阅读说明：本技术 带压氯化氢合成氯甲烷的工艺 (Process for synthesizing chloromethane from hydrogen chloride under pressure ) 是由 李书兵 高英 于 2018-06-28 设计创作，主要内容包括：本发明公开了一种带压氯化氢合成氯甲烷的工艺。将甲基氯硅烷水解得到的带压氯化氢气体经氯化氢的饱和氯化氢-甲醇溶液洗涤、活性炭纤维吸附联合处理技术除去其中的含硅化合物。纯化后的氯化氢气体与预热过的甲醇液体通过石墨喷射器送入氯甲烷合成釜合成氯甲烷。合成产物经除雾器后进入冷却器,冷却后的气液混合物全部进入氯甲烷水洗系统。本发明降低了甲基氯硅烷水解氯化氢中杂质对氯甲烷合成的不利影响,充分利用了合成反应热,精简了工艺,提高了氯甲烷合成釜时空产率和氯甲烷收率,减少废酸量,节能降耗,有显著的经济效益和环保效益。(The invention discloses a process for synthesizing methyl chloride by using hydrogen chloride under pressure. The pressurized hydrogen chloride gas obtained by hydrolyzing the methyl chlorosilane is washed by a saturated hydrogen chloride-methanol solution of hydrogen chloride and removed of silicon-containing compounds by an activated carbon fiber adsorption combined treatment technology. And (3) feeding the purified hydrogen chloride gas and preheated methanol liquid into a methyl chloride synthesis kettle through a graphite ejector to synthesize methyl chloride. The synthetic product enters a cooler after passing through a demister, and the cooled gas-liquid mixture completely enters a chloromethane washing system. The method reduces the adverse effect of impurities in the hydrogen chloride hydrolyzed by methyl chlorosilane on chloromethane synthesis, fully utilizes the synthesis reaction heat, simplifies the process, improves the space-time yield and the chloromethane yield of a chloromethane synthesis kettle, reduces the amount of waste acid, saves energy, reduces consumption, and has obvious economic benefit and environmental protection benefit.)

1. The process for synthesizing methyl chloride by using hydrogen chloride under pressure is characterized by comprising the following steps:

(1) spraying methanol from the upper part of the absorption tower, closing a feed valve when the liquid level reaches 40-60%, and starting a circulating pump of the absorption tower to circularly pump the methanol in the tower kettle into the upper part of the absorption tower;

(2) hydrogen chloride gas from the methyl chlorosilane hydrolysis procedure enters the lower part of an absorption tower through a pipeline, the pressure of the hydrogen chloride gas is 0.15-0.3MPa (G), methanol absorbs the hydrogen chloride gas to obtain a methanol-hydrogen chloride saturated solution, then the methanol is extracted, meanwhile, the methanol is supplemented, and the outside of the absorption tower adopts 3-8 ℃ chilled water for heat exchange until the temperature in a tower kettle is 20-35 ℃; the circulation amount of the methanol is 1 to 5 percent of the feeding volume of the hydrogen chloride, so that the solubility of the hydrogen chloride in the saturated methanol-hydrogen chloride solution is controlled to be 40 to 50g/100g of methanol; the mass ratio of the methanol addition amount to the methanol-hydrogen chloride extraction amount is 1: 1.5-2;

(3) and (3) mixing the preheated methanol with hydrogen chloride gas which is not absorbed in the step (2) in a graphite ejector, then feeding the mixture into a synthesis kettle, reacting the mixture under the action of a catalyst to generate methyl chloride, demisting, cooling to 80-100 ℃, feeding the mixture into a methyl chloride washing tower and a post-purification system, and thus completing the process for synthesizing methyl chloride by hydrolyzing hydrogen chloride with methyl chlorosilane.

2. The process for synthesizing chloromethane from hydrogen chloride under pressure as set forth in claim 1, wherein the hydrogen chloride gas in step (2) contains low molecular siloxane, organochlorosilane, water, and has a total impurity content of 2000-3000 ppm.

3. The process for the synthesis of methyl chloride from hydrogen chloride under pressure as claimed in claim 1, wherein in step (3), the methanol is preheated to 40-60 ℃ by a preheater; and (3) absorbing the hydrogen chloride gas which is not absorbed in the step (2) by an activated carbon fiber absorber before entering the graphite ejector, wherein the content of the organic silicon compound is less than 20 ppm.

