Methyl chloride purification device

Abstract

The utility model relates to a methane chloride purification device which comprises a combined water washing tower and a combined sulfuric acid washing purification tower which are sequentially communicated, a water washing filler area and a water washing tower plate area are arranged in the combined water washing tower from bottom to top, and a purification filler area and a purification tower plate area are arranged in the sulfuric acid washing purification tower from bottom to top; the water washing tower plate area is communicated with a primary water inlet pipeline, and the purification tower plate area is communicated with a concentrated sulfuric acid inlet pipe. According to the utility model, a five-stage tower device is optimized into a two-stage tower device, so that the number of equipment and pipelines is reduced, the cooling capacity damage is reduced, and the energy consumption is reduced; an alkaline washing tower is omitted, so that the discharge of waste brine is reduced; according to the utility model, the combined tower is applied to the purification process of methane chloride, the original multi-stage filler circulation step-by-step absorption is replaced, and on the premise of meeting the technological requirements of the device, the tower plates are arranged to replace the filler, the low liquid phase flow replaces the high liquid phase flow, the liquid phase circulation in the system is reduced, and the energy consumption is reduced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the one chloromethane post -treatment technical field, specifically speaking is related to a one chloromethane purification device. BACKGROUND

[0002] Chloromethane (monochloromethane) synthesis process is generally by two kinds of production technology, one is with zinc chloride aqueous solution as catalyst high temperature reaction synthesis, one is solid phase catalyst high temperature reaction synthesis, each has the advantages and disadvantages.

[0003] In the production of organosilicon, hydrogen chloride is derived from methyl chlorosilane hydrolysis by-product, and hydrogen chloride contains a certain amount of siloxane. Therefore, chloromethane, as the raw material for synthesizing methyl chlorosilane in organosilicon, generally adopts wet synthesis technology.

[0004] Chloromethane synthesis process:

[0005]

[0006] Side reaction:

[0007]

[0008] The purification device involved in the monochloromethane post-treatment process generally adopts a five-tower device structure of water washing tower 1 + alkali washing tower 1 + sulfuric acid purification tower 3. The water washing function absorbs the acidic gas (such as HCl) and most of the methanol in the gas phase; the alkali washing function absorbs the trace amount of hydrogen chloride in the gas phase that has not been absorbed; and the sulfuric acid purification function absorbs the residual methanol, water, dimethyl ether produced by side reaction, and trace amount of siloxane in the gas phase. The existing technology involves using ordinary packing towers in the tower body, which washes the gas phase by large circulation to achieve the purpose of purification. However, there are the following shortcomings:

[0009] The water washing tower uses hydrochloric acid of the same concentration for circulation washing and absorption. Due to the relative volatility, hydrogen chloride cannot be completely dissolved in the liquid phase, resulting in an increase in alkali consumption in the subsequent alkali washing tower;

[0010] The alkali washing tower absorbs trace amount of hydrogen chloride in the gas phase using a packing tower for circulation absorption. The low amount of acidic substances in the gas phase leads to high energy consumption due to large circulation.

[0011] The sulfuric acid purification tower uses multi-stage washing. Although the concentration gradient is increased to promote absorption, the absorption effects of different towers are different. However, 90% or more of the impurities in the gas phase are purified in the first stage tower, and the subsequent tower purification is only for the remaining 10%. Moreover, the packing tower has poor purification effect for trace amount of impurities and large circulation, which increases the energy consumption of the system. UTILITY MODEL CONTENTS

[0012] In order to overcome the deficiencies in the prior art, the utility model provides a methyl chloride purification device, under the condition of satisfying methyl chloride index requirement, effectively reduce the operation cost and investment cost of methyl chloride purification device.

[0013] The utility model adopts the technical scheme as follows:

[0014] A methyl chloride purification device, the device includes combined water washing tower and combined sulfuric acid washing purification tower which are communicated in sequence, water washing filler area and water washing tray area are equipped in the combined water washing tower from bottom to top, purification filler area and purification tray area are equipped in the combined sulfuric acid washing purification tower from bottom to top, the water washing tray area is linked with primary water inlet pipeline, and the purification tray area is linked with concentrated sulfuric acid inlet pipe.

[0015] As preferred, the bottom of the combined water washing tower is provided with a first liquid outlet, the upper part of the combined water washing tower is provided with a first liquid return port, and the top of the combined water washing tower is provided with a first gas outlet, and the first liquid outlet is sequentially communicated with the first liquid return port on the combined water washing tower through a first circulating pump and a first cooler.

