Hydrocracking Catalyst Development In Flexible Production Of Middle Distillate Oil And Tail Oil

Hydrocracking, which is characterized by strong adaptability to raw materials, high liquid product yield, flexible product solutions and good product quality. As the only direct clean fuel production technology of light-end products of heavy oil, hydrocracking can directly produce clean China V diesel in which sulfur content is less than 10 ug/g, 3# jet fuel, and can produce-35# low freezing diesel in a large scale in winter. Heavy naphtha is excellent catalytic reformer feed, hydrocracking tail oil can be used as the feed of ethylene steam cracking as well as raw material of API Ⅱ, Ⅲ lube base oil.Modified Y zeolite and Beta zeolite were studied as hydrocracking catalyst carrier in this thesis. A hydrocracking catalyst in flexible production of middle distillate oil and tail oil was prepared by impregnation method using optimized modified Y zeolite and Beta zeolite as acid component, Ni-W as active component, and VA group element as additives, and the preparation conditions were optimized. Catalyst properties were characterized by analysis techniques such as XRD, BET. The operating conditions, stability and regeneration performance were evaluated on a hydrogenation test unit using daqing mixing gas oil, and the pilot of catalyst was examined. Getting the following results:(1) The hydrocracking catalyst which using amorphous silicon aluminum and modified Y+Beta zeolite as acidic components, metal W-Ni as hydrogenation components has good activity.(2)The excellent reaction conditions were: hydrogen partial pressure 14.4MPa, volumetric space velocity1.5h-1, hydrogen to oil 1300:1, and the temperature and the conversion is linear relationship in the investigation range.(3) The test results for the catalyst showed that the reaction temperature 379℃, C5+ liquid yield of 98.5wt%, middle distillates yield of 80.2 wt% were obtained under controlling conversion of >370℃ distillate at 65%. Meanwhile,the diesel yield was 52.36 wt%, with freezing point of-12℃, the tail oil yield was 34.74 wt %, with BMCI value of 7.2.(4) 3000 h test showed that catalyst has good activity stability with heating rate was 0.010℃/d, can meet the needs of operation for a long time. The evaluation results of the regenerated catalyst reached the level of the fresh catalyst, the catalyst has good regenerative properties;(5) 20 kg pilot of catalyst show that the catalyst has stable quality, the physical and chemical properties repeated the lab results.