硫化物对Ni/Al2O3催化剂加氢性能的影响

在固定床反应器中考察了多种硫化物对镍催化剂上苯乙烯和环己烯加氢活性的影响。结果表明,在70 oC和1.0 MPa时,二硫化碳、二甲基二硫醚、噻吩、正丁基硫醇、二甲基硫醚都会使镍催化剂上的环己烯和苯乙烯中苯环的加氢活性降低。在硫含量相同的情况下,以上几种硫化物对苯乙烯中苯环加氢的毒性由大到小的顺序为：二甲基硫醚≈二甲基二硫醚＞噻吩＞二硫化碳＞正丁基硫醇。对于环己烯加氢的毒性由大到小的顺序为：二甲基二硫醚＞正丁基硫醇＞二硫化碳＞二甲基硫醚＞噻吩。二硫化碳是苯乙烯中共轭烯烃加氢快速失活的主要硫化物。随着二硫化碳含量的增加,苯乙烯中共轭烯烃加氢活性下降程度增大；随温度升高,其加氢活性下降程度减小。

THE EFFECT OF SULFIDES ON THE HYDROGENATION PERFORMANCE OF Ni/Al2O3 CATALYST

The poisoning effect of severa1 sulfur containing compounds on the hydrogenation of styrene and cyclohexene over Ni/Al2O3 catalyst was studied by a fixed-bed reactor. Results showed that at 70 oC and 1.0 MPa these sulfur containing compounds, such as CS2, CH3SSCH3, C4H4S, CH3(CH2)3SH and CH3SCH3, have negative effect on the activity of Ni/Al2O3 catalyst for hydrogenation of cyclohexene and phenyl of styrene. Under similar sulfur content, for the hydrogenation of phenyl of styrene the poisoning effects of sulfides from high to low were in the sequence of CH3SCH3≈CH3SSCH3＞C4H4S＞CS2＞CH3(CH2)3SH. For the hydrogenation of cyclohexene, the poisoning effects of sulfides on Ni/Al2O3 catalyst from high to low were in the order of CH3SSCH3＞CH3(CH2)3SH＞CS2＞CH3SCH3＞C4H4S. Carbon bisulfide was the main poison in the hydrogenation reaction of conjugated double bond of styrene and the negative effect increased with the increase of carbon bisulfide content; the negative effect decreased with the increase of reaction temperature.