Heavy dirty oil recovery method for oil refinery

Abstract

The invention relates to a processing method of water, waste water, sewage or sludge. A heavy dirty oil recovery method for an oil refinery disclosed herein comprises the following steps: (1) uniformly mixing salts containing multivalent metal ions with waste alkaline residues, then mixing with heavy dirty oil in proportion, and then standing until layering to obtain an upper layer, a middle layer, and a lower layer; (2) cutting off the lower layer, adding a certain amount of neutral water and acidic water to the rest two layers for mixing, standing the mixture and then layering to obtain an upper layer of oil phase and a lower layer of mud and water phase, cutting off the lower layer to obtain clear oil. According to the invention, by adopting two -step separation process to physically and chemically separate the heavy dirty oil recovered by a sewage treatment plant of the oil refinery, complete separation of oil, mud and water is realized, the recycled clear oil has low mud content and low water content and meets the recycle requirements. The method disclosed herein provides waste soda acid recycling and polluted oil recovery in petrochemical industry with a novel approach.

Description

technical field [0001] The invention relates to a treatment method for water, waste water, sewage or sludge. Background technique [0002] In the process of crude oil refining, a large amount of oily sewage will be generated in the process of crude oil electric desalting, water cutting in oil tank farms, equipment maintenance and laboratory sewage discharge. The sewage recovered after oil separation, flotation and coalescence is heavy sewage. Sludge oil is mainly composed of oil, sediment, organic sludge, surface active substances and a large amount of water. Heavy dirty oil generally exists in the form of W / O or O / W / O emulsion at room temperature, and it is difficult to break the emulsion. [0003] There are two main types of existing heavy oil separation technologies. One is to use an oil-water-solid three-phase centrifuge for separation. Western developed countries mostly adopt this technology. The advantage is that oil and mud can be completely separated; the disadvant...

AI Technical Summary

Problems solved by technology

Western developed countries mostly adopt this technology. The advantage is that oil and mud can be completely separated; the disadvantage is that the one-time investment is large, and the recovered oil still contains a large amount of emulsified water.

The second is to separate by heating and static sedimentation. The disadvantages are that the recovery period is long (generally more than 150 h of sedimentation is required), the steam consumption is large, and the recovered oil contains more water and flocculent organic sludge, which is not conducive to the recovery of the recovered oil. Refining