Dephenolization method of phenol-containing oil

Abstract

The invention belongs to the technical field of coal tar processing, and discloses a dephenolization method of phenol-containing oil. According to the method, a water solution of a small-molecule alcohol is selected as a solvent, so that a good selective dissolving capability on lower phenol is achieved. After the phenol-containing oil is subjected to solvent extraction, a solvent in raffinate-phase crude dephenolization oil can be separated and recovered through a distillation or gas stripping method and can be recycled and reused. The method is low in extraction solvent loss, high in phenolyield and low in operation cost, is free of pollutant emission, and is suitable for separation of phenolic compounds in phenol oil distillate of high-temperature coal tar and in phenol-containing oilfractions in medium-low-temperature coal tar. Particularly, the recovery rates of lower phenols such as phenol, cresol and the like can reach 85% or above.

Description

technical field [0001] The invention belongs to the technical field of coal tar processing, and in particular relates to a method for dephenolizing oil containing phenol. Background technique [0002] Coal tar contains a variety of chemicals, and has been developed and utilized by domestic and foreign enterprises as a resource of special chemicals for a long time. Low-level phenol is one of the important products separated from coal tar. Since the molecule of phenol is weakly acidic, the acid-base method (using sodium hydroxide solution to react with phenol to form sodium phenolate, which is then reduced by a stronger acid) into phenols, and finally separate phenolic compounds from coal tar phenolic distillate oil) it is easy to separate low-grade phenol products from coal tar. This method has the advantages of high phenol yield, simple process, and low operating cost, and has been used all the time. It is used in industrial production, but its disadvantage is that acid res...

AI Technical Summary

Problems solved by technology

Although the non-acid-base separation of phenol technology solves the problem of pollutant discharge, there are still some shortcomings in different technologies

Among them, the solvents used in the solvent extraction method include glycerol, diethanolamine, aqueous solutions of small molecule organic amines, and aqueous ammonia, and aqueous solutions of some inorganic salts. However, some technologies have problems such as low yield of phenolic compounds and low extraction efficiency, and some technologies have problems such as large solvent loss and high production costs; ionic liquid extraction technology can obtain relatively high selectivity of phenolic compounds, but due to the high cost of ionic liquids , its regeneration cost and consumption may cause high production cost of this type of technology, thus affecting its economy; superheated steam extraction technology needs to be operated at a higher temperature, on the one hand, the energy consumption is high, on the other hand, due to the use of Oil and gas are mixed in the water vapor, which makes it difficult for the water vapor to be recycled.

Images