[0016] As preferred, the first gas outlet is communicated with a first demister.

[0017] As preferred, the first liquid return port is arranged between the water washing filler area and the water washing tray area.

[0018] As preferred, the bottom of the combined sulfuric acid washing purification tower is provided with a second liquid outlet, the upper part of the combined sulfuric acid washing purification tower is provided with a second liquid return port, and the top of the combined sulfuric acid washing purification tower is provided with a second gas outlet, and the second liquid outlet is sequentially communicated with the second liquid return port on the combined sulfuric acid washing purification tower through a second circulating pump and a second cooler.

[0019] As preferred, the second gas outlet is communicated with a second demister.

[0020] As preferred, the second liquid return port is arranged between the purification filler area and the purification tray area.

[0021] As preferred, an 80% sulfuric acid outlet is arranged on the pipeline between the second circulating pump and the second cooler.

[0022] As preferred, the first demister is communicated with the inlet of the lower part of the combined sulfuric acid washing purification tower.

[0023] As preferred, the number of the water washing filler area is more than one, and the number of the water washing tray area is more than one. When the number of the water washing filler area and the water washing tray area is one, the combined water washing tower is provided with one-stage filler and one-stage tray.

[0024] As preferred, the number of the purification packing zone is more than one, and the number of the purification tray zone is more than one. When the number of the purification packing zone and the purification tray zone is one, the combined sulfuric acid washing purification tower is provided with one stage of packing and one stage of tray.

[0025] The utility model discloses the beneficial effect lies in:

[0026] 1, with the combined water washing tower replacement water washing soda washing process, the hydrogen chloride is basically absorbed into the water phase, forms the valuable hydrochloric acid, reduces the sodium chloride waste salt solution because of soda washing, reduces the pollutant discharge, removes the setting of soda washing tower, reduces the energy consumption because of soda washing process.

[0027] 2, with the combined sulfuric acid washing purification tower replacement original multi -tower process, can satisfy the absorption requirement of original device under the condition that the circulating capacity is less.

[0028] 3, the original five stage tower absorption optimization is two -stage combined tower absorption, under the condition that the original process requirement is satisfied, the equipment land occupation is reduced, the number of circulating pump in system is reduced, and the energy consumption is reduced, and the device operation process is all under low temperature operation, reduces the equipment quantity and the pipe number, reduces the loss of cold, is an energy -conserving and consumption -reducing and green means of emission reduction. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is the structure diagram of the utility model. DETAILED DESCRIPTION

[0030] The utility model will be further described in connection with the drawings and specific embodiment, but the protection scope of the utility model is not limited to this.

[0031] Referring to Figure 1 A methyl chloride purification device, the device includes combined water washing tower 1 and combined sulfuric acid washing purification tower 2 communicated in sequence, the combined water washing tower is equipped with water washing packing zone 3 and water washing tray zone 4 from bottom to top, the sulfuric acid washing purification tower is equipped with purification packing zone 5 and purification tray zone 6 from bottom to top, the water washing tray zone is connected with primary water inlet pipeline 7, and the purification tray zone is connected with concentrated sulfuric acid inlet pipeline 8 with mass fraction of 95%.

[0032] The bottom of the combined water washing tower is equipped with first liquid outlet 9, the upper portion of the combined water washing tower is equipped with first liquid return port 10, and the top of the combined water washing tower is equipped with first gas outlet 11, the first liquid outlet 9 sequentially communicates with the first liquid return port 10 on the combined water washing tower through first circulating pump 12 and first cooler 13, and the first liquid return port 10 is arranged between the water washing packing zone 3 and the water washing tray zone 4.

[0033] The first gas outlet 11 is communicated with the first demister 14, and the first demister 14 is communicated with the inlet 15 of the lower part of the combined sulfuric acid washing and purifying tower.

[0034] The bottom of the combined sulfuric acid washing and purifying tower is provided with a second liquid outlet 16, the upper part of the combined sulfuric acid washing and purifying tower is provided with a second liquid return port 17, and the top of the combined sulfuric acid washing and purifying tower is provided with a second gas outlet 18; the second liquid outlet 16 is sequentially communicated with the second liquid return port 17 on the combined sulfuric acid washing and purifying tower through a second circulating pump 19 and a second cooler 20, and the second liquid return port 17 is arranged between the purification packing area 5 and the purification tower plate area 6; the second gas outlet 18 is communicated with a second demister 21, and the pipeline between the second circulating pump 19 and the second cooler 20 is provided with a 80% sulfuric acid outlet 22.

