MDEA溶液对脱硫装置的腐蚀及其应对措施

Corrosion of Desulfurization Unit by MDEA Solution and its Countermeasures

针对中海石油舟山石化有限公司脱硫装置中N-甲基二乙醇胺(MDEA)系统所遇到的设备腐蚀泄漏问题,进行了深入的原因分析,并提出了有效的应对措施。研究表明,尽管胺液本身不具腐蚀性,但其吸收的H_2S及降解产物热稳定盐对碳钢设备具有显著腐蚀作用。通过对换热器、空冷器、管线和阀门等关键设备的腐蚀情况的调查,揭示了腐蚀的主要原因包括热稳定盐腐蚀、冲刷腐蚀、应力腐蚀以及设备结构设计不合理等。提出了包括材质升级、胺液净化、应力热处理、操作调整和工艺管理优化等一系列改进措施,以减缓腐蚀速率并提高设备使用寿命。实施后,显著降低了腐蚀速率,确保了装置的稳定运行。

In this paper,the corrosion and leakage of N-methyldiethanolamine(MDEA)system in the desulphurization unit of CNOOC Zhoushan Petrochemical Co.,Ltd.was analyzed,and the effective countermeasures were put forward.The results show that although the ammonium solution itself is not corrosive,the H2S absorbed by it and the thermal stable salt of the degradation product have a significant corrosive effect on carbon steel equipment.Through the investigation of corrosion of key equipment such as heat exchangers,air coolers,pipelines and valves,it is revealed that the main causes of corrosion include heat stabilized salt corrosion,erosion corrosion,stress corrosion and unreasonable equipment structure design.A series of improvement measures including material upgrading,amine purification,stress heat treatment,operation adjustment and process management optimization are proposed to slow down the corrosion rate and increase the service life of the equipment.After implementation,the corrosion rate is significantly reduced and the stable operation of the device is ensured.