催化裂化轻循环油加工路线对柴汽比的影响

摘要

以某规划新建炼油厂研究方案为例,提出催化裂化轻循环油(LCO)总加工流程优化的新思路,根据LCO不同馏分段的组成特点及硫化物脱硫难易程度分馏为:LLCO(小于260 ℃轻馏分)、MLCO(260~340 ℃馏分)及HLCO(大于340 ℃馏分).其中,LLCO进柴油加氢精制装置,而富含多环芳烃的MLCO和HLCO则分别进加氢裂化装置和渣油加氢装置,增产重整料和催化裂化原料,因此在柴油产品产量降低的同时间接地增加汽油和芳烃产品的产量.结果表明,与基础方案相比,优化方案的汽油产量增加415.6 kt/a,对二甲苯和苯分别增加33.3 kt/a和14.7 kt/a,柴油产量减少774.0 kt/a,全厂柴汽比由1.38降至1.04,降柴汽比效果显著.%Some new ideas for optimal use of LCO for a grassroots refinery were proposed.According to the composition features as well as the complexity of desulfurization of different fractions,LCO is divided into three narrow fractions,ie.LLCO(light fraction of LCO,< 260 ℃),MLCO(middle fraction of LCO,260-340 ℃)and HLCO(heavy fraction of LCO,>340 ℃).LLCO is pumped to low pressure diesel hydrotreating unit,while MLCO and HLCO,rich in PAHs(polycyclic aromatic hydrocarbons),are processed in hydrocracking unit and residue hydrodesulfurization unit,respectively,to produce reforming and FCC feed.Therefore,the yield of gasoline and aromatic product increases while diesel production decreases.The results show that for optimized scheme,the production of gasoline,PX and benzene increases by 415.6 kt/a,33.3 kt/a and 14.7 kt/a,respectively,while that of diesel decreases by 774.0 kt/a,and the diesel/gasoline ratio reduces from 1.38 to 1.04.Meanwhile,the refining margins rise by 6.93 Yuan per ton crude,bringing remarkable economic benefit.