Dimethyl malonate industrial wastewater treatment and resource recovery method

A technology for dimethyl malonate and waste water production, which is applied to chemical instruments and methods, preparation of organic compounds, ammonia compounds, etc., can solve problems such as waste of resources, environmental pollution, etc., and achieves reduction of environmental protection pressure, production cost, Effective use of the effect

Inactive Publication Date: 2013-12-11
CHONGQING UNISPLENDOUR CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The production process produces a certain amount of waste water, which contains a large amount of useful resources such as methanol, sulfuric acid, and ammonium bisulfate. Failure to recycle it will not only cause a great waste of resources, but also seriously pollute the environment

Method used

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  • Dimethyl malonate industrial wastewater treatment and resource recovery method
  • Dimethyl malonate industrial wastewater treatment and resource recovery method

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Experimental program
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Effect test

Embodiment 1

[0023] The following will refer to figure 1 , further illustrate the present invention by embodiment 1:

[0024] (1) Methanol recovery: 2000kg of dimethyl malonate production wastewater (8.6% methanol content, equivalent to 172kg; 23.5% sulfuric acid content, equivalent to 470kg; 32.4% ammonium bisulfate content, equivalent to 640.8kg) was transferred to the rectification tower, Atmospheric distillation yielded 152kg of methanol with a content of 99.3%, a water content of 0.2%, and a recovery rate of 87.8%;

[0025] (2) Neutralization: Transfer the wastewater after recovering methanol to the neutralization reactor, lower it to room temperature, keep the temperature not exceeding 60°C, and pass through ammonia gas to neutralize to pH=5.5;

[0026] (3) Recovery of ammonium sulfate: steam 150kg of neutralized waste water under reduced pressure, then cool to 0°C to crystallize, then centrifuge to obtain solid ammonium sulfate, wash with 100kg of water, and dry to obtain 978kg of ...

Embodiment 2

[0028] The following will refer to figure 2 , further illustrate the present invention by embodiment 2:

[0029] (1) Neutralization: Transfer 2000kg of dimethyl malonate production wastewater (8.6% methanol content, equivalent to 172kg; 23.5% sulfuric acid content, equivalent to 470kg; 32.4% ammonium bisulfate content, equivalent to 640.8kg) to the neutralization reactor , keep the temperature not exceeding 60°C and pass through ammonia gas to neutralize to pH=5.7;

[0030] (2) Methanol recovery: transfer the neutralized wastewater to a rectification tower, and rectify at atmospheric pressure to obtain 149kg of methanol, with a content of 99.1%, a water content of 0.3%, and a recovery rate of 85.7%;

[0031] (3) Ammonium sulfate recovery: Distill 150kg of water from the waste water after recovery of methanol under reduced pressure, then cool to 0°C to crystallize, then centrifuge to obtain solid ammonium sulfate, wash with 100kg of water, and dry to obtain 985kg of ammonium ...

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Abstract

The invention discloses a dimethyl malonate industrial wastewater treatment and resource recovery method which comprises the steps of recovering methyl alcohol through rectifying, neutralizing ammonia and recovering ammonium sulfate through concentrating and crystalizing, or comprises the steps of neutralizing ammonia, recovering methyl alcohol through rectifying, and recovering ammonium sulfate through concentrating and crystalizing. According to the invention, the recovery rate of the methyl alcohol in one batch is more than 85%, the recovered methyl alcohol can be used indiscriminately in the production of dimethyl malonate, the recovery rate of the ammonium sulfate in one batch is more than 70%, the ammonium sulfate can be sold as a by-product, the raffinate left after the methyl and the ammonium sulfate are recovered can be continuously used indiscriminately in the extraction split-phase stage in the production of the dimethyl malonate, due to the treatment with the method provided by the invention, no high-concentration wastewater is discharged in the production of the dimethyl malonate, the useful resources are effectively utilized, the environmental pressure and the production cost are reduced, and the economical effect and the environmental protection effect are remarkable.

Description

technical field [0001] The invention relates to a method for treating waste water in chemical production, in particular to a method for treating waste water in dimethyl malonate production and recycling resources. Background technique [0002] Dimethyl malonate is an intermediate of medicines, pesticides and dyes. At present, there are many production methods at home and abroad. In China, cyanation esterification is mainly used, that is, chloroacetic acid, sodium cyanide and methanol are used as raw materials, and after neutralization , cyanidation, acidification, esterification, and finally extraction and separation to obtain dimethyl malonate. The production process produces a certain amount of waste water, which contains a large amount of useful resources such as methanol, sulfuric acid, and ammonium bisulfate. Failure to recycle it will not only cause a great waste of resources, but also seriously pollute the environment. [0003] Every ton of dimethyl malonate produces...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C31/04C07C29/80C01C1/242C01C1/246
Inventor 丁永良郑道敏姚如杰刘佳范倩玉罗延谷张飞屈洋李朝全
Owner CHONGQING UNISPLENDOUR CHEM
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