Decolorization method for recycling vinyl benzene with abstraction distillation

A technology of extractive distillation and styrene, applied in the direction of distillation purification/separation, chemical transformation purification/separation, organic chemistry, etc., can solve problems such as solid waste and complex process, high equipment requirements, and complicated process

Active Publication Date: 2009-05-13
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is a large amount of solid waste and complex process brought by white clay decolorization in the prior art, or the problems of high equipment requirements and c

Method used

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  • Decolorization method for recycling vinyl benzene with abstraction distillation

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] After the decolorizing agent maleic acid and N-formylmorpholine are mixed and dissolved, they enter the extractive distillation tower with 30 theoretical plates, the feeding position is the 4th theoretical plate, and the amount of decolorizing agent is 1 / 2 of the raw oil feed amount. 3%, the feed position of raw oil is the 15th theoretical plate, the reflux ratio is 5, the operating pressure of the extractive distillation tower is 10KPa, the temperature at the top of the tower is controlled at 73.5~75°C, and the top of the tower obtains light oil with a lower boiling point than styrene. Components, light component chromaticity (in platinum cobalt chromaticity unit, the same below) is 50, and the tower still is styrene and solvent mixture, and this mixture enters the solvent recovery tower that the number of theoretical plates is 10, and the feeding position is the first 5 theoretical plates, the reflux ratio is 5, the operating pressure of the solvent recovery tower is 1...

Embodiment 2

[0016] After the decolorizing agent maleic anhydride and N-methylpyrrolidone are mixed and dissolved, they enter the extractive distillation tower with a theoretical plate number of 60, the feeding position is the sixth theoretical plate, and the amount of the decolorizing agent is 1% of the feed amount of the raw material oil. %, the feeding position of raw oil is the 30th theoretical plate, the reflux ratio is 1, the operating pressure of the extractive distillation tower is 12KPa, the temperature at the top of the tower is controlled at 76-78°C, and the light group with a lower boiling point than styrene is obtained at the top of the tower points, the chromaticity of light components (calculated in platinum cobalt chromaticity units, the same below) is 80, and the tower kettle is a mixture of styrene and solvent, and the mixture enters a solvent recovery tower with a theoretical plate number of 30, and the feed position is the 15 A theoretical plate, the reflux ratio is 3, t...

Embodiment 3

[0018] After the decolorizing agent acetic anhydride and sulfolane are mixed and dissolved, they enter the extractive distillation tower with 80 theoretical plates. It is the 40th theoretical plate, the reflux ratio is 0.5, the operating pressure of the extractive distillation tower is 8KPa, the temperature at the top of the tower is controlled at 66-67.5°C, the light component with a lower boiling point than styrene is obtained at the top of the tower, and the light component chromaticity (in platinum cobalt chromaticity unit, the same below) is 100, and the tower still is styrene and solvent mixture, and this mixture enters the solvent recovery tower that theoretical plate number is 50, and feed position is the 25th theoretical plate, and reflux ratio is 1. The operating pressure of the solvent recovery tower is 8KPa, and the temperature at the top of the tower is controlled at 69.5-72°C. Crude styrene with a chroma of 10 is obtained at the top of the tower. Refined styrene ...

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Abstract

The invention relates to a decoloring method for reclaiming styrene by means of extraction and rectification, which mainly solves the problems of a large quantity of solid waste and complex technology caused by adoption of gumbrine for decolorization or high equipment requirement and complex flow caused by adoption of a nitric acid for decolorization. The decoloring method comprises the following steps: a decoloring agent is added into a solvent and mixed and dissolved to obtain a material one; the material one and styrene-bearing raw oil enter into the upper part and the middle part of a rectification tower respectively; light constituents the boiling point of which is lower than that of the styrene are rectified on the top of the tower, and the chrominance of the light constituents is less than or equal to 100 as calculated by the platinum-cobalt chrominance unit; a mixture material two of the styrene and the solvent is obtained at the bottom of the tower, wherein the decoloring agent is selected from at least one of an organic acid or organic anhydride, and the solvent is selected from at least one among polar solvents the boiling point of which is more than 160 DEG C; the material two enters into the middle of a solvent reclaiming tower, coarse styrene the chrominance of which is less than or equal to 10 as calculated by the platinum-cobalt chrominance unit is rectified on the top of the tower, and a reclaimed solvent is obtained at the bottom of the tower; and the coarse styrene enters into the middle of a refined styrene tower, pure styrene the chrominance of which is less than or equal to 10 as calculated by the platinum-cobalt chrominance unit is rectified on the top of the tower, and heavy constituents the boiling point of which is higher than that of the styrene are obtained at the bottom of the tower. The technical proposal well solves the problems.

Description

technical field [0001] The invention relates to a decolorization method for extracting and rectifying recovery of styrene. Background technique [0002] In the ethylene cracking unit using naphtha as raw material, the content of xylene is 0.06-0.07 tons / ton of ethylene, while pyrolysis gasoline C 8 The ratio of xylene:styrene:ethylbenzene in the distillate is usually 4:3:1. According to this calculation, a set of 600,000 tons / year ethylene plant can recover about 29,000 tons / year of styrene. If the ethylbenzene is dehydrogenated and recovered, the output of styrene can be increased, which has a certain recovery value. The recovery of styrene from pyrolysis gasoline can eliminate the hydrogen consumption of styrene hydrogenation in traditional pyrolysis gasoline units, thereby reducing the load on hydrogenation units; the ethylbenzene content in recovered mixed xylene is greatly reduced, which can be used as xylene isomerization Raw material for the production of p-xylene; ...

Claims

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Application Information

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IPC IPC(8): C07C15/46C07C7/148C07C7/04
Inventor 钟禄平肖剑郭艳姿陈秀宏卢咏琰
Owner CHINA PETROLEUM & CHEM CORP
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