加工低硫高酸值原油防腐蚀成套技术

国内胜利、辽河、克拉玛依三大老油田均有相当数量的低硫高酸值原油,这种原油在电脱盐过程中易造成乳化并产生大量污油。选用SH9101、FC9301等高效广谱破乳剂并采用具有鼠笼式电极板结构的新型电脱盐罐,可达到脱后盐含量小于3mg/L的指标。采用溶剂萃取的方法（注碱和增溶剂）对高酸值的辽河蜡油进行脱除环烷酸试验,脱除率可达90％以上。在电脱盐过程中,加入某些药剂,原油脱酸率也可达到60％左右。采用高温缓蚀剂可有效抑制环烷酸的腐蚀,使碳钢设备的腐蚀率降至0.4mm/a以下,高温缓蚀剂将成为炼制低硫高酸原油的主要防腐蚀措施。此外,渗铝钢将成为替代不锈钢的廉价耐环烷酸腐蚀材料。

Package Corrosion Protection Technologies for Processing Low-sulfur High-acid Value Crudes

Three domestic oil fields like Shengli, Liaohe and Kelamayi produce large amount of low-sulfur high-acid value crude oils. These oils will easily emulsify and produce a large amount of waste oil when it is processed in the crude desalter. The salt content in the desalted oil can be reduced to less than 3mg/L if the high-efficiency wide-spectrum demulsifiers such as SH9101, FC9301 etc are selected and the new desalter drum with squirrel-cage electric plate are applied. The tests to remove naphthenic acid from high-acid value gas oil using solvent extraction process (injection of caustic and solubility improver) indicated that 90% of naphthenic acid could be removed. In electrostatic desalting, the acid removal rate could be as high as about 60% if some chemicals were applied. The application of high-temperature corrosion inhibitor, which would become the major corrosion prevention measure for processing low-sulfur and high-acid value crudes, could effectively control the naphthenic acid corrosion and reduce the corrosion rate of carbon steel to less than 0.4 mm/yr. Besides, the aluminum diffused steel would become one of the cheap naphthenic acid resistant materials to replace stainless steel.