4. The process for synthesizing methyl chloride from hydrogen chloride under pressure as claimed in claim 1, wherein the molar ratio of methanol to hydrogen chloride in the step (3) is 1: 0.95-1.019; the catalyst is zinc chloride, and the mass concentration of the zinc chloride is 70-80%.

5. The process for synthesizing chloromethane with pressurized hydrogen chloride as claimed in claim 1, wherein the temperature in the synthesis kettle in step (3) is controlled to be 135-155 ℃, and the pressure in the synthesis kettle is controlled to be 0.13-0.25 MPa; in the reaction process, a gas-phase reaction area and a bubbling reaction area are formed in the synthesis kettle, wherein the height ratio of the gas-phase reaction area to the bubbling reaction area is 1: 1-1.05.

Technical Field

The invention belongs to the technical field of methyl chloride synthesis, and particularly relates to a process and a device for synthesizing methyl chloride by hydrolyzing hydrogen chloride with methyl chlorosilane.

Background

Methyl chloride has three industrial production methods, namely a byproduct recovery method, a methane chlorination method and a methanol hydrochlorination method. A large amount of chloromethane is produced as a byproduct in the production process of glyphosate and the like, and the chloromethane as the byproduct contains more impurities. The methane chlorination process is a process in which methane and chlorine are chlorinated at a high temperature of 400 ℃ to produce methyl chloride and polychloride, and the single methyl chloride production is not generally used. The methanol chlorination process mixes hydrogen chloride and methanol in proportion, and synthesizes methyl chloride under certain temperature and pressure, wherein the method is divided into a gas-phase catalytic method, a liquid-phase catalytic method and a liquid-phase non-catalytic method. The catalyst of the gas phase catalysis method is active alumina, the catalyst of the liquid phase catalysis method is zinc chloride solution, and the catalyst is not used in the liquid phase non-catalysis method. One of main raw materials for producing the organic silicon monomer is chloromethane, and the sources of the raw materials are two, wherein one is to recycle and purify chloromethane which is a byproduct of glyphosate, and the other is to synthesize chloromethane, and more is to synthesize the glyphosate by a methanol hydrochlorination method. One of raw materials for synthesizing the chloromethane by adopting a methanol hydrochlorination method has two sources, namely hydrochloric acid is desorbed to obtain hydrogen chloride gas, and the hydrogen chloride gas under pressure is obtained by hydrolyzing dimethyldichlorosilane. The organic silicon enterprises adopt the production process suitable for the enterprises according to the self devices. When the hydrogen chloride hydrolyzed by the dimethyl dichlorosilane is used as a raw material, silane carried by the hydrogen chloride can be crosslinked under the catalytic condition, and a generated structural body blocks pipelines and equipment, so that the device cannot be continuously operated for a long time, for example, the capacity of a methyl chloride synthesizer is reduced, the reaction efficiency is reduced, the catalyst is forced to be replaced, the effect of a graphite cooler is poor, a heat exchange tube is blocked, a washing tower is filled with a filler, and the like.

The reaction principle of the methanol hydrochlorination method is as follows: CH (CH)₃OH+HCl=CH₃Cl+H₂O

The side reaction is: 2CH₃OH=（CH₃）₂O+ H₂O

The first reaction step: 2CH₃OH=（CH₃）₂O+ H₂O

And a second reaction step: (CH)₃）₂O+2 HCl=2 CH₃Cl+ 2H₂O

The hydrogen chloride and the methanol are subjected to dehydration esterification exothermic reaction under the catalysis of zinc chloride, and the reaction heat is 30.8kj/gmol chloromethane (298.15 k). The reaction is reversible, increasing the concentration of the reactants, and the heat of reaction vaporizes to remove the reaction products and water, allowing the reaction to proceed to the right. In order to maintain the reaction temperature, the conventional production method is to arrange a jacket outside the reactor, introduce circulating water into the jacket for cooling, or arrange a heating cooler outside the reactor for extracorporeal circulation to control the reaction temperature, or condense the synthesis gas, and return the condensate to the synthesis kettle for cooling, so that a certain amount of heat is lost through a heat exchange mode, the reaction heat cannot be fully utilized, and the required process equipment is complex. The catalytic synthesis method adopts excessive hydrogen chloride to inhibit the selectivity of dimethyl ether because the selectivity of dimethyl ether is increased along with the partial pressure of methanol in a reaction system, but generates a large amount of dilute hydrochloric acid containing alcohol.

