摘要:
本文研究了活性焦(AC)担载Co-Mo催化剂对SO2还原的催化性能,考查了催化剂不同的预处理方法,H2/SO2摩尔比和还原温度对还原过程硫产率的影响,并就硫化后的Co-Mo和活性焦在催化床不同的构成对硫产率的影响进行了研究,结果表明,经硫化后的催化剂对SO2+2H2→S+2H2O反应有较高的催化活性,在最佳反应温度300℃,H2/SO2摩尔比为3,空速6000 L·kg-1·h-1条件下,生成硫的产率可达85%,在Co-Mo/AC上H2对SO2的还原机理与Co-Mo/Al2O3上的相同,即反应分两步进行,首先在硫化钴和硫化钼活性相上H2将SO2加氢还原成H2S(SO2+3H2→H2S+2H2O),然后生成的H2S和气相中的SO2在活性焦活性相上发生Claus反应(SO2+2H2S→3S+2H2O),生成元素硫.
Abstract:
This paper studies reduction of SO2 to elemental sulfur using hydrogen over activated coke supported Co-Mo catalysts. The effects of presulfidation of the catalysts, H2/SO2 mole ratio and reduction temperatures on the performance of the catalysts are presented. Without presulfidation the catalysts show very low activity, the presulfidation, in a flow of 10% H2S in H2, greatly enhances the catalytic activity. For a feed with a SO2/H2 mole ratio of 1:3, a sulphur yield of about 85 % was achieved at temperature of 300℃. It was found that the SO2 reduction by H2 on Co-Mo/AC follows the same mechanism as that proposed for Co-Mo/Al2O3, that is: hydrogenation of sulphur dioxide to hydrogen sulfide on the mental sulfide phase (SO2+3H2→H2S+2H2O), and the Claus reaction between hydrogen sulfide and sulfur dioxide for elemental sulfur on the acidic sites of the AC support (SO2+2H2S→2S+2H2O).
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