Ni/HZSM-5上裂解汽油选择加氢裂化的研究

在连续流动固定床装置上，探讨了非贵金属Ni/HZSM-5催化剂对裂解汽油选择加氢裂化反应的特征，考察了镍含量、温度、压力、空速及氢烃体积比等参数的影响。随镍含量的增加，裂解汽油中C6+非芳烃转化率先增加后减小，镍含量为2.1%左右较为适宜。工艺条件中温度和压力的影响较大，空速次之，氢烃体积比最小。在380 ℃、3.0 MPa、质量空速1.245 h-1、氢烃体积比1 000的条件下，以镍含量为2.1%的Ni/HZSM-5为催化剂，65 h内裂解汽油中C6+非芳烃组分转化率保持在95%以上，而芳烃转化率仅有13%; 加氢裂化产物中，C2+正构烷烃达80.96%，其中丙烷60.71%，而甲烷和异构烷烃较少。这表明非贵金属Ni/HZSM-5催化剂可高选择性地裂化C6+非芳烃，适用于裂解汽油加氢裂化制备芳烃联产低碳烷烃。

SELECTIVE HYDROCRACKING OF PYROLYSIS GASOLINE OVER Ni/HZSM-5 CATALYST

The selective hydrocracking of pyrolysis gasoline over non-noble metal catalyst Ni/HZSM-5 was studied in a fixed down-flow reactor, and the effects of nickel content and reaction parameters such as temperature, pressure, WHSV and H2/CH volume ratio were investigated. Test results showed that with the increase of nickel loading, the conversion of C6+ non-aromatics hydrocarbons in pyrolysis gasoline first increased and then decreased, the suitable nickel content of the catalyst was about 2.1%. Among the process conditions, temperature and pressure showed great influences, followed by WHSV and the effect of H2/CH ratio was the least. Using Ni2.1/HZSM-5 catalyst, under the conditions of 380℃, 3.0MPa, a WHSV of 1.245h-1 and a H2/CH volume ratio of 1 000, the conversion of C6+ non-aromatics hydrocarbons in pyrolysis gasoline kept more than 95% within 65 h, and the conversion of aromatics was only 13%. In the hydrocracking products, C2+ n-alkanes occupied 80.96%, in which propane occupied 60.71%. The results suggested that Ni/HZSM-5 catalyst having high selectivity for the hydrocracking of C6+ non-aromatics could be used for hydrocracking of pyrolysis gasoline to produce aromatics with light alkanes as co-products.