Chinese patent CN1515528A discloses a pressurized synthesis and refining process of methane chloride, which comprises the steps of synthesizing methane chloride by a liquid phase catalysis method in which methanol and hydrogen chloride are proportionally mixed in a kettle-type reactor filled with a catalyst at 140 ℃ and 0.05-0.25MPa, washing with concentrated sulfuric acid to remove residual water and dimethyl ether as a reaction byproduct, and compressing and condensing the purified and dried methane chloride gas to obtain a high-purity methane chloride product. The methanol and the hydrogen chloride are separately fed after being vaporized, and the phenomena of shock cooling and shock heating of the reaction kettle are avoided through the extracorporeal circulation of the materials, so that the service life of the reaction kettle is prolonged. However, in the invention, the reaction liquid is required to be removed or supplemented with heat through a heat exchanger outside the kettle by a circulating pump, part of water and methanol which are condensed by a condenser are added into a gas-liquid separator, and the reactant which is discharged from the synthesis kettle flows back to the reaction kettle from the separator to adjust the temperature of the reaction kettle, so that more process flows and equipment are needed, the operation is complex, and the operation parameters in the kettle are easy to fluctuate. The gas phase methanol and the hydrogen chloride are fed separately, and the two raw materials are difficult to be mixed uniformly in the synthesis kettle, so that the reaction efficiency is influenced.

Chinese patent CN101429093A discloses an energy-saving production process for preparing methane chloride by a liquid phase catalysis method, wherein zinc chloride solution is used as a catalyst, and methane chloride and methanol are reacted in a reactor. Wherein, the gas-phase hydrogen chloride or the gas-phase hydrogen chloride is mixed with part of the gas-phase methanol gasified by the methanol vaporizer and enters the reactor, part or all of the methanol directly enters the reactor in a liquid-phase state to participate in the reaction, the liquid-phase methanol is introduced when the temperature in the reactor is 150-. The invention saves the consumption of pump electric energy and circulating water without circulating temperature reduction outside the kettle, and has obvious energy-saving effect. On the basis of the existing technology for preparing methyl chloride by a liquid phase method, the whole gas phase feeding mode is changed into partial liquid phase feeding, and the reaction temperature is controlled by liquid phase methanol, so that the phenomenon of quenching and shock heating generated by a reactor can be avoided. However, the methanol liquid is independently fed in one way, which inevitably causes uneven contact with hydrogen chloride in the reactor, complicated structure in the reactor or the need of a stirring device to achieve the mixing effect. The reactants pass through a gas-liquid separation tank, so that partial reaction products are condensed, and the liquid phase flows back to the reactor, so that partial reaction products enter a synthesis kettle, and the positive reaction is inhibited. The reaction product 150-. Liquid methanol can be introduced only when the synthesis kettle reaches a certain temperature, which causes unnecessary energy consumption, or causes system instability due to frequent switching, and the like.

Chinese patent CN102153439A discloses a process for producing high-purity methane chloride, wherein methanol and hydrogen chloride are gasified and then enter a reactor filled with an alumina catalyst, and a mixture of methane chloride, methane, ethyl chloride and dichloromethane is generated in the reactor; the generated mixture enters a chiller, is chilled to 50-100 ℃ by dilute hydrochloric acid, is separated and then enters an acid washing tower, an alkali washing tower and a sulfuric acid drying system, and is compressed to prepare crude methane chloride; and (3) the crude methane chloride enters a methane chloride refining tower to be separated to obtain refined methane chloride. The process can prepare methane chloride with content over 99.98%. However, the reaction temperature and pressure are high, the requirements on equipment are high, reaction byproducts are more, and the product needs to be further refined by a rectifying tower.

Chinese patent CN106008151A discloses a synthesis method of methyl chloride. Hydrochloric acid and methanol are directly mixed, and methyl chloride is directly synthesized in a reaction solution consisting of methanol, hydrogen chloride and water. And (3) the reactant enters a rectifying tower, and the methyl chloride at the top of the rectifying tower is dried by sulfuric acid to obtain a methyl chloride product. Wherein the molar ratio of methanol to chloride is 1-1.7: 1, the mixture reacts under the conditions of 0.15-1.0MPa and 100-150 ℃ without catalyst. The method utilizes 10-40% hydrochloric acid as a raw material, reduces the technical process of desorbing hydrogen chloride gas by hydrochloric acid, but a large amount of water contained in the hydrochloric acid needs more heat to evaporate the water, reduces the contact probability of methanol and hydrogen chloride, and has low reaction efficiency and high energy consumption. Excessive methanol, more side reaction product dimethyl ether and large consumption of subsequent sulfuric acid. The heating system outside the reactor has complex process.

