裂解汽油一段加氢用Ni/Al_2O_3催化剂CS_2中毒研究

Poisoning of Ni/Al_2O_3 catalyst for first-stage hydrogenation of pyrolysis gasoline by carbon disulfide

采用固定床反应器研究了Ni/Al2O3上CS2对裂解汽油原料油中主要化合物芳烃、单烯烃和共轭烯烃加氢活性的影响,其对加氢抑制的顺序为:芳烃>单烯烃>共轭烯烃。XRD、XPS和IR表征分析表明,Ni/Al2O3催化剂失活的可能原因是CS2吸附在活性相表面,部分CS2碳硫键断裂发生氢解反应产生H2S和CH4,H2S与镍活性中心作用形成镍硫化合物。原料油中部分CS2吸附在催化剂表面,催化剂对共轭烯烃加氢也失去活性。

Influence of the poisoning of Ni/Al2O3 catalyst for hydrogenation of model pyrolysis carbon disulfide（ CS2 ） on hydrogenation of aromatics, monoene and conjugated alkenes was gasoline by investigated in a fixed-bed reactor. The results indicated that carbon disulfide has negative effect on catalytic activity of Ni/Al2O3 for hydrogenation of aromatic nucleus, monoene and conjugated alkenes in the sequence of aromatic nucleus 〉 monoene 〉 conjugated alkene. XRD XPS and IR results indicated that first carbon disulfide was adsorbed on surface of the nickel catalyst, followed by cleavage of C=S bond of some carbon disulfide via hydrogenolysis, producing H2S and CH4. H2S reacted with nickel atoms to form nickel sulfide species, causing poisoning of the active metal. Carbon disulfide was adsorbed on surface of nickel catalyst and resulted in loss of activity for hydrogenation of conjugated double bonds.