催化裂化汽油加氢后博士试验不合格原因分析及应对

Reason analysis and countermeasures for disqualification of doctor test after catalytic cracking gasoline hydrogenation

中国石化青岛石油化工有限责任公司(青岛石化)汽油选择性加氢脱硫(RSDS)装置加氢原料汽油中烯烃含量较上周期增加,催化裂化稳定汽油在加氢脱硫的同时,产生了二次大分子硫醇,影响了博士试验通过率。优化操作使混合汽油总硫低于8μg/g后仍会发生博士试验不通过的情况,对于青岛石化汽油产品的顺利出厂产生了较大影响。因此,青岛石化以化验分析数据为基础,分析发现博士试验不通过的主要是原料烯烃含量、硫含量的增加以及催化剂烯烃饱和活性的下降导致大分子硫醇产生造成的。总结提出通过调整轻重汽油切割比例、使用低硫组分调合和采用串联氧化脱臭单元解决博士试验通过率低的问题。目前RSDS装置混合汽油中硫醇硫质量分数低于1μg/g,混合汽油博士试验全部通过。

The olefin content in the hydrogenation feedstock gasoline of SINOPEC Qingdao Petrochemical Co.,Ltd.(Qingdao Petrochemical)RSDS unit has increased compared to the previous cycle.During the hydrodesulfurization of catalytic cracking stabilized gasoline,secondary macromolecular mercaptans are produced,which affects the pass rate of doctor test.After optimizing the operation to ensure that the total sulfur of the mixed gasoline is less than 8μg/g,there may still be cases where the doctor test fails,which has a significant impact on the smooth delivery of gasoline products from Qingdao Petrochemical.Therefore,based on the laboratory analysis data,Qingdao Petrochemical find that the main reasons for the failure of the doctor test are the increase of olefin content and sulfur content in feedstocks and the production of macromolecular mercaptan by the decrease of olefin saturation activity of the catalyst.This paper summarizes and proposes methods such as using low sulfur components for blending,adjusting the cutting ratio of light and heavy gasoline,and using series oxidation deodorization units to solve the problem of low pass rate of the doctor test.At present,the mercaptan sulfur content in mixed gasoline of RSDS unit is less than 1μg/g,the doctor tests of mixed gasoline have all passed,and the running effect is good.