Method for purifying dichloromethane

A dichloromethane and purification method technology, applied in the field of dichloromethane purification, can solve the problems of long time and low purity, and achieve the effects of stable product quality, high purity and high yield

Inactive Publication Date: 2012-10-24
TAICANG HUSHI REAGENT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0006] The technical problem to be solved by this invention is to provide a kind of purification method of dichloromethane, to overcome the low purity of dichloromethane purification product in the prior art, the deficiency of long time

Method used

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  • Method for purifying dichloromethane

Examples

Experimental program
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Effect test

Embodiment 1

[0019] Add 1000ml of industrial dichloromethane into a 2000ml single-necked flask, dropwise add 20ml of sulfuric acid with a mass fraction of 95%, shake until the acid layer remains colorless, add 400mL of 9.5% sodium carbonate solution for washing for 25min, separate Dichloromethane, add 30g of calcium hydride, heat and reflux for 1h, then add 40g4A molecular sieve for adsorption and purification for 20min, and finally carry out rectification and collection at a flow rate of 20mL / min to obtain 903mL of purified dichloromethane with a yield of 90.3% and a purity of 99.54%. .

Embodiment 2

[0021] Add 1000ml of industrial dichloromethane into a 2000ml single-necked flask, dropwise add 25ml of sulfuric acid with a mass fraction of 95%, shake until the acid layer remains colorless, add 500mL of 10% sodium carbonate solution for washing for 30min, separate Dichloromethane, add 40g of calcium hydride, heat and reflux for 1.5h, then add 50g4A molecular sieve for adsorption and purification for 25min, and finally carry out rectification and collection at a flow rate of 15mL / min to obtain purified dichloromethane 917mL with a yield of 91.7% and a purity of 99.71 %.

Embodiment 3

[0023] Add 1000ml of industrial dichloromethane into a 2000ml single-necked flask, dropwise add 30ml of sulfuric acid with a mass fraction of 98%, shake until the acid layer remains colorless, add 600mL of 10.5% sodium carbonate solution for washing for 35min, separate Dichloromethane, add 50g of calcium hydride, heat and reflux for 2h, then add 60g4A molecular sieve for adsorption and purification for 30min, and finally carry out rectification and collection at a flow rate of 10mL / min to obtain 929mL of purified dichloromethane with a yield of 92.9% and a purity of 99.9%. .

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Abstract

The invention discloses a method for purifying dichloromethane. The method comprises the steps of using industrial grade dichloromethane as a raw material, dropwise adding sulfuric acid with mass fraction of 95-98%, shaking, washing with sodium carbonate solution with mass fraction of 9.5-10.5% to separate the dichloromethane, then sequentially adding calcium hydride for drying and a 4A molecular sieve for adsorbing and purifying, and finally carrying out rectification for collecting purified dichloromethane. The purity of the dichloromethane obtained by the purifying method is higher than 99.5%. Compared with the prior art, the purifying process is safe, simple and convenient, energy is saced, emission is reduced, the added purifying agents can be recycled after treatment, requirements for green chemical industry and environment protection are met, and dichloromethane products obtained by the purifying method are stable in quality and have prospects of industrial production.

Description

technical field [0001] The present invention relates to a method for purifying dichloromethane, in particular to a method for purifying dichloromethane by using sulfuric acid with a mass fraction of 95-98%, sodium carbonate solution with a mass fraction of 9.5-10.5%, calcium hydride and 4A molecular sieves method. Background technique [0002] Dichloromethane is a compound formed by replacing two hydrogen atoms in the methane molecule with chlorine, and its molecular formula is CH 2 Cl 2 . Dichloromethane is a colorless, transparent, heavier than water, volatile liquid. It has an odor and sweetness similar to ether. It does not burn, but it is easy to form an explosive mixture when mixed with high concentration of oxygen. Slightly soluble in water, miscible with most commonly used organic solvents, miscible with other chlorinated solvents, ether, ethanol in any proportion. Dichloromethane has the advantages of strong solubility and low toxicity. It is widely used in the ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C19/03C07C17/38
Inventor 王伟顾小焱吕明王永旗
Owner TAICANG HUSHI REAGENT
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