The Reactivity for the SO_2 Reduction with CO and H_2 over Sn-Zr Based Catalysts

摘要

The SO_2 reduction using CO and H_2 over Sn-Zr based catalysts was performed in this study.Sn-Zr based catalysts with Sn/Zr molar ratio(0/1,1/4,1/1,2/1,3/1,1/0)were prepared by the precipitation and co-precipitation method.The effect of the temperature on the reaction characteristics of the SO_2 reduction with a reducing agent such as H_2 and CO was investigated under the conditions of space velocity of 10,000 ml/g_(-cat)h,[CO(or H_2)]/[SO_2] of 2.0.As a result,the activity of Sn-Zr based catalysts were higher than SnO_2 and ZrO_2.The reactivity for the SO_2 reduction with CO was higher than that with H_2,and sulfur yield in the SO_2 reduction by H_2 was higher than that by CO.The reactivity for the SO_2 reduction with H_2 was increased with the reaction temperature regardless of Sn-Zr based catalyst with a Sn/Zr molar ratio.SnO_2-ZrO_2(Sn/Zr=1/4)had highest activity at 550 deg C,in the SO_2 reduction with H_2 and SO_2 conversion of 94.4% and sulfur yield of 66.4% were obtained at 550 deg C.On the other hand,in the SO_2 reduction by CO,the reactivity was decreased with the increase over 325 deg C.At the optimal temperature of 325 deg C,SO_2 conversion and sulfur yield were about 100% and 99.5%,respectively,in the SO_2 reduction over SnO_2-ZrO_2(Sn/Zr=3/1).Also,the SO_2 reduction using syngas with CO/H_2 ratio over SnO_2-ZrO_2(Sn/Zr=2/1)was performed in order to investigate the application possibility of the simulated coal gas as the reductant in DSRP.As a result,the reactivity of the SO_2 reduction using syngas with CO/H_2 ratio was increased with increasing the CO content of syngas.Therefore,it could be known that DSRP using the simulated coal gas over Sn-Zr based catalyst is possible to be realized in IGCC system.