蜡油加氢装置硫化氢汽提塔的腐蚀与防护

Corrosion and Protection for Hydrogen Sulfide Stripping Tower 9in Wax Oil Hydrogenation Unit

介绍了中国石油化工股份有限公司天津分公司炼油部蜡油加氢装置中硫化氢汽提塔的工艺流程及腐蚀概况,在2012年大修过程中发现该塔存在较为严重的腐蚀问题,第2和第3人孔附近筒体内衬及短接内衬出现腐蚀麻坑;由上而下第7～9层塔盘腐蚀严重,局部腐蚀穿透、浮阀脱落;第2人孔段低分油进料分配管表面有大量腐蚀麻坑与沟槽。针对相关腐蚀情况分析了腐蚀原因,主要由于硫化氢汽提塔的塔顶存在H2S-HCl-H2O的腐蚀体系,并且存在点蚀和冲刷腐蚀。从工艺、改善腐蚀环境、选材及使用方面提出了相应的防护措施。

The process conditions of the hydrogen sulfide stripping tower in wax oil hydrogenation unit of SINOPEC Tianjin Company are introduced. In 2012 serious corrosion problems were found in the process of overhaul maintenance. Pockmark corrosions of cylinder lining and short connected liner were found in the area near 2nd and 3rd manholes. And there were serious corrosions in the 7th , 8th and 9th layers of trays such as penetrating corrosion and float valve falling off. Serious corrosion problems also appeared in the oil feed distributing tube near the 2nd manhole. The causes of corrosion were analyzed and found to be the HaS- HCl - H2O corrosion system in the overhead of the hydrogen sulfide stripping tower, pitting corrosion and erosion corrosion. The corresponding corrosion protection measures were recommended in respect of process, improvement of operating conditions and material selection, etc.