the adding Zr, it is possible to improve the redox characteristic.