Method for recovering dichloromethane

A dichloromethane and recovery method technology, which is applied in the field of recovery and application of chemical synthesis solvents, can solve problems such as high water content, inability to be directly applied, troublesome operation, etc., and achieve the effect of obvious rectification effect and low water content

Inactive Publication Date: 2014-02-05
ANHUI LANGXI LIANKE IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] There are many methods for dehydrating existing dichloromethane, which can be dehydrated by roughly three kinds of additives: alkaline dehydrating agent, acidic dehydrating agent and neutral dehydrating agent, basic dehydrating agent such as calcium hydride and acidic dehydrating agent, neutral dehydrating agent Agents such as molecular sieves; they can reduce the moisture in dichloromethane to about 0.5%: but the operation is cumbersome, and also involves the problem of recycling; therefore, by the above method, the water content of recovered dichloromethane is still relatively high , cannot be directly applied

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  • Method for recovering dichloromethane

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Experimental program
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Effect test

Embodiment 1

[0013] Firstly: add ethylene glycol to dichloromethane; secondly: put the mixture of dichloromethane and ethylene glycol into a rectification tower; finally: separate and purify the water of the dichloromethane to 0.5% through a rectification tower Below; Described ethylene glycol adopts direct addition method to join in the dichloromethane when adding.

[0014] Take 300ml of dichloromethane with a water content of 1.1%, add 5ml of ethylene glycol, rectify at atmospheric pressure (tower height 100mm), collect 39-41 degree fractions, collect a total of 240ml fractions, and have a moisture content of about 0.5%.

[0015] Be the experimental data of embodiment 1 below:

[0016] serial number Aqueous dichloromethane (ml) Amount of ethylene glycol (g) Fraction (ml) Moisture (%) 1 300 12 240 0.55 2 300 18 238 0.65 3 300 24 236 0.55 4 300 30 237 0.55

Embodiment 2

[0018] First: put dichloromethane into the rectifying tower; secondly: add ethylene glycol into the dichloromethane through the addition port of the rectifying tower, and finally: separate and purify the water of the dichloromethane through the rectifying tower to Below 0.5%; Described ethylene glycol adopts dropwise method to join in the dichloromethane when adding.

[0019] Be the experimental data of embodiment 2 below:

[0020]

[0021] The above data has been verified many times in the experiment, and the results show that ethylene glycol can achieve a good fractionation effect by fully exchanging gas-liquid through dripping, and the recovered water of dichloromethane can basically be controlled below 0.15%. The ethylene glycol can also be recycled.

[0022] The recovery method of dichloromethane of the present invention solves the difficult problem that dichloromethane and water can azeotrope in the prior art, even if a rectification tower is used, the moisture conte...

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Abstract

The invention discloses a method for recovering dichloromethane. Ethylene glycol is added to the dichloromethane, and is treated through a rectifying tower, so that the moisture of the dichloromethane is separated and purified to below 0.5%. By adopting the method for recovering the dichloromethane, which is disclosed by the invention, the problem that the dichloromethane and water are azeotropic together in the prior art to cause that the moisture of the dichloromethane cannot be easily kept below 0.5% even if the rectifying tower is utilized is solved. The dichloromethane has a significant rectification effect and is low in moisture by adding the ethylene glycol, and can be directly recovered and reused.

Description

technical field [0001] The invention relates to a method for recovering chemical synthesis solvents, in particular to a method for recovering dichloromethane. Background technique [0002] As a chemical synthetic solvent, dichloromethane has the advantages of strong solvency and low toxicity. Molding agents and paint removers and other products; because dichloromethane has a small amount of toxicity, the recovery method and application of dichloromethane are particularly important, especially in industrial production, the recovery and application of dichloromethane can be larger Substantial cost reduction. [0003] There are many methods for dehydrating existing dichloromethane, which can be dehydrated by roughly three kinds of additives: alkaline dehydrating agent, acidic dehydrating agent and neutral dehydrating agent, basic dehydrating agent such as calcium hydride and acidic dehydrating agent, neutral dehydrating agent Agents such as molecular sieves; they can reduce t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C19/04C07C17/386
Inventor 贾玉梁
Owner ANHUI LANGXI LIANKE IND
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