Dimethyldichlorosilane hydrolysis hydrogen chloride treatment device for high-pressure chloromethane synthesis

Abstract

The utility model provides a dimethyl dichlorosilane hydrolysis hydrogen chloride treatment device for high-pressure chloromethane synthesis, which is characterized in that a top outlet of a hydrogen chloride gas washing tower is connected with an inlet of a gas-liquid separation tank through a pipeline, a top outlet of the gas-liquid separation tank is connected with a hydrogen chloride cooler, and the hydrogen chloride cooler is connected with a demister; the demister is connected with the purification tower through the hydrogen chloride preheater, the top of the purification tower is connected with the compressor buffer tank, and the compressor buffer tank is connected with the hydrogen chloride compressor. The dried hydrogen chloride gas is conveyed to a demister, mist particles with the diameter larger than 1 micron are directly intercepted by utilizing an adsorption medium of an internal FRP + glass fiber mixed material, mist particles with the diameter smaller than 1 micron are adsorbed and fixed, sulfuric acid mist carried by the hydrogen chloride gas can be removed, finally, the purified hydrogen chloride gas is compressed, and pure hydrogen chloride gas with the pressure of 0.2-0.4 MPa is obtained. And a guarantee is provided for a co-production chloromethane synthesis process.

Description

TECHNICAL FIELD

[0001] The utility model relates to a chemical technology field, concretely relates to a kind of dimethyl dichlorosilane hydrolysis hydrogen chloride processing device for high-pressure chloromethane synthesis. BACKGROUND

[0002] Organosilicon, a kind of multi-functional high polymer material, has the unique structure with silicon-oxygen bond (Si-O-Si) as skeleton, which makes it have the performance of inorganic material and organic material, and can be widely used in chemical industry, medicine, electronics and electrical appliances, building and other fields.

[0003] Dimethyl dichlorosilane hydrolysis (abbreviation: dimethyl hydrolysis) as one of important links of organosilicon monomer production, mainly adopts low-energy consumption concentrated acid hydrolysis process in industry, which has the characteristics of directly by-product hydrogen chloride gas as chloromethane synthesis raw material, realizing the recycling of chlorine, but the existing process technology, hydrogen chloride gas by-product of dimethyl hydrolysis is easy to carry small molecule siloxane impurities and moisture, causing the cooler, water washing tower and other equipment of chloromethane synthesis process to be glued, pipe is blocked, increases the difficulty and frequency of maintenance, leads to high operation and maintenance cost, affects the reaction efficiency and product quality of chloromethane, and simultaneously easily causes the by-product dilute hydrochloric acid waste acid of chloromethane synthesis process to have high content. Therefore, purification treatment is carried out on hydrogen chloride gas by-product of dimethyl hydrolysis, and a certain pressure of feeding hydrogen chloride gas is ensured, which is beneficial to the safe and stable production of high-pressure chloromethane synthesis and increases the economic value of enterprise. SUMMARY

[0004] In view of the above technical limitations, the utility model provides a kind of dimethyl dichlorosilane hydrolysis hydrogen chloride processing device for high-pressure chloromethane synthesis to improve the reaction efficiency and product purity of high-pressure chloromethane synthesis, reduce the maintenance cost of subsequent equipment, reduce energy consumption and waste acid discharge.

[0005] The utility model relates to a kind of dimethyl dichlorosilane hydrolysis hydrogen chloride processing device for high-pressure chloromethane synthesis, hydrogen chloride gas washing tower top outlet is connected with the gas-liquid separation tank import by pipeline, the gas-liquid separation tank top outlet is connected with hydrogen chloride cooler, hydrogen chloride cooler is connected with demister;

[0006] Demister is connected with purification tower by hydrogen chloride preheater, purification tower top is connected with compressor buffer tank, and compressor buffer tank is connected with hydrogen chloride compressor.

[0007] Hydrogen chloride gas washing tower middle part is connected with circulating pump by pipeline, circulating pump is connected with hydrochloric acid cooler, and the refrigerant pipeline of hydrochloric acid cooler is deep into the upper portion in hydrogen chloride gas washing tower, and is provided with spray head, realizes that refrigerant is sprayed from tower top, removes part of siloxane impurities, and realizes circulation.

