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Method for recovering o-dichlorobenzene through sulfonation process of bromamine acid produced by solvent method

A technology of o-dichlorobenzene and bromo-amino acid, applied in the direction of disproportionation separation/purification of halogenated hydrocarbons, etc., can solve the problems of high production cost of bromo-amino acid, pollution of organic solvents, high energy consumption, etc.

Inactive Publication Date: 2012-06-27
YANCHENG OUHUA CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method consumes a lot of energy, and the recovery rate of o-dichlorobenzene is not high, only about 90%, which leads to high production cost of bromonic acid, and causes organic solvent pollution at the same time

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0015] Put 100 parts of 1-aminoanthraquinone into 700 parts of o-dichlorobenzene and stir to form a slurry, heat up to 80°C,

[0016] Add 65 parts of chlorosulfonic acid dropwise; after the dropwise addition, slowly raise the temperature to 125-130°C, keep warm for 3 hours for sulfonation reaction; Stand still at 65-75°C for more than 4 hours, and carefully separate the acid layer. Add 50 parts of sulfuric acid to the ortho-dichlorobenzene layer for washing, and separate the washing acid and o-dichlorobenzene at rest; combine the separated acid layer and washing acid, vacuumize to make the vacuum degree reach -60 kPa, heat to 90°C, and depressurize Recover ortho-dichlorobenzene by distillation. The 1-aminoanthraquinone-2-sulfonic acid sulfuric acid solution that evaporates o-dichlorobenzene can be directly brominated. A total of 696.5 parts of ortho-dichlorobenzene were separated and recovered by vacuum distillation, with a recovery rate of 99.5%.

[0017]

Embodiment 2

[0019] Same as Example 1, changed to add 350 parts of 98% sulfuric acid, and a total of 689 parts of o-dichlorobenzene were recovered, with a recovery rate of 98.4%.

[0020]

Embodiment 3

[0022] Same as Example 1, changed to add 450 parts of 96% sulfuric acid, and a total of 694 parts of o-dichlorobenzene were recovered, with a recovery rate of 99.1%.

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Abstract

The invention relates to a method for recovering o-dichlorobenzene through a sulfonation process of bromamine acid produced by a solvent method, which comprises the following steps of: after 1-amino-anthraquinone is sulfonated by the chlorosulfonic acid in an o-dichlorobenzene solvent, adding 93-96 percent of sulfuric acid to extract 1-amino-anthraquinone-2-sulfonic acid from an o-dichlorobenzene layer; and carrying out distilling under reduced pressure on sulfuric acid solution to recover the o-dichlorobenzene. The sulfuric acid solution recovering the o-dichlorobenzene can be directly bromized. The method has the beneficial effects that the recovery rate of the o-dichlorobenzene reaches above 98 percent, the recovery rate of the solvent o-dichlorobenzene is greatly improved, the emission of an organic solvent is reduced, the environment is protected, and meanwhile, the energy consumption is low.

Description

technical field [0001] The invention relates to a method for recovering o-dichlorobenzene in the production of bromic acid by a solvent method. [0002] Background technique [0003] Bromonic acid (4-bromo-1-aminoanthraquinone-2-sulfonic acid) is an important intermediate for the synthesis of dyes and pigments. Bromic acid is obtained by sulfonating 1-aminoanthraquinone to 1-aminoanthraquinone-2 sulfonic acid, and then brominated to obtain bromic acid. Existing production techniques include sulfuric acid method and solvent method. The difference between the two processes is mainly in the sulfonation process. The former is to sulfonate 1-aminoanthraquinone with oleum, while the latter is to use oleum in o-dichlorobenzene solvent. Chlorosulfonic acid sulfonation. [0004] The traditional sulfonated solvent method for reclaiming o-dichlorobenzene is to add the reaction mixture to the alkali solution after the sulfonation reaction is completed, adjust the pH to about 7, and t...

Claims

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Application Information

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IPC IPC(8): C07C25/08C07C17/38
Inventor 杨思卫李彦张劲松
Owner YANCHENG OUHUA CHEM IND
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