Method for extracting biphenyl and indole from recycling washing oil of coal oil

A technology for coal tar and oil washing, which is applied in the field of purification of biphenyl and indole, can solve problems such as not seen, and achieve the effects of low production cost, high product yield, and improved reuse value.

Active Publication Date: 2008-08-20
BAOWU CHARCOAL MATERIAL TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Also do not see the report that the biphenyl and the indole of more than 95% that purity reaches

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] The raw material is rectified under the condition of vacuum degree of 74Kpa, theoretical plate number of rectification column of 40, and reflux ratio of 8 to enrich the indole biphenyl fraction, and obtain a biphenyl content of 27.3% and an indole content of 6.42%. indole biphenyl fraction. Then by indole biphenyl fraction: triethylene glycol: the mass ratio of n-heptane is 1: 0.5: 1 to carry out extraction, indole content is 20.53% in the indole extraction liquid after three-stage cross-flow extraction, and indole extraction rate 85.6% %. The indole extract is carried out rectification and purification under the condition that the vacuum degree is 74Kpa, the theoretical plate number of the rectification column is 40, and the reflux ratio is 8, and the indole product with a purity of 95.2% is obtained, and its single-pass yield is 85.6%. The triethylene glycol content is 98%, and the recovery rate is 95%. The biphenyl raffinate after extraction recovers n-heptane thro...

Embodiment 2

[0028] The indole biphenyl fraction enriched by rectification in Example 1 was extracted according to the mass ratio of indole biphenyl fraction:ethanolamine:n-hexane of 1:1:1. After the three-stage cross-flow extraction, the indole content in the indole extract was 21.63%, and the indole extraction rate was 89.6%. With regard to the indole extract, the rectification and purification are carried out under the conditions that the vacuum degree is 74Kpa, the theoretical plate number of the rectification column is 40, and the reflux ratio is 8, and the indole product with a purity of 95.4% is obtained, and its single-pass yield is 88.6%. The solvent ethanolamine content is 98%, and the recovery rate is 96%. The extracted biphenyl raffinate is simply distilled to recover n-hexane, with a purity of 99.5% and a recovery rate of 97%, for recycling; continue to operate under the conditions of a vacuum of 75KPa, a theoretical plate number of the rectification column of 40, and a reflux...

Embodiment 3

[0030] The raw material is rectified and enriched indole biphenyl fraction at a vacuum degree of 80Kpa, the theoretical plate number of the rectification tower is 40, and the reflux ratio is 6, and the indole biphenyl fraction with a biphenyl content of 27.07% and an indole content of 4.01% is obtained. Benzene fraction. Then carry out the six-stage countercurrent extraction process according to the mass ratio of indole biphenyl fraction: triethylene glycol: n-heptane in the ratio of 1:0.5:1. After extraction, the indole content is 17.98%, and the indole extraction rate is 98.2%. The indole extract is subjected to rectification and purification under the condition that the vacuum degree is 74Kpa, the theoretical plate number of the rectification column is 40, and the reflux ratio is 10, and the indole product with a purity of 95.2% is obtained, and its single-pass yield is 78.6%. The triethylene glycol content is 98%, and the recovery rate is 95%. The biphenyl raffinate recov...

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Abstract

The invention provides a method for extracting biphenyl and indole from the recycled wash oil of coal tar at the same time, which comprises the steps: (1) obtaining rich indole biphenyl fractions from the decompression and the rectification of the recycled wash oil; (2) carrying out multistage extraction and separation to the rich indole biphenyl fractions by using a double solvent extracting agent which comprises a polar solvent and a non-polar solvent, the weight ratio of the indole biphenyl fractions to the polar solvent to the non-polar solvent is 1:0.25 to 1:0.5 to 1.5 and the extraction temperature is 10 to 50 DEG C; (3) indole products are obtained by the rectified purification and the crystallized purification of the extraction solution; (4) biphenyl products are obtained by the rectified purification and the crystallized purification of the extraction solution. The method is simple and can extract and obtain highly pure biphenyl and indole from the recycled wash oil of the coal tar, which promotes the recycling value of the recycled wash oil of the coal tar, and the recycling use of the solvents reduces production cost, thus the method is suitable for industrial production.

Description

technical field [0001] The invention relates to a method for purifying biphenyl and indole, in particular to a method for extracting and purifying biphenyl and indole in coal tar, and more particularly to a method for simultaneously extracting biphenyl and indole from coal tar recovered washing oil. Background technique [0002] The mass fraction of biphenyl in coal tar is about 0.2-0.4%, most of which is concentrated in the wash oil fraction, and the mass fraction in the wash oil is about 8%. The content of indole in coal tar is 0.1-0.2%, mainly concentrated in washing oil fraction. Washing oil is one of the main fractions in the process of coal tar processing. The boiling point range of tar washing oil is 230-270°C. It is rich in organic chemical raw materials such as 2-methylnaphthalene, biphenyl, acenaphthene, indole and fluorene. Because of its good stability and solvency, washing oil is widely used in gas washing of benzene and washing and recovery of various organic ...

Claims

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Application Information

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IPC IPC(8): C07D209/06C07C7/04C07C7/10C07C15/14
Inventor 侯文杰汪旭郑胜华孙剑
Owner BAOWU CHARCOAL MATERIAL TECH CO LTD
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