3.75 Mt/a柴油液相加氢精制装置运行问题及对策

Operating problems in the 3.75 MM TPY diesel liquid-phase hydrorefining unit and countermeasures

某石化公司3.75 Mt/a柴油加氢装置的工艺设计采用Iso Therming液相加氢处理技术,设置一台液相加氢反应器,生产满足欧Ⅳ排放标准的清洁柴油。2016年1月,装置进行升级改造,在原液相加氢反应器下游增加一台液相反应器及相应的配套设施,生产欧Ⅴ排放标准的清洁柴油。装置运行期间,经常发生原料过滤器反冲洗频繁和汽提塔回流罐酸性气管线堵塞的现象,反冲洗频繁严重时造成过滤器PLC程序自保停止工作,使上游装置憋压,影响装置的长周期和稳定运行。通过分析得知,焦化柴油携带焦粉是造成柴油原料过滤器反冲洗频繁的主要原因,硫化氢铵盐是导致汽提塔回流罐酸性气管线堵塞的主要原因。采取相应的处理措施后,影响运行的问题得到解决。

Iso Therming liquid-phase hydrogenation process was applied for a 3.75 MM TPY diesel hydrogenation unit of a petrochemical company.In this process,a liquid-phase hydrogenation reactor was installed to produce clean diesel which met Euro Ⅳ standard specifications.In January,2016,the unit was upgraded by revamping in which a liquid-phase hydrogenation reactor was added downstream of the original liquid-phase hydrogenation reactor and associated auxiliary facilities were installed to produce Euro Ⅴ clean diesel.In the operation of the unit,the feed filters had to be frequently back flushed and sour gas pipeline of reflux tank of the stripper was frequently blocked.When frequent back flushing was required,the filter＇s PLC program stopped working,which resulted in upstream pressure build-up and affected the long-term stable operation of the unit.It was known from analysis that the main cause of frequent back flushing was due to the coke powder carry-over in coker diesel,while the hydrogen sulfide ammonium is the culprit for the plugging of the acid gas pipeline of stripper reflux tank.Countermeasures were finally recommended and associated problems were effectively solved.