Abstract:

The cleaning of crude oil tank mainly adopts the method of mechanical cleaning. A refinery has a total of 12 crude oil tanks, and the tank cleaning waste oil by mechanical cleaning is about 6,000 TPY. The iron mass fraction of the waste oil is as high as 5,692 μg/g, with high impurity content and unstable properties, making it difficult to directly utilize. The refinery uses SOTU(slop oil treatment unit) waste oil treatment technology to purify the tank cleaning waste oil, effectively separating oil, water, and solid residues from the waste oil. After separation, the water mass fraction of the purified oil is 1.6%, and the iron mass fraction is 359.8 μg/g, which meets the requirements of the downstream unit for recycling; the oil mass concentration of sewage is 100.88 mg/L, which can be directly sent to the sewage treatment unit; the water mass fraction of solid residues is 25.7%, which can be entrusted to hazardous waste recovery department. Using SOTU technology to purify the tank cleaning waste oil can effectively improve its the utilization value and further realize the reduction of hazardous waste. The recovery benefit of one ton waste oil can be 3,550 yuan, which has good economic benefits and application prospects.

Key words: refinery tank cleaning waste oil, mechanical cleaning, pretreatment, horizontal screw centrifuge, light phase centrifuge, heavy phase centrifuge, benefit analysis

摘要：

原油储罐的清洗主要采用机械清洗的方式。某炼油厂共有原油储罐12座，因机械清洗产生的清罐污油约6.0 kt/a。清罐污油的铁质量分数高达5 692μg/g,杂质含量高，性质不稳定，难以直接利用。该炼油厂利用SOTU污油处理技术对清罐污油进行净化处理，对污油中的油、水、固体残渣进行有效分离。分离后，净化油的水质量分数为1.6%、铁质量分数为359.8μg/g,满足下游装置的回炼要求；污水的油质量浓度为100.88 mg/L,可直接送至污水处理装置进行处理；固体残渣的水质量分数为25.7%,可委托危险废物回收单位处理。利用SOTU污油处理技术对清罐污油进行净化处理，能够有效提高清罐污油的利用价值，进一步实现危险废物减量化；处理每吨污油可回收效益3 550元，具有较好的经济效益及应用前景。

关键词: 炼油厂清罐污油, 机械清洗, 预处理, 卧式螺旋离心机, 轻相离心机, 重相离心机, 效益分析