A vinyl chloride production apparatus and production method

Abstract

This invention discloses a vinyl chloride production apparatus and method. The vinyl chloride production apparatus includes a primary reaction tower, a secondary reaction tower, a heat exchanger, a circulating pump, and a catalyst storage tank. The bottom outlet of the catalyst storage tank is connected in series with the circulating pump and the heat exchanger via a pipeline, and then branched into two pipelines. One pipeline connects to the first inlet of the primary reaction tower, and the other pipeline connects to the inlet of the secondary reaction tower. The outlet of the secondary reaction tower connects to the second inlet of the primary reaction tower. The outlet of the primary reaction tower is connected to the inlet of the circulating pump. The gas inlet of the primary reaction tower is connected to a raw material gas pipeline, and the gas outlet of the primary reaction tower is connected to the gas inlet of the secondary reaction tower. The top outlet of the secondary reaction tower connects to a reprocessing pipeline. This invention ensures sufficient contact between the raw material gas and the catalyst, improving catalytic efficiency and making the reaction temperature easier to control, thus reducing the fluctuation range of the reaction temperature.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of preparation of chemical products, specifically a kind of production device and production method of vinyl chloride. BACKGROUND

[0002] At present, the main process of industrial production of vinyl chloride is to use calcium carbide method, which produces calcium carbide by taking coal and limestone as raw materials, and then generates acetylene by calcium carbide with water. The acetylene and hydrogen chloride gas mixture gas react to generate vinyl chloride under the action of catalyst. This reaction is a strong exothermic reaction. If the traditional fixed bed reactor is used to produce vinyl chloride, it will cause the surface of activated carbon supported HgCl2 catalyst to be locally overheated, the carbon deposition to block the pore, the contact area of catalyst and gas to be reduced, the local temperature to be high, the side reaction to be increased, the types and quantity of by-products to be increased, the subsequent product refining to be difficult, and the product quality to be affected.

[0003] CN113121303A discloses a vinyl chloride production process and a special device thereof. The device uses the flow of liquid catalyst to control the temperature in the reaction zone and avoid local overheating. However, the reaction tower in the device uses flowing liquid catalyst to react with the raw material gas. Although the raw material gas and the liquid catalyst react while flowing downward, the gas and the large droplets of liquid catalyst still directly contact, which inevitably causes local heat release. In actual production, the temperature control in the reaction tower is extremely strict. Once the temperature is not controlled well, the reaction temperature will fluctuate, which will cause hidden dangers to the safe operation of production. The safety defoamer uses solid mercury-free catalyst, which is a fixed bed reactor. Although the amount of unreacted raw material gas in the reaction product gas from the reaction tower is small, local high temperature will still occur on the surface of the catalyst, which will cause carbonization on the surface of the catalyst and affect the catalytic effect of the catalyst. Moreover, the device uses independent catalyst circulation systems in the reaction tower and the safety defoamer. As the production time increases, the catalytic efficiency of the liquid catalyst in the reaction tower and the safety defoamer will not be equivalent. In actual production, the catalytic efficiency of the catalyst needs to be detected separately, which increases the detection cost and difficulty. It also causes the quality of crude vinyl chloride gas to be unstable and increases the difficulty of subsequent treatment. Therefore, the existing vinyl chloride production device still needs to be further improved and perfected. SUMMARY

[0004] The purpose of the present application is to provide a production device and production method of vinyl chloride to solve the problems of high temperature control difficulty, large reaction temperature fluctuation in the reaction process, and low catalytic efficiency of the catalyst in the existing vinyl chloride production device.

[0005] The present invention is implemented as follows: a vinyl chloride production apparatus includes: a first reaction tower, a second reaction tower, a heat exchanger, a circulating pump, and a catalyst storage tank; the first gas inlet of the first reaction tower is the gas feed inlet, the first gas outlet of the first reaction tower is connected to the second gas inlet of the second reaction tower via a pipeline, the second liquid outlet of the second reaction tower is connected to the second liquid inlet of the first reaction tower via a pipeline, the pipeline connected to the first liquid outlet of the first reaction tower and the pipeline connected to the bottom liquid outlet of the catalyst storage tank are connected together to the liquid inlet of the circulating pump, the pipeline connected to the liquid outlet of the circulating pump is split into two paths after passing through the heat exchanger, one path is connected to the first liquid inlet of the first reaction tower via a first regulating valve, and the other path is connected to the second liquid inlet of the second reaction tower via a second regulating valve, and the first gas outlet of the first reaction tower is connected to the second gas inlet of the second reaction tower via a pipeline.

