催化剂级配技术在300万t/a柴油加氢裂化增产化工原料装置中的应用

Application of catalyst gradation technology in 3 million t/a diesel hydrocracking unit for increasing yield of chemical feedstocks

为了提高产品质量、降低柴汽比、增产化工原料,将350万t/a柴油加氢精制装置改造为300万t/a柴油加氢裂化装置,采用A公司HDS催化剂体相催化剂及加氢裂化催化剂级配来实现柴油加氢超深度脱硫时增产化工原料,装置改造中反应系统改动较少,主要集中在分馏部分。标定数据表明,加工直馏柴油工况,反应压力7. 35 MPa,催化剂床层平均温度为340. 2℃,重石脑油硫含量0. 1μg/g,氮含量0. 3μg/g,重石脑油收率达到17. 82%,喷气燃料冰点为-55. 9℃,烟点为28. 5 mm,精制柴油硫含量5. 5μg/g,多环芳烃0. 8%,达到国Ⅵ柴油标准。在多掺炼20%催化柴油工况,床层平均温度提高11℃,重石脑油收率达到12. 98%,重石脑油质量可满足重整料要求,精制柴油达到国Ⅵ柴油标准。

In order to improve the quality of products,reduce the yield ratio of diesel to gasoline and increase the production of chemical feedstock,a 3. 5 million t/a diesel hydrorefining unit is renovated into a 3. 0 million t/a diesel hydrocracking unit. The target to increase the yield of chemical feedstocks in ultra-deep desulfurization of diesel hydrogenation is achieved through gradation between bulk hydrorefining catalyst and the hydrocracking catalyst.There are few changes for the reaction system in the renovation,which focuses mainly on the fractionation section. The industrial calibration results show that as it is processing straight distillation diesel fuel,the reaction pressure remains at7. 35 MPa,the temperature of the catalyst bed is averaged at 340. 2℃,the sulfur and nitrogen contents in heavy naphtha are 0. 1 μg·g-1 and 0. 3 μg·g-1,respectively,the yield of heavy naphtha reaches 17. 82%,jet fuel has a freezing point of-55. 9℃ and a smoke point of 28. 5 mm. The refined diesel oil contains 5. 5μg·g-1 of sulfur and 0. 8% of polycyclic aromatic hydrocarbon,which meets China’s national standard Ⅵ for diesel.Although 20% of catalytic diesel is blended,the temperature of the catalyst bed is averaged at 11℃,and the yield of heavy naphtha reaches 12. 98%.The quality of heavy naphtha can meet the requirements of reforming feedstock,and the refined diesel can meet China’s national standard Ⅵ.