有机硫化物对Ni/Al_2O_3催化剂催化异戊二烯选择加氢的影响

Poisoning of Organic Sulfides to Ni/Al_2O_3 Catalyst Used in Isoprene Hydrogenation

在流体并流向上的气液固三相固定床反应器中考察了多种有机硫化物对Ni/Al2O3催化剂催化异戊二烯加氢活性的影响。实验结果表明,在低温(65℃)和液相加氢(压力1.0MPa)条件下,二甲基二硫醚和丁硫醇使Ni/Al2O3催化剂催化异戊二烯加氢活性显著下降;且随原料中硫含量的增加,异戊二烯加氢活性下降的程度增大。在硫含量相同(w(S)=90μg/g)的情况下,同系硫化物中,低碳数硫化物的毒性小于高碳数硫化物;同碳数硫化物使催化剂失活程度的大小顺序为:乙硫醇>二甲基二硫醚二甲基硫醚;相同烷基硫化物使催化剂失活程度的大小顺序为:二乙基二硫醚>乙硫醇二乙基硫醚,且二甲基硫醚、二乙基硫醚与噻吩的毒性相近,对Ni/Al2O3催化剂加氢活性的影响较小。

The poisoning of some organic sulfides to Ni/AlzO3 catalyst used in isoprene hydrogenation was studied in a fixed bed reactor with gas - liquid cocurrent up - flow. At 65℃ and 1.0 MPa, both dimethyl disulfide and 1 - butanethiol have negative effects on activity and stability of Ni/Al2O3 catalyst, and poisoning is processively serious with increase of sulfur content in the feed. Under the condition of same sulfur content （w（S） 90 μg/g）, and same type of organic sulfides, the poisoning effect is proportional to carbon number of organic sulfides. With different types of organic sulfide of two carbon atoms, ethanethiol is most poisonous, dimethyl disulfide is secondary and dimethyl sulfide the least. For organic sulfides with ethyl group, the poisoning effects on Ni/Al2O3 catalyst are in order of diethyl - disulfide 〉 ethanethiol〉〉diethyl - sulfide. Dimethyl sulfide, diethyl sulfide and thiophene are only lightly poisonous to the catalyst.