乙烯装置碱洗及废碱氧化系统存在问题及处理措施

PROBLEMS IN OPERATION OF CAUSTIC TOWER AND WASTE CAUSTIC OXIDATION SYSTEM OF ETHYLENE PLANT AND THE TREATMENT

介绍了中沙(天津)石化乙烯装置碱洗及废碱氧化系统。分析了装置前期运行时出现的废碱氧化系统反应器压力波动、废碱外送管线泄漏等问题,确定了碱洗塔碱浓度梯度小、废碱预处理系统聚结器失效、废碱储罐撇油泵故障、废碱外送配酸时导致物料p H值低等是造成问题的主要原因。通过采取碱洗塔补水线优化改造、更换废碱预处理系统聚结器填料、更换废碱储罐撇油泵型式、增加废碱配酸返回线等技改措施后,碱洗及废碱氧化系统目前运行平稳,运行参数接近设计值,运行各项指标满足生产要求。

This article introduces the caustic tower and waste caustic oxidation system in the ethylene plant at SINOPEC SABIC Tianjin Petrochemical Co.,Ltd.,analyzes the problems including the reactor pressure fluctuations in waste caustic oxidation system and the leakage of waste caustic pipeline,and identifies that the main reasons for the problems include the small caustic concentration gradient in caustic tower,the failure of coalescer in waste caustic pretreatment system,the failure of oil skimmer pump in waste caustic storage tank and the low pH value of wastewater when adding acid to the waste caustic. After taking some measures such as optimizing the make-up water pipeline in caustic tower,replacing the packing in the coalescer of waste caustic pretreatment system,changing the type of oil skimmer pump in waste caustic storage tank and installing acid adding return pipeline,the stable operation of the caustic tower and waste caustic oxidation system can be achieved,the operation parameters are close to the design value,and all the operation indicators meet the production requirements.