焦化汽油加氢装置预保护反应器精制油终馏点升高原因分析

Analysis of the reasons for the increase in final boiling point of refined oilin the pre-protection reactor of coking gasoline hydrogenation unit

针对某焦化汽油加氢装置预保护反应器运行初期精制油终馏点大幅度升高的问题,对两周期使用的加氢催化剂进行对比分析,并开展了中试试验研究。通过分析油品性质、烃类组成以及硫化物结构变化,初步掌握了精制油终馏点升高的原因。中试试验结果表明,预保护反应器精制油终馏点升高值可达22℃,终馏点升高属于正常现象。相比于原料,精制油蒸馏残余物中单环芳烃和双环芳烃含量增幅均在2.0百分点以上,精制油中苯并噻吩含量增加2倍以上。多环芳烃和大分子含硫化合物的生成是精制油终馏点升高的原因。较低的加工负荷更容易导致高沸点重组分的生成,因此,焦化汽油加氢装置预保护反应器的加工负荷不宜过低。

In response to the problem of a significant increase in the final boiling point of refined oil during the initial operation of the pre-protection reactor in a coking gasoline hydrogenation unit of a certain enterprise,a comparative analysis was conducted on hydrogenation catalysts used in two cycles,and pilot tests were carried out.By analyzing the properties of oil products,hydrocarbon composition,and changes in sulfide structure,the reasons for the increase in the final boiling point of refined oil have been preliminarily understood.The pilot test results indicate that the final boiling point of refined oil in the pre-protected reactor can increase by up to 22℃,which is a normal phenomenon.Compared to the feedstock,the content of monocyclic aromatic hydrocarbons and bicyclic aromatic hydrocarbons in the distillation residue of refined oil increased by more than 2.0 percentage points,and the content of benzothiophene in refined oil increased by more than twice.The generation of polycyclic aromatic hydrocarbons and large molecule sulfur-containing compounds are both reasons for the increase in the final boiling point of refined oil.When operating under lower load conditions,it is more likely to lead to the generation of high boiling point heavy components.Therefore,the processing load of the pre-protection reactor in the coking gasoline hydrogenation unit should not be too low.