基于中压加氢改质方案的炼油流程协同优化

中国石化北京燕山分公司(简称燕山分公司）为增产高附加值产品、提升效益，对炼油系统进行了流程协同优化。中压加氢裂化装置掺炼催化裂化柴油，由加氢裂化方案改为加氢改质方案运行，将改质柴油送入三号催化裂化装置（简称三催化装置）的提升管进行回炼；同时，将焦化蜡油改入加氢裂化装置进行加工，而蜡油加氢装置不再加工焦化蜡油以改善催化裂化原料。协同优化后，中压加氢改质装置的柴油产品十六烷值提高7个单位；三催化装置的液化气收率提高1.96百分点，汽油收率增加0.88百分点，总液体收率增加2.28百分点；高压加氢裂化装置喷气燃料产品的密度（20 ℃）降低至806 kg/m3，烟点为23.8 mm，尾油BMCI由11.8降低至10.8；蜡油加氢装置精制蜡油的饱和分质量分数提高4.68百分点，芳香分质量分数降低5.96百分点，氮质量分数降低0.06百分点，使催化裂化原料性质得以改善。通过将中压加氢改质装置的喷气燃料馏分抽出送催化裂化装置回炼，与回炼改质柴油相比，催化裂化汽油的研究法辛烷值（RON）增加1.0个单位，改质柴油十六烷值提高4.8个单位。通过全炼油板块系统性优化，燕山分公司车用柴油产品的十六烷值由53.5降低至51.5，解决了质量过剩问题。

COLLABORATIVE OPTIMIZATION OF REFINING PROCESS BASED ON MEDIUM PRESSURE HYDRO-UPGRADING SCHEME

To increase the production of high value-added products and improve the benefits,SINOPEC Beijing Yanshan Company made collaborative optimization for the oil refining sector. The medium-pressure hydrocracking unit used a mixed feed blending with FCC diesel fraction, and ran in hydroupgrading scheme instead of hydrocracking, the upgraded diesel was returned to No.3 FCC unit for refining. At the same time, to improve the catalytic cracking feed properties, the CGO was fed into hydrocracking unit and no longer processed in the hydrotreating unit. After collaborative optimization, the cetane number of the medium-pressure hydrocracking diesel was increased by 7 units. The LPG yield of No.3 FCC was increased by about 1.96 percentage points, the gasoline yield was increased by 0.88 percentage points, and the total liquid was increased by 2.28 percentage points. The jet fuel density ( 20℃) of hydrocracking unit was reduced to 806 kg/m3 with a smoke point of 23.8 mm, and the BMCI of tail oil was reduced from 11.8 to 10.8. The saturated hydrocarbons of hydrotreated VGO were increased by 4.68 percentage points with a reduction of 5.96 percentage points of aromatics and 0.06 percentage points of nitrogen content, respectively, resulting in improved FCC feed quality. The jet fuel distillate of the medium pressure hydroupgrading unit was cycled back to FCC unit. Compared with the process of recycling back the upgraded diesel oil, the research octane number (RON) of the catalytic cracking gasoline was increased by 1.0 unit and the cetane number of the upgraded diesel oil was increased by 4.8 units. Through collaborative optimization of the whole refining scheme, the cetane number of vehicle diesel product of Yanshan petrochemical branch was reduced from 53.5 to 51.5, which solved the problem of excess quality.