Disclosure of Invention

The invention develops a process for synthesizing chloromethane by using pressurized hydrogen chloride hydrolyzed by methyl chlorosilane aiming at the technical problems, which comprises the following specific steps:

and pumping the methanol in the methanol storage tank into the tower bottom of the absorption tower to 40-60% of the liquid level by a methanol feeding pump, and closing a feeding valve. Starting the circulating pump of the absorption tower to circularly pump the methanol in the tower bottom into the top of the absorption tower. Pressurized hydrogen chloride gas is self-methyl

The chlorosilane hydrolysis procedure enters the bottom of the absorption tower through a pipeline, and methanol absorbs hydrogen chloride gas to gradually form methanol-hydrogen chloride saturated solution. The hydrogen chloride gas from the top of the absorption tower is absorbed by the activated carbon fiber absorber to obtain the residual organic silicon compound, and the liquid phase at the bottom of the activated carbon fiber absorber automatically flows into the liquid phase area of the absorption tower kettle. The methanol is sent into a methanol preheater by a methanol feeding pump to be preheated to 40-60 ℃ and the molar ratio of hydrogen chloride gas from the activated carbon fiber absorber is as follows: methanol = 0.95-1.019: 1, mixing the mixture by a graphite ejector, entering a gas-liquid distributor of a synthesis kettle, and reacting in a catalyst solution to generate methyl chloride. The synthesized mixture enters a methyl chloride cooler after passing through a demister at the upper part of a synthesis kettle, the synthesized mixture is cooled to 70-100 ℃ by adopting hot water at 50-70 ℃, and then enters a methyl chloride washing tower, the concentration of the alcohol-containing olefine acid obtained from the kettle of the washing tower is 15-20%, and the content of methanol is less than or equal to 2%. And the methyl chloride enters the post-purification system from the top of the water washing tower.

The pressure of hydrogen chloride gas from the methyl chlorosilane hydrolysis procedure is 0.15-0.3MPa (G), and the hydrogen chloride contains low molecular siloxane, organic chlorosilane and water, and the total content of impurities is 2000-3000 ppm.

The absorption tower is provided with a heat exchanger in an external circulation way, the heat exchange is carried out by adopting chilled water with the temperature of 3-8 ℃, and the temperature of the washing tower is controlled to be 20-35 ℃. The methanol circulation amount is 1-5% of the hydrogen chloride feeding volume. The hydrogen chloride solubility in the saturated methanol-hydrogen chloride solution is 40-50g/100g methanol.

A fresh methanol replenishing pipeline is arranged at the top of the absorption tower, a methanol-hydrogen chloride solution extraction pipeline is arranged behind a circulating pump of the absorption tower, methanol is replenished intermittently, and the methanol-hydrogen chloride solution is extracted intermittently. The mass ratio of the methanol addition amount to the methanol-hydrogen chloride extraction amount is 1: 1.5-2.

After the hydrogen chloride gas passes through the activated carbon fiber absorber, the bottom liquid phase automatically flows into the bottom of the absorption tower, a communicating pipe from the bottom of the activated carbon fiber absorber to the washing tower is provided with a water seal of 0.5-1m to avoid gas phase reverse connection, and a pipeline sight glass is arranged to observe whether the liquid flow is smooth. The content of organosilicon compounds in the hydrogen chloride gas after passing through the activated carbon fiber absorber is less than 20 ppm.

The temperature of the chloromethane synthesis kettle is 135-. 70-80wt%, preferably 75wt% of zinc chloride solution is filled in the synthesis kettle as a catalyst, the catalyst is heated to the reaction temperature by an external circulation heating system at the initial start-up stage, the heating is stopped, and then a gas-liquid mixture consisting of hydrogen chloride and methanol enters a reactor to generate an exothermic reaction. The height ratio of the gas phase reaction zone to the bubbling reaction zone is 1:1-1.05, and the height of the bubbling reaction zone is 2-3 m. Sufficient reaction space and time are provided for the methanol and the hydrogen chloride.