[0008] The hydrogen chloride gas scrubber tower top outlet is connected with the demister through a pipeline.

[0009] The gas-liquid separation tank, hydrogen chloride cooler and demister outlet are connected with the separator through a pipeline.

[0010] The hydrogen chloride gas scrubber tower bottom outlet is connected with the separator through a pipeline.

[0011] The top of the purification tower is connected with the purification tower demister, and the purification tower demister is connected with the compressor buffer tank.

[0012] The demister is connected with the purification tower demister through a pipeline, and the purification tower demister is connected with the compressor buffer tank.

[0013] The bottom outlet of the purification tower and the purification tower demister is connected with the circulating pump through a pipeline, and then connected to the purification tower circulating cooler and dilute sulfuric acid storage area respectively, and the purification tower circulating cooler is connected with the middle inlet of the purification tower. The purification tower is provided with a concentrated sulfuric acid inlet pipeline.

[0014] The bottom outlet of the compressor buffer tank is connected with the liquid discharge pipe, and the liquid discharge pipe is connected to the storage tank area through the compressor buffer tank liquid discharge pump.

[0015] The main process includes the following: the by-product hydrogen chloride gas containing small molecule siloxane impurities and water produced by the hydrolysis of dimethyl concentrated acid enters the pachuca ring packed tower, and the supercooled saturated hydrochloric acid cooled by-35℃ refrigerant is sprayed into the hydrogen chloride gas produced by hydrolysis (the temperature of the cooled saturated hydrochloric acid is-1℃~-25℃), so that the siloxane impurities are absorbed and condensed by the supercooled saturated hydrochloric acid and recovered to remove part of the siloxane impurities.

[0016] Then the impurity-removed hydrogen chloride gas mixture is transported to the gas-liquid separation tank and the hydrogen chloride cooler of-35℃ refrigerant medium for deep condensation (hydrogen chloride is deep cooled to-10℃~-25℃), to remove part of the water, and separate the gas and liquid phases.

[0017] The dried hydrogen chloride gas is transported to a demister, the mist particles with a diameter greater than 1 um are directly intercepted by using the adsorption medium of the internal FRP+glass fiber mixed material, the mist particles with a diameter less than 1 um are adsorbed and fixed, so that the purpose of purifying the hydrogen chloride gas is achieved, and then the hydrogen chloride gas is transported to a drying tower, and concentrated sulfuric acid is introduced into the drying tower, the strong oxidizing property of the concentrated sulfuric acid is used to cross-link with the siloxane with low molecular weight, the volatility of the siloxane is further reduced and absorbed, meanwhile, the water absorption of the concentrated sulfuric acid is used for further drying treatment, and the hydrogen chloride gas with siloxane impurities less than 20 ppm and water content less than 5 ppm is obtained after the demister of the purification tower, the adsorption medium in the demister of the purification tower is 316L+glass fiber mixed material, the sulfuric acid mist entrained in the hydrogen chloride gas can be removed, and finally the purified hydrogen chloride gas can be transported to the buffer tank before the compressor and the hydrogen chloride compressor by using the stainless steel pipeline instead of the fluorine-lined pipeline, and the pure hydrogen chloride gas with a pressure of 0.2-0.4 Mpa is obtained, which provides guarantee for the co-production of chloromethane synthesis process.

[0018] If the impurities are not removed during drying, it is difficult to use the pipeline made of stainless steel, and it is necessary to use the expensive fluorine-lined pipeline, and even if the expensive fluorine-lined pipeline is used, the hydrogen chloride gas with pressure formed in the compression process is also difficult to use as downstream.

[0019] The siloxane impurity content in the hydrogen chloride gas with pressure obtained by the technical scheme of the present application is less than 1 ppm, and is further preferably less than 0.1 ppm; the water content is less than 1 ppm, and is further preferably less than 0.1 ppm. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a kind of for high pressure chloromethane synthesis dimethyldichlorosilane hydrolysis hydrogen chloride processing device, wherein 1 is hydrogen chloride gas washing tower, 2 is gas-liquid separation tank, 3-1 hydrogen chloride cooler, 3-2 hydrochloric acid cooler, 4 demister, 5 is demister, 6 hydrogen chloride preheater, 7 purification tower, 8 demister of purification tower, 9 compressor buffer tank, 10 liquid discharge pipe, 11 hydrogen chloride compressor, 12 purification tower circulating cooler. DETAILED DESCRIPTION