[0006] The reaction tower includes an upper head, a straight shell, a lower head, and several membrane tubes disposed in the straight shell. An orifice plate is disposed between the upper head and the straight shell, and a membrane tube is connected to each through hole of the orifice plate. A gas distributor is disposed below the orifice plate, and the gas inlet of the tower is connected to the gas distributor. The membrane tubes pass through the gas distributor of the tower and extend downward inside the straight shell.

[0007] Micropores are evenly distributed on the membrane tube. The upper end of the membrane tube is connected to a perforated plate, and the lower end of the membrane tube is sealed with a plug.

[0008] The gas distributor of the first tower has a double-ring structure, including an inner ring pipe and an outer ring pipe arranged concentrically. The inner ring pipe and the outer ring pipe are interconnected by several branch pipes. The outer ring pipe is connected to the gas inlet of the first tower through a main pipe. Several pinholes are opened at the lower part of the inner ring pipe, the outer ring pipe and the branch pipes. The gas outlet of the first tower is located above the second liquid inlet of the first tower.

[0009] A liquid distributor is installed inside the second reaction tower, and the liquid inlet of the second tower is connected to the liquid distributor. A gas-liquid separation pipe is installed in the tower body below the liquid distributor. The gas-liquid separation pipe is a "U"-shaped structure composed of a vertical pipe and an inclined pipe. The upper end of the vertical pipe is closed and the lower end is open. Several vent holes are distributed on the pipe wall. The vent holes are located at the upper part of the connection between the vertical pipe and the inclined pipe. The outer end of the inclined pipe is connected to the gas inlet of the second tower.

[0010] The liquid distributor of the two towers has a double-ring structure, including an inner ring pipe and an outer ring pipe arranged concentrically. The inner ring pipe and the outer ring pipe are interconnected by several branch pipes. The outer ring pipe is connected to the liquid inlet of the two towers through a main pipe. Several pinholes are opened at the bottom of the inner ring pipe, the outer ring pipe and the branch pipes.

[0011] Liquid flow regulating valves and liquid flow meters are installed on both output branches of the heat exchanger.

[0012] A gas flow regulating valve and a gas flow meter are arranged on the hydrogen chloride and acetylene mixed gas pipeline.

[0013] The method for producing vinyl chloride is realized by the following steps:

[0014] a. A vinyl chloride production device is arranged, which comprises a reaction column 1, a reaction column 2, a heat exchanger, a circulating pump and a catalyst storage tank; a column gas inlet of the reaction column 1 is connected with a raw material gas pipeline, a column gas outlet of the reaction column 1 is connected with a column 2 gas inlet of the reaction column 2 through a pipeline, a column 2 gas outlet of the reaction column 2 is connected with a reprocessing pipeline; a column 2 liquid outlet of the reaction column 2 is connected with a column 1 second liquid inlet of the reaction column 1 through a pipeline, a column 1 liquid outlet of the reaction column 1 is connected with a liquid inlet of the circulating pump through a pipeline, a bottom liquid outlet of the catalyst storage tank is connected with the circulating pump and the heat exchanger through a pipeline, and then branched into two paths, one path is connected with a column 1 first liquid inlet of the reaction column 1 through a first regulating valve, and the other path is connected with a column 2 liquid inlet of the reaction column 2 through a second regulating valve;

[0015] b. Liquid catalyst is added into the catalyst storage tank from a top liquid inlet of the catalyst storage tank, and the temperature in the catalyst storage tank is maintained at 100-120℃;

[0016] c. The liquid catalyst in the catalyst storage tank is sent into the reaction column 1 and the reaction column 2 through the pipeline from the column 1 first liquid inlet and the column 2 liquid inlet respectively by the circulating pump, and when there is a certain amount of liquid catalyst in the bottom of the reaction column 1 and the bottom of the reaction column 2, the valve at the bottom of the catalyst storage tank is closed, and the liquid catalyst in the reaction column 1 and the reaction column 2 is recycled, wherein the liquid catalyst enters the reaction column 1 from the column 1 first liquid inlet, enters the membrane tube inner passage through the orifice plate, and is uniformly dispersed into gas mist through the nanoscale micropores on the membrane tube under the action of pressure;