According to the above process steps, the technical scheme of the invention also provides a device for synthesizing methyl chloride by hydrolyzing hydrogen chloride with methyl chlorosilane. Specifically, a methanol tank is respectively connected with the upper part of an absorption tower and a methanol preheater, and hydrogen chloride hydrolyzed by methyl chlorosilane is connected with the lower part of the absorption tower;

the methanol preheater is converged and connected with the top of the absorption tower through a pipeline and a graphite ejector;

the graphite injector is connected with the synthesis kettle, the synthesis kettle is connected with the methyl chloride cooler at the top and then connected with the water washing tower, and the top of the water washing tower is connected with the methyl chloride purification system.

The bottom of the absorption tower is connected with a cooler through a circulating pump, and the cooler is connected to the upper part of the absorption tower.

The top of the absorption tower is connected with an activated carbon fiber absorber and then connected with a graphite ejector; the bottom of the activated carbon fiber absorber is connected with the lower part of the absorption tower through a pipeline.

The methanol preheater is connected with the methyl chloride cooler through a pipeline, and the methyl chloride cooler is connected with the methanol preheater through a pipeline to form a circulation loop.

The invention has the following characteristics:

1. methyl chlorosilane is adopted to hydrolyze hydrogen chloride gas with pressure to synthesize methyl chloride, raw materials are easy to obtain, and a hydrochloric acid desorption process and additional pressurization and conveying of hydrogen chloride are not needed.

2. Methanol is adopted to absorb silicon-containing compounds and other organic impurities in hydrogen chloride, and the methanol and the silicon-containing compounds with chlorine can be hydrolyzed to generate silanol compounds. The methanol can absorb and dissolve organic compounds, and does not bring new impurities to the synthesis of the methyl chloride. The impurities in the chloromethane can be reduced to 20ppm, the synthesis reaction efficiency of the chloromethane is improved, and the blockage probability of equipment and pipelines is reduced.

3. The catalyst in the synthesis kettle is heated to the reaction temperature by adopting an external circulation heat mode, and then a gas-liquid mixture of hydrogen chloride and methanol is introduced. The liquid-phase methanol is vaporized in the reaction kettle, and the heat generated by the reaction is absorbed at the same time, so that the temperature of the reflux liquid is not required to be reduced, thereby saving the consumption of circulating water for reducing the temperature of the reactor or the power consumption of electromechanical equipment for extracorporeal circulation and achieving the purpose of energy conservation. According to the reaction mechanism, the product is timely removed, the forward and reverse speed and the methyl chloride conversion rate are favorably improved, and the content of the byproduct dimethyl ether is lower. Generally, the methyl chloride conversion rate of the synthesis process of hydrolyzing hydrogen chloride by utilizing methyl chlorosilane is 99.5 percent, and the methyl chloride conversion rate of the process reaches more than 99.8 percent.

4. According to the reaction kinetics relation of hydrogen chloride and methanol, the proportion of the methanol and the hydrogen chloride is close to a theoretical value, sufficient gas-liquid contact time and space are provided, reverse reaction factors are eliminated in time, the conversion rate of the methanol is high, and the obtained waste hydrochloric acid is less. The common process can averagely produce 0.75t of dilute hydrochloric acid containing methanol every 1t of methyl chloride synthesized, the dilute hydrochloric acid contains about 5 percent of methanol, while the process can averagely produce 0.35t of dilute acid containing alcohol every 1t of methyl chloride synthesized, wherein the content of the methanol is less than 2 percent.

5. The synthesized mixture (containing methanol, hydrogen chloride, dimethyl ether, water and chloromethane) is initially cooled to 80-100 ℃, and the condensed gas-liquid mixture is sent to a water washing tower, so that the problem that the temperature difference of the water washing tower is large, the requirement on the material of the water washing tower is reduced, and the service life of the water washing tower is prolonged.

6. The reactor controls a certain gas phase reaction zone and is provided with a demister at an outlet to eliminate entrainment, so that the catalyst is intercepted to the reaction kettle, the catalyst loss is reduced, and reactants are prevented from being condensed and mixed into the reaction kettle.

Drawings

FIG. 1 is a process flow diagram of the present invention, wherein: 1. an absorption tower; 2. a circulating pump of the absorption tower; 3. an absorber tower cooler; 4. an activated carbon fiber absorber; 5. a methanol tank; 6 methanol feed pump; 7. a graphite injector; 8. a synthesis kettle; 9. a demister; 10. a methyl chloride cooler; 11. washing the tower with water; 12. a methanol preheater; 13. a pipeline sight glass.

