Pt/SAPO-11催化剂上柴油馏分临氢异构化改质反应研究

Study on Hydroisomerization of Diesel Fuel over Pt/SAPO-11

以SAPO-11为载体制备了Pt/SAPO-11柴油异构降凝催化剂.采用微反评价选取n-C12烷烃为柴油模型分子进行临氢异构化反应研究,结果显示异构化产物以单甲基异构体为主,在多支链的异构体中以双甲基异构体为主.同时,采用固定床加氢装置考察了催化剂对不同性质柴油原料的异构化性能.实验结果表明,处理直馏柴油和焦化柴油时,在实现柴油深度降凝的同时柴油收率达到95%以上,且十六烷值有所提高,生产的-20#、-35#清洁柴油性能可达到国家优质低凝柴油指标,该催化剂具有较高的实际应用潜力.

Pt/SAPO-11 catalyst was designed and prepared used for hydroisomerization of the distillated diesels to decrease the freezing point. Single long n-C12 and different diesels were hydroisomerized at 300～385℃ in a fixed-bed reactor. The product distribution of n-C12 isomers and hydroisomerization of on the catalyst was extensively analyzed. Results indicated that the n-C12 alkane undergo almost exclusively a single methyl and double methyl branching. There is a minimum in the distribution at the highly branched isomer. This peculiar product distribution can be explained by the different pore-mouth and key-lock modes of physisorption of alkanes in the pore openings of the SAPO-11 zeolites. It means that Pt/SAPO-11 might be potentially commercial catalyst with high performance of hydroisomerization of the distillated diesels.