MDEA再生塔塔底重沸器管束腐蚀分析与对策

采用金相显微镜、XRD、SEM和EDS等观察分析手段对脱硫再生塔塔底重沸器管束的腐蚀原因进行了分析。结果表明:重沸器管束穿孔部位表面呈现大量蜂窝状腐蚀坑形貌,存在大量S、Cl等腐蚀元素,腐蚀产物主要为FeS₂、FeS的混合物。腐蚀失效主要是由于原料中的H₂S、CO₂以及Cl-等酸性介质构成RNH₂-H₂S-Cl-热稳定性盐及H₂O体系的腐蚀和气泡腐蚀所致。并针对失效原因,提出了改进措施和建议。

Failure Analysis and Measures of Corrosion of Reboiler Tubes of MDEA Regeneration Tower

The corrosion failure cause of reboiler tubes of a desulfurization regeneration tower in a refinery was investigated by microscopy, XRD, SEM and EDS. The results show that there existed a number of cellular corrosion pits at the surface of puncture site of the reboiler tubes, consisting of a lot of S, Cl and other corrosion elements. The corrosion products were mainly composed of FeS₂ and FeS. The corrosion failure of the reboiler tubes was mainly caused by corrosion of the RNH₂-H₂S-Cl--Thermal stable salts-H₂O system made up of the acidic materials of H₂S, CO₂ and Cl- in raw material, and bubble corrosion. Finally, some measures and suggestions were put forward according to the failure cause.