The specific implementation mode is as follows:

example 1

A device for synthesizing chloromethane by hydrolyzing hydrogen chloride with methyl chlorosilane is characterized in that a methanol tank is respectively connected with the upper part of an absorption tower and a methanol preheater, and the hydrogen chloride hydrolyzed with the methyl chlorosilane is connected with the lower part of the absorption tower;

the methanol preheater is converged and connected with the top of the absorption tower through a pipeline and a graphite ejector;

the graphite injector is connected with the synthesis kettle, the synthesis kettle is connected with the methyl chloride cooler at the top and then connected with the water washing tower, and the top of the water washing tower is connected with the methyl chloride purification system.

The bottom of the absorption tower is connected with a cooler through a circulating pump, and the cooler is connected to the upper part of the absorption tower.

The top of the absorption tower is connected with an activated carbon fiber absorber and then connected with a graphite ejector; the bottom of the activated carbon fiber absorber is connected with the lower part of the absorption tower through a pipeline.

The methanol preheater is connected with the methyl chloride cooler through a pipeline, and the methyl chloride cooler is connected with the methanol preheater through a pipeline to form a circulation loop.

Example 2

75 percent of zinc chloride solution in the synthesis kettle is heated to 135-140 ℃ for standby through an external circulation system. The methanol feeding pump 6 pumps the methanol in the methanol storage tank 5 into the absorption tower 1 until the liquid level of the tower kettle reaches 60%, and the feeding valve is closed. Starting an absorption tower circulating pump 2, circularly pumping methanol at the tower bottom into the top of the absorption tower through an absorption tower cooler 3, introducing 2000ppm of impurities in hydrogen chloride gas with the pressure of 0.15MPa (G) in a methyl chlorosilane hydrolysis procedure into the bottom of the absorption tower 1 through a pipeline, gradually forming hydrogen chloride-methanol saturated solution by absorbing the hydrogen chloride gas with the methanol, introducing frozen saline water into the methanol absorption tower cooler 3, controlling the temperature of the absorption tower 1 to be 20 ℃, controlling the solubility of the hydrogen chloride in the methanol to be 40%, and controlling the volume of circulating liquid in the absorption tower 1 to be 1% of the feeding volume of the hydrogen chloride. The hydrogen chloride gas from the top of the absorption tower 1 is absorbed by the activated carbon fiber absorber 4 to obtain the residual silicon-containing compound, the impurity content in the hydrogen chloride gas is 10pmm, and the liquid phase at the bottom of the activated carbon absorber automatically flows into the liquid phase area of the tower kettle of the absorption tower 1. The methanol feed pump 6 sends the methanol into a methanol preheater 12 to be preheated to 40-50 ℃, and the molar ratio of the methanol to the hydrogen chloride gas from the activated carbon fiber absorber 4 is as follows: methanol = 0.99: 1 is mixed by a graphite ejector 7 and enters a gas-liquid distributor of a synthesis kettle 8, and the methyl chloride is generated by catalytic reaction. The height ratio of the gas phase reaction zone and the bubbling reaction zone of the synthesis kettle 8 is 1:1, the height of the bubbling reaction zone is 2m, the reaction temperature is 135 ℃, and the pressure is 0.13 MPa (G). Removing catalyst and other foams from the reaction mixture by a demister 9 at the upper part of a synthesis kettle 8, feeding the reaction mixture into a methyl chloride cooler 10, cooling the synthesized mixture to 70-75 ℃ by adopting hot water at 50 ℃, feeding the cooled mixture into a methyl chloride water washing tower 11, and feeding the mixture into a post-purification system from the top of the water washing tower 11 to obtain 0.4t of alcohol-containing olefine acid with the concentration of 15 wt% when 1 ton of methyl chloride is synthesized, wherein the content of methanol is 1.5%, and the conversion rate of the methyl chloride is 99.9%. Methanol is added into the absorption tower 1 intermittently in the production process, and the hydrogen chloride-methanol solution in the tower kettle is extracted intermittently. The mass ratio of the methanol addition amount to the methanol-hydrogen chloride extraction amount is 1: 1.5.