[0035] The combined water washing tower can set the water washing process as a combination of packing and tower plate according to different hydrogen chloride partial pressures (relative volatility) under different concentrations, the concentration of the packing layer is controlled to be below 20%, the tower plate layer uses primary water as an absorbent, the concentration of hydrochloric acid in different absorption sections in the tower is adjusted, hydrogen chloride in the gas phase can be completely absorbed as much as possible, according to absorption calculation, the hydrogen chloride partial pressure in the gas phase is reduced from the original 0.205mmhg to 0.000044mmhg, and the hydrogen chloride content in the gas phase is reduced from 170ppm to below 1ppm, so that the hydrogen chloride in the gas phase can be completely absorbed by using water directly, and it is not necessary to set an alkali washing tower for washing and absorption.

[0036] The combined sulfuric acid washing and purifying tower is set as a combination of packing and tower plate, the absorption is gradually performed through the packing and the tower plate, the concentration gradient is ensured by the setting of the tower plate due to low absorption component content and quantity, heat generated is low, and the liquid phase temperature on the tower plate is ensured when absorption is performed at a small flow rate; the combined sulfuric acid washing and purifying tower can improve the concentration gradient of absorption of the tower according to absorption requirements, and can meet the absorption requirements of the original device under a small circulation amount condition.

[0037] The utility model discloses simple structure, reasonable in design, optimize five stage tower to 2 stage tower, reduce the equipment and the pipe number, reduce the cold quantity damage, reduce the energy consumption, reduce the alkali washing tower, reduce the waste brine discharge, the utility model discloses combined tower is applied to methyl chloride purification process, replaces the original multistage packing circulation and gradually absorbs, under the premise of satisfying device process requirement, sets up tower plate and replaces packing, replaces high liquid phase flow at low liquid phase flow, reduces the liquid phase circulation in system, reduces the energy consumption.

[0038] The above embodiment is used to explain and illustrate the utility model, instead of limiting the utility model, and any modification and change of the utility model within the spirit and protection scope of the claims falls into the protection scope of the utility model.

Claims

1. A monochloromethane purification apparatus, characterized by: The device comprises a combined water washing tower and a combined sulfuric acid washing and purifying tower which are connected in sequence, the water washing tower is provided with a water washing filler area and a water washing tray area from bottom to top, the sulfuric acid washing and purifying tower is provided with a purifying filler area and a purifying tray area from bottom to top; the water washing tray area is connected with a primary water inlet pipeline, and the purifying tray area is connected with a 95% concentrated sulfuric acid inlet pipeline.

2. The methyl chloride purification apparatus according to claim 1, wherein: The bottom of the combined water washing tower is provided with a first liquid outlet, the upper part of the combined water washing tower is provided with a first liquid return port, and the top of the combined water washing tower is provided with a first gas outlet; the first liquid outlet is connected with the first liquid return port of the combined water washing tower in sequence through a first circulating pump and a first cooler.

3. The methyl chloride purification apparatus according to claim 2, wherein: The first gas outlet is connected with a first demister.

4. The methyl chloride purification apparatus according to claim 2, wherein: The first liquid return port is arranged between the water washing filler area and the water washing tray area.

5. The methyl chloride purification apparatus of claim 1, wherein: The bottom of the combined sulfuric acid washing and purifying tower is provided with a second liquid outlet, the upper part of the combined sulfuric acid washing and purifying tower is provided with a second liquid return port, and the top of the combined sulfuric acid washing and purifying tower is provided with a second gas outlet; the second liquid outlet is connected with the second liquid return port of the combined sulfuric acid washing and purifying tower in sequence through a second circulating pump and a second cooler.

6. The methyl chloride purification apparatus according to claim 5, wherein: The second gas outlet is connected with a second demister.

7. The methyl chloride purification apparatus according to claim 5, wherein: The second liquid return port is arranged between the purifying filler area and the purifying tray area.

8. The methyl chloride purification apparatus of claim 5, wherein: An 80% sulfuric acid outlet is arranged on a pipeline between the second circulating pump and the second cooler.

9. The methyl chloride removal device according to claim 3, wherein: The first demister is connected with an inlet of the lower part of the combined sulfuric acid washing and purifying tower.

10. The methyl chloride removal device of claim 1, wherein: The number of the water washing filler area is more than one, and the number of the water washing tray area is more than one; the number of the purifying filler area is more than one, and the number of the purifying tray area is more than one.

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