[0021] Example 1

[0022] A kind of for high pressure chloromethane synthesis dimethyldichlorosilane hydrolysis hydrogen chloride processing device, hydrogen chloride gas washing tower 1 top outlet is connected with gas-liquid separation tank 2 import by pipeline, gas-liquid separation tank 2 top outlet is connected with hydrogen chloride cooler 3-1, hydrogen chloride cooler 3-1 is connected with demister 4;

[0023] The defoamer 4 is connected with the purification tower 7 through the hydrogen chloride preheater 6, the top of the purification tower 7 is connected with the compressor buffer tank 9, and the compressor buffer tank 9 is connected with the hydrogen chloride compressor 11. The purification tower 7 is provided with a concentrated sulfuric acid inlet pipeline.

[0024] The middle part of the hydrogen chloride gas washing tower 1 is connected with a circulating pump through a pipeline, the circulating pump is connected with a hydrochloric acid cooler 3-2, the refrigerant pipeline of the hydrochloric acid cooler 3-2 extends to the upper part in the hydrogen chloride gas washing tower 1, and is provided with a spray head, so that the refrigerant is sprayed from the top of the tower for washing, part of the siloxane impurities is removed, and circulation is realized.

[0025] The top outlet of the hydrogen chloride gas washing tower 1 is also connected with the defoamer 4 through a pipeline.

[0026] The outlets of the gas-liquid separation tank 2, the hydrogen chloride cooler 3-1 and the defoamer 4 are connected with the separator 5 through pipelines.

[0027] The bottom outlet of the hydrogen chloride gas washing tower 1 is connected with the separator 5 through a pipeline.

[0028] The top of the purification tower 7 is connected with the purification tower defoamer 8, and the purification tower defoamer 8 is connected with the compressor buffer tank 9.

[0029] The defoamer 4 is connected with the purification tower defoamer 8 through a pipeline, and the purification tower defoamer 8 is connected with the compressor buffer tank 9.

[0030] The bottom outlets of the purification tower 7 and the purification tower defoamer 8 are connected with a circulating pump through pipelines, and then connected to a purification tower circulating cooler 12 and a dilute sulfuric acid storage area respectively, and the purification tower circulating cooler 12 is connected with the middle inlet of the purification tower 7.

[0031] The bottom outlet of the compressor buffer tank 9 is connected with a liquid discharge pipe 10, and the liquid discharge pipe 10 is connected to a storage tank area through a compressor buffer tank liquid discharge pump.

[0032] As Figure 1, the by-product hydrogen chloride gas containing small molecule siloxane impurities and moisture generated by hydrolysis of dimethyl concentrated acid enters the Pall ring packed washing tower 1, and is fully contacted with the subcooled saturated hydrochloric acid (-35℃ coolant spray) circulating inside the hydrochloric acid cooler 3-2 in the washing tower for gas-liquid mass transfer, at this time the hydrogen chloride gas temperature is reduced to -5.5℃, so that the siloxane impurities are absorbed and condensed by the subcooled saturated hydrochloric acid and recovered to remove part of the siloxane impurities, then the hydrogen chloride gas mixture after impurity removal is transported to the gas-liquid separation tank 2 and the hydrogen chloride cooler 3-1 (-35℃ coolant) for deep condensation, -14.5℃ to remove moisture, and then the dried hydrogen chloride gas is transported to the demister 4, which uses the adsorption medium of internal FRP+glass fiber mixed material to directly intercept the mist particles with a diameter greater than 1um and adsorb and fix the mist particles with a diameter less than 1um, so as to achieve the purpose of purifying the hydrogen chloride gas, and then it is transported to the purification tower 7, and concentrated sulfuric acid is introduced into the inside of the drying tower, which uses the strong oxidizing property of concentrated sulfuric acid to crosslink with low molecular weight siloxane, further reduces the volatility of siloxane and absorbs, and at the same time uses the water absorption of concentrated sulfuric acid to further dry, and after the demister 8 of the purification tower, hydrogen chloride gas with siloxane impurities less than 20ppm and moisture content less than 5ppm is obtained, the internal adsorption medium of the demister is 316L+glass fiber mixed material, which can remove the sulfuric acid mist entrained by the hydrogen chloride gas, and finally the purified hydrogen chloride gas can be transported to the compressor buffer tank 9 and the hydrogen chloride compressor 11 using stainless steel pipe instead of fluorine-lined pipe, and pure hydrogen chloride gas with a pressure of 0.2-0.4Mpa is obtained, which provides guarantee for the co-production of chloromethane synthesis process.

