Method and device for extracting and separating phenolic compounds from coal derived oil

Abstract

The invention discloses a method and device for extracting and separating phenolic compounds from coal derived oil. The method comprises the following steps of performing distillation and cutting to obtain phenol-enriched distillation fractions: performing distillation, distillation fraction and cutting on the coal derived oil, and cutting out a phenol-enriched distillation fraction of a certain temperature segment; performing centrifugation, extraction and separation on a solvent: performing centrifugation and separation on the phenol-enriched distillation fraction, an extraction agent and an addition agent so as to obtain a liquid phase containing an extraction agent, wherein a light phase of the liquid phase containing the extraction agent is a dephenolization oil-addition agent solution, a heavy phase of the liquid phase containing the extraction agent is an enriched phenolic compound, and the extraction agent is an aqueous solution of one or more selected from butanone, cyclohexanol, dihydric alcohol and glacial acetic acid; performing centrifugation, backward extraction and separation; recovering the addition agent; recovering reverse extraction agents; and refining crude phenols: performing azeotropic distillation and separation on crude phenol raw materials containing a few extraction agents so as to obtain the extraction agent and crude phenol products.

Description

technical field [0001] The invention relates to the technical field of separation of coal chemical and petrochemical products, in particular to a method and device for extracting and separating phenolic compounds from coal-derived oil. Background technique [0002] During the conversion process of coal, such as pyrolysis, coking, and gasification, a large amount of coal-derived oil rich in phenolic compounds will be produced, such as coking by-product high-temperature tar with a phenol content of 1-2.5% (mass fraction, the same below), and coal direct liquefied oil The content of phenol in medium and low temperature coal tar is as high as 15% to 30%. At present, the existing technology for separating and extracting phenolic compounds mainly adopts the acid-base elution method in industry, and uses the acidity of phenolic substances to neutralize them with aqueous sodium hydroxide solution. The resulting sodium phenolate is insoluble in the oil phase and transferred to water....

AI Technical Summary

Problems solved by technology

At present, the existing technology for separating and extracting phenolic compounds mainly adopts the acid-base elution method in industry, and uses the acidity of phenolic substances to neutralize them with aqueous sodium hydroxide solution. The resulting sodium phenolate is insoluble in the oil phase and transferred to water. phase, and then use carbon dioxide or sulfuric acid to reduce the sodium phenolate to phenolic substances. Practice shows that acid-base cleaning requires a large amount of strong acid and strong alkali aqueous solution, and there are the following problems: (1) a large amount of strong acid and strong alkali are easy to corrode process equipment , affecting the normal use of the equipment; (2) a large amount of strong acid and strong alkali aqueous solution will cause a large amount of phenol-containing wastewater to be produced during the separation process, which is likely to cause environmental pollution, and a large amount of K and Na ions in the wastewater are difficult to treat in the subsequent biochemical treatment; (3) acid The water content in the crude phenol product separated and extracted by the alkali elution method is relatively large (the relevant standard stipulates 10%), which increases the difficulty of follow-up treatment and processing costs; The extraction tower occupies a large area and consumes a lot of energy

In this process, the efficiency of multi-stage back extraction of phenol is low, and the entrainment of neutral oil is large, which affects the purity of phenols. Water vapor removes impurities such as neutral oil and consumes a lot of energy.

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