常减压蒸馏装置工艺防腐对策

Process corrosion protection for atmospheric-vacuum distillation unit

中国石油化工股份有限公司九江分公司Ⅰ套常减压装置在2011年9月装置大检修期间,检查发现常压塔塔顶塔盘、回流管、挥发线和减压塔填料等腐蚀较为严重。通过分析腐蚀机理,确定了其主要腐蚀类型为低温HCl-H2S-H2O腐蚀和高温硫腐蚀、环烷酸腐蚀,并提出针对性措施:优化电脱盐操作,降低脱后盐含量;根据装置现场情况,优化防腐剂的注入点和注入流程;实施探针在线监测系统,实时监控和掌握装置易腐蚀部位的腐蚀速率。通过以上几个措施,有效减缓装置腐蚀程度,延长装置运行周期。

In the turnaround of 1 # atmospheric -vacuum distillation of SINOPEC Jiujiang Petrochemical Company in september, 2011, serious corrosion was found in tower overhead trays, reflux pipe, vapor line and packings in vacuum tower, etc. The analysis of corrosion mechanims concluded that the corrosions were mainly the low - temperature HC1-H2 S-H2 0 corrosion, high - temperature sulfur corrosion and napthenie acid corrosion. The following countermeasures were proposed： I. strengthening the management of electric desaher and optimizing its operation to reduce the salt in the desalted crude oil; 2. optimizing injection point and injection process of corrosion inhibitor based upon specific unit conditions; implementing on - line probe detection system to monitor in real time the locations of the equipment which is subject to corrosion and corrosion rate of pipelines. The implementation of above measures has effectively mitigated the corrosion and extended the operation cycle of the unit.