Method of hydrogenation recycling of waste mineral oil

Abstract

The application provides a method of hydrogenation recycling of waste mineral oil, which includes the following steps: (a) removing impurities from the waste mineral oil through pressurized settlement, filtration and centrifugal separation; (b) heating the waste mineral oil after the impurity removal and performing oil-water separation to remove water from the waste mineral oil; (c) performing pressure-reduced flash to the dehydrated mineral oil to remove light components and emulsified water; (d) in a multiple-effect tubular falling-film evaporator, performing heat exchange with a heat carrier under a pressure reducing condition, collecting a volatile component from the top to obtain pre-hydrogenated oil; (e) blending the pre-hydrogenated oil with the light components and performing a hydrogenation reaction to obtain a hydrogenation product; (f) feeding the hydrogenation product into a normal pressure distillation column for treatment, and collecting the top products, naphtha and white oil, from the normal pressure distillation column; (g) feeding the bottom product of the normal pressure distillation column into a pressure-reduced distillation column to perform pressure-reduced distillation for producing basic oil. The method has simple processes, is great in raw material adaptability, is not liable to cause coking, and is high in product quality.

Description

technical field [0001] The invention relates to the petroleum field, in particular to a method for recovering waste mineral oil through hydrogenation. Background technique [0002] The traditional method of recovering waste oil is to filter and settle the recovered waste oil to remove water and mechanical impurities, and then lighten it by thermal cracking to obtain black combustion diesel oil. It causes a lot of secondary pollution and destroys the relatively scarce lubricating oil components. [0003] Another method is to obtain lubricating oil base oil components through vacuum distillation of the waste lubricating oil that has been dehydrated and mechanical impurities, and obtain relatively inferior lubricating oil base oils through pickling, alkali neutralization, and clay refining. A large amount of acid slag, alkali slag and white clay slag will be produced during the production process, causing secondary pollution to the environment. Moreover, the lubricating oil c...

AI Technical Summary

Problems solved by technology

[0002] The traditional method of recovering waste oil is to filter and settle the recovered waste oil to remove water and mechanical impurities, and then lighten it by thermal cracking to obtain black combustion diesel oil. Causes a lot of secondary pollution and destroys relatively scarce lubricating oil components

[0003] Another method is to obtain lubricating oil base oil components through vacuum distillation of the waste lubricating oil that has been dehydrated and mechanical impurities, and obtain relatively inferior lubricating oil base oils through pickling, alkali neutralization, and clay refining. A large amount of acid slag, alkali slag and white clay slag will be produced in the production process, causing secondary pollution to the environment

Moreover, the lubricating oil component obtained after vacuum distillation is refined by solvent extraction process, and then passed through white clay, the appearance of the product obtained is yellow, and each index barely reaches the I-type base oil index, and white clay slag is produced to cause secondary pollution of the environment

In addition, both acid-base refining and solvent extraction can only improve the color of the oil, but hardly improve the viscosity index, saturated hydrocarbon content, pour point, sulfur content, and nitrogen content of the oil. Therefore, this type of method is less selective for raw materials. Strong, but because the sources of waste oil are relatively wide and the quality is relatively complicated, the quality of the products obtained by the traditional process is not stable

[0004] In recent years, hydrogenation technology has also been extended to the regeneration of waste oil, especially waste lubricating oil. However, due to certain problems in the pretreatment and distillation processes in the previous stage, severe coking has occurred, resulting in the inability of the hydrogenation unit to operate stably for a long period of time, and the need for continuous shutdown treatment, resulting in High cost and low product quality

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