炼制进口原油常减压装置的腐蚀问题

Corrosion of Atmospheric-vacuum Distillation Unit Processing Imported Crudes

胜利炼油厂第三常减压装置改炼进口高硫原油或进口原油掺炼陆上原油后 ,设备腐蚀明显加重 ,致使换热器E2 4/ 1和空冷器A1/ 1腐蚀率高达 2 .5mm/a。腐蚀加重的主要原因是由于原油脱后盐含量偏高 ( 10～ 2 0mg/L)、硫含量高 ( 1.5 %～ 2 .5 % )所造成的塔顶及其冷凝冷却系统H2 S -HCl-H2 O环境的腐蚀 ,高温重油部位则主要是环烷酸引起的腐蚀。同时提出了改造电脱盐系统。

The corrosion began to deteriorate in the equipment of 3# atmospheric-vacuum distillation unit in Shengli Refinery when high-sulfur imported crudes or onshore crude blended with the imported crudes were processed. The corrosion rate of the heat exchanger E24/1 and air cooler A1/1 was as high as 2.5 mm/yr. The analysis indicated that the corrosion was mainly the H 2S-HCl-H 2O corrosion of the overhead and condensing system caused by higher salt content in the desalted crude (10~20 mg/L) and higher sulfur (1.5%～2.5%). The culprit of the corrosion in high-temperature heavy oil section was naphthenic acid. The protection measures such as revamping of the crude desalting system and optimization of the crude blending and chemical dosage were presented.