Ni-Mo/Al_2O_3催化剂上硫转移反应的研究

制备了以γ-Al2O3为载体的Ni-Mo催化剂,并用于FCC汽油的加氢硫转移反应。对Ni-Mo/Al2O3催化剂上的硫转移反应机理进行了研究,考察了不同反应条件对硫转移反应的影响。实验结果表明,硫醇与烯烃的反应在催化剂表面的加氢活性位上进行,小分子的硫醇发生加氢脱硫,生成吸附态H2S,吸附态的H2S与烯烃反应,生成大分子硫醇和硫醚;另外小分子硫醇还可直接与烯烃发生反应,生成硫醚。提高反应温度、压力、氢油比或降低空速,均可提高催化剂的硫转移反应活性,轻质硫转化率得到明显提高,且单烯选择性还能维持在98%左右。

Study of sulfur transfer reaction on Ni-Mo/Al2O3 catalyst

The bimetal Ni-Mo catalysts supported on γ-Al₂O₃ were prepared and used for the selective hydrogenation of FCC gasoline for sulfur transfer. The reaction mechanism of sulfur transfer on Ni-Mo/Al₂O₃ catalyst was studied and the influence of reaction conditions on sulfur transfer was investigated. The results showed that the reaction of thiol and olefin happened on the active sites of hydrogenation on catalyst surface. Hydrodesulfurization of small molecule thiol firstly produced adsorbed hydrogen sulfide, then the adsorbed hydrogen sulfide reacted with adsorbed olefin and formed macromolecular thiol or thioether; Besides, small molecule thiol can also directly reacted with olefins to produce thioether. The activity of sulfur transfer reaction of Ni-Mo/Al₂O₃ catalyst was improved through the increase of reaction temperature, pressure, and H₂/oil ratio or the decrease of LHSV. The conversion of light sulfur compounds was obviously improved, and mono-olefins selectivity was maintained at around 98%.