[0033] Table 1 Purification effect of hydrogen chloride gas

[0034]

Claims

1. A dimethyldichlorosilane hydrolysis hydrogen chloride treatment apparatus for high-pressure chloromethane synthesis, characterized by, The outlet at the top of the hydrogen chloride gas washing tower (1) is connected with the inlet of the gas-liquid separation tank (2) through a pipeline, the outlet at the top of the gas-liquid separation tank (2) is connected with the hydrogen chloride cooler (3-1), the hydrogen chloride cooler (3-1) is connected with the demister (4); The demister (4) is connected with the purification tower (7) through the hydrogen chloride preheater (6), the top of the purification tower (7) is connected with the compressor buffer tank (9), and the compressor buffer tank (9) is connected with the hydrogen chloride compressor (11).

2. The dimethyldichlorosilane hydrolysis hydrogen chloride treatment apparatus for high-pressure chloromethane synthesis according to claim 1, characterized by, The middle part of the hydrogen chloride gas washing tower (1) is connected with a circulating pump through a pipeline, the circulating pump is connected with the hydrochloric acid cooler (3-2), the refrigerant pipeline of the hydrochloric acid cooler (3-2) extends into the upper part of the hydrogen chloride gas washing tower (1) and is provided with a spray head, so that the refrigerant is sprayed from the top of the tower for washing, part of the siloxane impurities are removed, and circulation is realized.

3. The dimethyldichlorosilane hydrolysis hydrogen chloride treatment apparatus for high-pressure chloromethane synthesis according to claim 1, characterized by, The outlet at the top of the hydrogen chloride gas washing tower (1) is also connected with the demister (4) through a pipeline.

4. The dimethyldichlorosilane hydrolysis hydrogen chloride treatment apparatus for high-pressure chloromethane synthesis according to claim 1, characterized by, The outlets of the gas-liquid separation tank (2), the hydrogen chloride cooler (3-1) and the demister (4) are connected with the separator (5) through pipelines.

5. The dimethyldichlorosilane hydrolysis hydrogen chloride treatment apparatus for high-pressure chloromethane synthesis according to claim 1, characterized by, The bottom outlet of the hydrogen chloride gas washing tower (1) is connected with the separator (5) through a pipeline.

6. The dimethyldichlorosilane hydrolysis hydrogen chloride treatment apparatus for high-pressure chloromethane synthesis according to claim 1, characterized by, The top of the purification tower (7) is connected with the purification tower demister (8), and the purification tower demister (8) is connected with the compressor buffer tank (9).

7. The dimethyldichlorosilane hydrolysis hydrogen chloride treatment apparatus for high-pressure chloromethane synthesis according to claim 6, characterized by, The demister (4) is connected with the purification tower demister (8) through a pipeline, and the purification tower demister (8) is connected with the compressor buffer tank (9).

8. The dimethyldichlorosilane hydrolysis hydrogen chloride treatment apparatus for high-pressure chloromethane synthesis according to claim 7, characterized by, The bottom outlets of the purification tower (7) and the purification tower demister (8) are connected with a circulating pump through pipelines and then connected to the purification tower circulating cooler (12) and the dilute sulfuric acid storage area respectively, and the purification tower circulating cooler (12) is connected with the middle inlet of the purification tower (7).

9. The dimethyldichlorosilane hydrolysis hydrogen chloride treatment apparatus for high-pressure chloromethane synthesis according to claim 7, characterized by, The bottom outlet of the compressor buffer tank (9) is connected with the liquid discharge pipe (10), and the liquid discharge pipe (10) is connected to the storage tank area through the compressor buffer tank liquid discharge pump.

10. The dimethyldichlorosilane hydrolysis hydrogen chloride treatment apparatus for high-pressure chloromethane synthesis according to claim 1, characterized by, The purification tower (7) is provided with a concentrated sulfuric acid inlet pipeline.

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