Method for clean preparation H acid

A clean, sulfuric acid technology, applied in the preparation of sulfonic acid, organic chemistry, etc., can solve the problem of large waste water discharge, achieve the effects of reducing waste acid discharge, improving utilization, and reducing production and discharge

Active Publication Date: 2013-02-20
中国中化股份有限公司 +1
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Problems solved by technology

[0003] The object of the present invention is to provide a kind of clean preparation method of H acid,

Method used

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  • Method for clean preparation H acid
  • Method for clean preparation H acid
  • Method for clean preparation H acid

Examples

Experimental program
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Embodiment

[0045] Step 1: Sulfonation

[0046] Add 480 kg of concentrated sulfuric acid into a 500 liter reaction kettle, add 128 kg of refined naphthalene under stirring, slowly raise the temperature to 177-181°C, keep the temperature for 5 hours, then slowly cool down to 50°C, and control the temperature of the reaction solution to 50°C ~60°C, slowly drop 109 liters of water into the reaction solution, dilute the sulfonation reaction solution, and keep stirring at 60°C for 1 hour, filter and separate 2,6-naphthalene disulfonic acid, and analyze by liquid chromatography (area return One method, the same below) product content 90.17%, percent weight 95.6 kilograms.

[0047] The second step: nitrification

[0048] Concentrate the filtrate of the above-mentioned sulfonation reaction step under reduced pressure at a vacuum degree of -0.09MPa until the concentration of sulfuric acid is 93%, add 348 kg of concentrated sulfuric acid, then heat up to 35°C, slowly add 85 kg of 98% nitric acid d...

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Abstract

The invention discloses a method for clean preparation H acid. The method includes: adopting refined naphthalene as the raw material, using concentrated sulfuric acid to conduct sulfonation so as to prepare 2, 7-naphthalene disulfonic acid, separating the byproduct 2, 6-naphthalene disulfonic acid therein, and subjecting the 2, 7-naphthalene disulfonic acid to a nitration reaction in a sulfonation mother liquor directly to prepare 1, 8-dinitro-3, 6-naphthalene disulfonic acid; reusing the nitration mother liquor in a naphthalene sulfonation reaction step; and conducting hydrogenation reduction to prepare 1, 8-diamino-3, 6-naphthalene disulfonic acid, which is then subjected to acidic hydrolysis to prepare H acid. The nitration mother liquor and the hydrolysis mother liquor in the reaction can be recycled. An extraction process is employed to treat the repeatedly recycled mother liquors to remove the accumulated impurities therein. The method provided in the invention greatly reduces the wastewater generated in the H acid production process, by over 80% compared with the prior art, and at the same time can improve the product quality and yield.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a method for cleanly preparing H acid. Background technique [0002] H acid (1-amino-8-naphthol-3,6-disulfonic acid) is the most important organic intermediate in naphthalene series, mainly used in the production of products such as reactive dyes, direct dyes, acid dyes and color-changing acids, and Widely used in printing and dyeing, textile, cotton and chemical industries. In 1984, Japan first proposed the synthesis process of diamine method to prepare H acid: 2,7-naphthalene disulfonic acid obtained by disulfonation of refined naphthalene, and nitrated by mixed acid to generate 1,8-dinitro-3,6-naphthalene Disulfonic acid is then reduced with iron powder to obtain 1,8-diamino-3,6-naphthalene disulfonic acid, and finally H acid is prepared by hydrolysis. Although this process has made great progress in terms of product quality and yield compared with the traditiona...

Claims

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Application Information

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IPC IPC(8): C07C309/50C07C303/22
Inventor 马瑛王玉灿孟明扬徐飒英杨文东高嘉新刘东李春梅蒲爱军马文静欧云川
Owner 中国中化股份有限公司
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