环丁砜对裂解汽油一、二段加氢催化剂的影响

Effects of sulfolane on performance of catalysts for two stages hydrogenation of pyrolysis gasoline

在固定床反应装置上考察了环丁砜对裂解汽油一、二段加氢催化剂加氢性能的影响,结果表明,环丁砜对裂解汽油一段Pd系与Ni系加氢催化剂基本没有毒害作用,原因是环丁砜的硫原子最外层电子结构处于稳定状态,不存在孤对电子,无法向活性金属d空轨道提供电子,故不会在催化剂活性组分Pd、Ni中心发生吸附;当环丁砜质量分数>100μg/g时,则会降低二段Mo-Co-Ni加氢催化剂脱硫效率,这是因为随着原料中总硫质量分数的升高,必然增加脱硫难度,但通过提高入口反应温度可迅速使产品合格。

The effects of sulfolane on the performance of catalysts for the first stage and second stage hydrogenation of pyrolysis gasoline are investigated with a fixed-bed reactor.The results show sulfolane has hardly toxic effect on activity of Pd-based or Ni-based catalyst for first-stage hydrogenation of pyrolysis gasoline. The possible reason is that the outermost orbital electronic structure of sulfur atom in sulfolane is in a stable condition without lone pair electrons,which is not able to provide electrons to empty d orbit of active metal.Therefore,the active sites of Pd or Ni,active ingredients of catalyst,cannot adsorb sulfolane,and then cannot be poisoned.The desulfurizing efficiency of second-stage catalyst（ MoCo-Ni） decreases when the content of sulfolane exceeds 100 μg·g-1.This is because rising of the content of total sulfur is bound to increase difficulty of desulfurization. However,increasing reaction temperature at the entrance can solve this problem and qualified product is quickly obtained.