Example 3

75 percent of zinc chloride solution in the synthesis kettle is heated to 140-145 ℃ for standby through an external circulation system. The methanol feeding pump 6 pumps the methanol in the methanol storage tank 5 into the absorption tower 1 until the liquid level of the tower kettle reaches 40%, and the feeding valve is closed. Starting an absorption tower circulating pump 2, circularly pumping methanol at the tower bottom into the top of an absorption tower through an absorption tower cooler 3, introducing 3000ppm of impurities in hydrogen chloride gas with the pressure of 0.3MPa (G) in a methyl chlorosilane hydrolysis procedure into the bottom of the absorption tower 1 through a pipeline, gradually forming hydrogen chloride-methanol saturated solution by absorbing the hydrogen chloride gas with the methanol, introducing frozen saline water into the methanol absorption tower cooler 3, controlling the temperature of the absorption tower 1 to be 35 ℃, controlling the solubility of the hydrogen chloride in the methanol to be 50%, and controlling the volume of circulating liquid in the absorption tower 1 to be 5% of the feeding volume of the hydrogen chloride. The hydrogen chloride gas from the top of the absorption tower 1 is absorbed by the activated carbon fiber absorber 4 to obtain the residual silicon-containing compound, the impurity content in the hydrogen chloride gas is 15pmm, and the liquid phase at the bottom of the activated carbon absorber automatically flows into the liquid phase area of the tower kettle of the absorption tower 1. The methanol feed pump 6 sends the methanol into a methanol preheater 12 to be preheated to 50-60 ℃, and the molar ratio of the methanol to the hydrogen chloride gas from the activated carbon fiber absorber 4 is as follows: methanol = 1:1 is mixed by a graphite ejector 7 and enters a gas-liquid distributor of a synthesis kettle 8, and the methyl chloride is generated by catalytic reaction. The height ratio of the gas phase reaction zone to the bubbling reaction zone of the synthesis kettle 8 is 1:1.05, the height of the bubbling reaction zone is 3m, the reaction temperature is 155 ℃, and the pressure is 0.25MPa (G). Removing catalyst and other foams from the reaction mixture by a demister 9 at the upper part of a synthesis kettle 8, feeding the reaction mixture into a methyl chloride cooler 10, cooling the synthesized mixture to 100 ℃ by adopting hot water at 60-70 ℃, feeding the synthesized mixture into a methyl chloride water washing tower 11, wherein when 1 ton of methyl chloride is synthesized, the content of methanol in the 16 wt% alcohol-containing olefine acid obtained from the kettle of the water washing tower 11 is 2%, and the methyl chloride enters a post-purification system from the top of the water washing tower, so that the conversion rate of the methyl chloride is 99.9%. Methanol is added into the absorption tower 1 intermittently in the production process, and the hydrogen chloride-methanol solution in the tower kettle is extracted intermittently. The mass ratio of the methanol addition amount to the methanol-hydrogen chloride extraction amount is 1: 2.

Example 4

75 percent of zinc chloride solution in the synthesis kettle is heated to 145-150 ℃ for standby through an external circulation system. The methanol feeding pump 6 pumps the methanol in the methanol storage tank 5 into the absorption tower 1 until the liquid level of the tower kettle reaches 60%, and the feeding valve is closed. Starting an absorption tower circulating pump 2, circularly pumping methanol at the tower bottom into the top of the absorption tower through an absorption tower cooler 3, introducing 2500ppm of impurities in hydrogen chloride gas with the pressure of 0.18MPa (G) in a methyl chlorosilane hydrolysis procedure into the bottom of the absorption tower 1 through a pipeline, gradually forming hydrogen chloride-methanol saturated solution by absorbing the hydrogen chloride gas with the methanol, introducing frozen saline water into the methanol absorption tower cooler 3, controlling the temperature of the absorption tower 1 to be 35 ℃, controlling the solubility of the hydrogen chloride in the methanol to be 40%, and controlling the volume of circulating liquid in the absorption tower 1 to be 3% of the feeding volume of the hydrogen chloride. The hydrogen chloride gas from the top of the absorption tower 1 is absorbed by the activated carbon fiber absorber 4 to obtain the residual silicon-containing compound, the impurity content in the hydrogen chloride gas is 20pmm, and the liquid phase at the bottom of the activated carbon absorber automatically flows into the liquid phase area of the tower kettle of the absorption tower 1. The methanol feed pump 6 sends the methanol into a methanol preheater 12 to be preheated to 55-60 ℃, and the molar ratio of the methanol to the hydrogen chloride gas from the activated carbon fiber absorber 4 is as follows: methanol = 0.95: 1 is mixed by a graphite ejector 7 and enters a gas-liquid distributor of a synthesis kettle 8, and the methyl chloride is generated by catalytic reaction. The height ratio of the gas phase reaction zone to the bubbling reaction zone of the synthesis kettle 8 is 1:1.05, the height of the bubbling reaction zone is 3m, the reaction temperature is 140 ℃, and the pressure is 0.15MPa (G). Removing catalyst and other foams from the reaction mixture by a demister 9 at the upper part of a synthesis kettle 8, feeding the reaction mixture into a methyl chloride cooler 10, cooling the synthesized mixture to 100 ℃ by adopting hot water at 65-70 ℃, feeding the cooled mixture into a methyl chloride water washing tower 11, synthesizing one ton of methyl chloride, and obtaining 0.3t of 17 wt% alcohol-containing olefine acid by the tower kettle of the water washing tower 11, wherein the content of methanol is 1.5%, and the methyl chloride enters a post-purification system from the top of the water washing tower, and the conversion rate of the methyl chloride is 99.8%. Methanol is added into the absorption tower 1 intermittently in the production process, and the hydrogen chloride-methanol solution in the tower kettle is extracted intermittently. The mass ratio of the methanol addition amount to the methanol-hydrogen chloride extraction amount is 1: 2.

