Technique for reducing impurity content in gas phase hydrogenchloride from hydrolysis of dimethyldichlorosilane

A technology of dimethyldichlorosilane and impurity content, applied in the direction of chlorine/hydrogen chloride, chlorine/hydrogen chloride purification, etc., can solve the problems of reducing pressure, unable to synthesize with chloromethane, etc., avoiding treatment, low equipment cost, reducing impurities The effect of content

Inactive Publication Date: 2009-05-06
浙江恒业成有机硅有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The synthesis of methyl chloride has certain requirements on the pressure of hydrogen chloride gas. Therefore, the purification of hydrogen chloride gas cannot reduce its pressure too much, otherwise it will not be used for the synthesis of methyl chloride.

Method used

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  • Technique for reducing impurity content in gas phase hydrogenchloride from hydrolysis of dimethyldichlorosilane

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0017] Such as figure 1 As shown, a secondary device is used to separate impurities. The gas-liquid separator 1 hydrolyzes dimethyldichlorosilane to produce mixed hydrogen chloride gas through the pipeline a and first enters the scrubber 2 of the diversion structure, and the scrubber 2 adopts supercooled saturation Hydrochloric acid enters the washing tower 2 from the top pipeline d for spray washing, and at the same time lowers the gas temperature at -25°C to remove most of the impurities, and the washed concentrated hydrochloric acid flows out from the tower bottom pipeline e; The hydrogen chloride gas is passed into the bottom of the demister 3 through the pipeline b, and the adsorption medium of the inner layer of the demister 3 is a porous fiber, which absorbs the siloxane impurities in the hydrogen chloride gas, and then mixes the siloxane impurities with the The hydrogen chloride gas is separated, and the liquid droplets adsorbed by the demister 3 flow back into the vap...

Embodiment 2

[0019] Such as figure 1 As shown, a secondary device is used to separate impurities. The gas-liquid separator 1 hydrolyzes dimethyldichlorosilane to produce mixed hydrogen chloride gas through the pipeline a and first enters the scrubber 2 of the diversion structure, and the scrubber 2 adopts supercooled saturation Hydrochloric acid enters the washing tower 2 from the top pipeline d for spray washing, and at the same time lowers the gas temperature at -30°C to remove most of the impurities, and the washed concentrated hydrochloric acid flows out from the tower bottom pipeline e; The hydrogen chloride gas is passed into the bottom of the demister 3 through the pipeline b, and the adsorption medium of the inner layer of the demister 3 is a porous fiber, which absorbs the siloxane impurities in the hydrogen chloride gas, and then mixes the siloxane impurities with the The hydrogen chloride gas is separated, and the liquid droplets adsorbed by the demister 3 flow back into the vap...

Embodiment 3

[0021] Such as figure 1 As shown, a secondary device is used to separate impurities. The gas-liquid separator 1 hydrolyzes dimethyldichlorosilane to produce mixed hydrogen chloride gas through the pipeline a and first enters the scrubber 2 of the diversion structure, and the scrubber 2 adopts supercooled saturation Hydrochloric acid enters the washing tower 2 from the top pipeline d for spray washing, and at the same time lowers the gas temperature at -40°C to remove most of the impurities, and the washed concentrated hydrochloric acid flows out from the tower bottom pipeline e; The hydrogen chloride gas is passed into the bottom of the demister 3 through the pipeline b, and the adsorption medium of the inner layer of the demister 3 is a porous fiber, which absorbs the siloxane impurities in the hydrogen chloride gas, and then mixes the siloxane impurities with the The hydrogen chloride gas is separated, and the liquid droplets adsorbed by the demister 3 flow back into the vap...

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Abstract

The invention discloses a process method used for reducing the content of impurities in gas-phase hydrogen chloride after hydrolysis of dichlorodimethyl silane, comprising the steps as follows: a two-step device is used for separating the impurities; a vapour liquid separator leads the mixed hydrogen chloride gas generated after the hydrolysis of dichlorodimethyl silane to enter a washing tower of a guide structure so as to remove most of impurities; subsequently, the hydrogen chloride gas with most of impurities removed is arranged into the bottom of a demister; the adsorption medium at the internal layer of the demister is porous fiber which is used to adsorb the siloxane impurity in the hydrogen chloride gas; and the hydrogen chloride gas with the siloxane impurity removed is sent to a methyl chloride device to carry out the subsequent process. The method reduces the content of the impurities in the hydrogen chloride gas, improves the yield of hydrolysate of the dichlorodimethyl silane, keeps the pressure of the hydrogen chloride gas at a high level after purification, does not generate a great deal of waste acid, avoids the disposal of waste acid, and has low energy consumption and low equipment expense.

Description

technical field [0001] The invention relates to a process for reducing the impurity content in gas-phase hydrogen chloride hydrolyzed by dimethyldichlorosilane. Background technique [0002] Dimethyldichlorosilane hydrolysis is an important step in silicone production. The dimethyldichlorosilane produced by the synthesis unit is hydrolyzed to become polydimethylsiloxane hydrolyzate, and then undergoes a series of post-processing to produce polydimethylcyclosiloxane. Polydimethylcyclosiloxane is an important raw material in the silicone industry and is used to produce various silicone oils, silicone rubbers, etc. [0003] In the dimethyldichlorosilane hydrolysis process, the concentrated acid hydrolysis process is more advanced. The process produces hydrogen chloride gas directly. However, the hydrogen chloride gas generally contains about 2000 ppm of impurities, and these impurities include water, incompletely reacted methylsilane monomers, linear siloxanes, and the like....

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C01B7/07
Inventor 甘腾飞吴忆南常东方郑礼平冯旭初
Owner 浙江恒业成有机硅有限公司
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