用不同催化剂在流化床中合成甲醇

在流化床中利用合成气(V(H2)∶V(CO)=2)合成了甲醇,对比了C302,C306,LP201催化剂对甲醇合成反应的催化性能。考察了反应温度、氢碳比、CO空速对合成反应的影响;并对反应前后不同催化剂进行了X射线衍射(XRD)表征。研究结果表明,甲醇合成存在最佳的反应温度(210~250℃);增加压力,有利于CO转化率和甲醇选择性的提高,但使用不同催化剂时,甲醇选择性的变化趋势不同,相对于LP201催化剂,C302催化剂更适合较高压力,C306催化剂在低温下活性较好;甲醇的选择性与空速、氢碳比、压力均有关,提高空速、增加氢碳比均有利于提高甲醇的选择性,降低流化床中的气体返混,抑制甲醇的二次裂解。XRD表征结果表明,低氢碳比时,流化床中的催化剂无积碳。

Methanol Production in Fluidized Bed Reactor Using Different Catalysts

Methanol was synthesized from syngas over different Cu/Zn/Al2O3 catalysts in fluidized-bed reactor.Effects of different catalysts(C302,C306 and LP201),reaction temperature,volume ratio of H2 to CO and CO space velocity on the synthesis were investigated.Appropriate temperature for the synthesis is in the range of 210-250 ℃.With raising of pressure,CO conversion and methanol yield increase.For C302 catalyst both CO conversion and methanol selectivity are high in quite broad pressure range.Catalyst C306 is active at lower temperatures.Higher volume ratio of H2 to CO and higher CO space velocity are advantageous to lift methanol selectivity due to decrease of gas-backmixing in fluidized-bed.Both fresh and used catalysts were characterized by means of XRD.The result shows that even under low volume ratio of H2 to CO,non-carbon deposition forms on the catalysts in fluidized-bed reactor.