Example 5

75 percent of zinc chloride solution in the synthesis kettle is heated to 150 ℃ and 160 ℃ for standby through an external circulation system. The methanol feeding pump 6 pumps the methanol in the methanol storage tank 5 into the absorption tower 1 until the liquid level of the tower kettle reaches 50%, and the feeding valve is closed. Starting an absorption tower circulating pump 2, circularly pumping methanol at the tower bottom into the top of the absorption tower through an absorption tower cooler 3, introducing 2500ppm of impurities in hydrogen chloride gas with the pressure of 0.2MPa (G) in a methyl chlorosilane hydrolysis procedure into the bottom of the absorption tower 1 through a pipeline, gradually forming hydrogen chloride-methanol saturated solution by absorbing the hydrogen chloride gas with the methanol, introducing frozen saline water into the methanol absorption tower cooler 3, controlling the temperature of the absorption tower 1 to be 20 ℃, controlling the solubility of the hydrogen chloride in the methanol to be 50%, and controlling the volume of circulating liquid in the absorption tower 1 to be 2% of the feeding volume of the hydrogen chloride. The hydrogen chloride gas from the top of the absorption tower 1 is absorbed by the activated carbon fiber absorber 4 to obtain the residual silicon-containing compound, the impurity content in the hydrogen chloride gas is 15pmm, and the liquid phase at the bottom of the activated carbon absorber automatically flows into the liquid phase area of the tower kettle of the absorption tower 1. The methanol feed pump 6 sends the methanol into a methanol preheater 12 to be preheated to 45-55 ℃, and the molar ratio of the methanol to the hydrogen chloride gas from the activated carbon fiber absorber 4 is as follows: methanol = 1.019: 1 is mixed by a graphite ejector 7 and enters a gas-liquid distributor of a synthesis kettle 8, and the methyl chloride is generated by catalytic reaction. The height ratio of the gas phase reaction zone to the bubbling reaction zone of the synthesis kettle 8 is 1:1.05, the height of the bubbling reaction zone is 2.5m, the reaction temperature is 145 ℃, and the pressure is 0.18MPa (G). The reaction mixture is removed catalyst and other mist through a demister 9 at the upper part of a synthesis kettle 8 and enters a methyl chloride cooler 10, the synthesized mixture is cooled to 95 ℃ by adopting hot water at 70 ℃ and enters a methyl chloride water washing tower 11, the concentration of 15 wt% alcohol-containing olefine acid obtained by synthesizing one ton of methyl chloride at the tower bottom of the water washing tower 11 is 0.3t, wherein the content of methanol is 2%, the methyl chloride enters a post-purification system from the top of the water washing tower, and the conversion rate of the methyl chloride is 99.8%. Methanol is added into the absorption tower 1 intermittently in the production process, and the hydrogen chloride-methanol solution in the tower kettle is extracted intermittently. The mass ratio of the methanol addition amount to the methanol-hydrogen chloride extraction amount is 1: 2.