[0017] d. Acetylene and hydrogen chloride mixed gas is introduced into the reaction column 1 through a pipeline, the mixed gas is uniformly distributed in the gap between the membrane tubes in the reaction column 1 after passing through a column gas distributor, the liquid catalyst dispersed into gas mist contacts with the uniformly distributed raw material mixed gas to react, and the reaction gas product containing vinyl chloride is obtained at the lower part of the reaction column 1;

[0018] e. The reaction gas product containing vinyl chloride is introduced into the reaction column 2 through a pipeline to continue the reaction, and enters the reprocessing pipeline through a column 2 gas outlet of the reaction column 2.

[0019] Further, in step b, the flow rate ratio of the liquid catalyst in the reaction column 1 to the liquid catalyst in the reaction column 2 is (10-16):1;

[0020] Further, in the step c, the molar ratio of hydrogen chloride and acetylene in the mixed gas of acetylene and hydrogen chloride is (1.0-1.2):1; the reaction temperature in the reaction column I is 120-170 DEG C.

[0021] Further, in the step d, the reaction temperature in the reaction column II is 120-170 DEG C.

[0022] The outlet of the circulating pump is also connected with a regeneration pipeline, when the liquid catalyst needs to be regenerated or the equipment needs to be stopped, the liquid catalyst can be discharged from the regeneration pipeline, treated and then sent into the catalyst storage tank for recycling.

[0023] The present application establishes the liquid catalyst circulating system of the reaction column I and the reaction column II, so that the liquid catalysts entering the reaction column I and the reaction column II are equivalent, the activity of the liquid catalyst is more convenient to detect, the detection cost is reduced, and the quality of the crude vinyl chloride gas is not affected due to the different catalytic efficiencies in the two reaction columns; in addition, the gas-liquid separation pipe is arranged in the reaction column II, so that the liquid catalyst droplets in the gas product from the reaction column I flow to the bottom of the reaction column II along the inner wall of the standpipe under the action of gravity, the reaction gas containing vinyl chloride is uniformly dispersed into the reaction chamber of the reaction column II from the air holes in the upper segment of the standpipe, the unreacted acetylene and hydrogen chloride gas in the mixed gas continues to react to generate the product vinyl chloride under the action of the liquid catalyst, and the selectivity and purity of the product vinyl chloride are improved.

[0024] In the present application, the membrane pipe is arranged in the reaction column I, the liquid catalyst is uniformly dispersed into the gas mist, the gas mist of the liquid catalyst directly contacts the mixed gas uniformly distributed in the reaction column I to react, the contact is more sufficient, in the reaction process, the gas mist of the liquid catalyst condenses into large droplets to absorb the reaction heat and falls into the bottom of the reaction column I, and then is circulated back to the reaction column I to continue to participate in the reaction after being cooled by the heat exchanger on the external circulation pipeline. The present application changes the liquid catalyst into the gas mist by the membrane pipe, so that the raw gas and the catalyst are fully contacted, the catalytic efficiency is improved, the reaction temperature in the reaction process is more convenient to control, the fluctuation range of the reaction temperature is reduced, and the safety of the equipment use is improved. The heat exchangers are arranged on the external circulation pipelines of the reaction column I and the reaction column II, and the jackets are arranged outside the two columns, so that the temperature inside the two columns can be more accurately controlled, and the temperature fluctuation range inside the two columns is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is the device structure and process flow schematic diagram of the present application.

[0026] Figure 2 It is the reaction column I structure schematic diagram of the present application.

[0027] Figure 3 is a schematic diagram of the reaction two-tower structure of the present application.

[0028] Figure 4 is a schematic diagram of the liquid distributor structure of the present application.

[0029] Figure 5 is a schematic diagram of the orifice plate structure.

[0030] In the figure: 1, reaction one-tower; 2, reaction two-tower; 3, catalyst storage tank; 4, circulating pump; 5, heat exchanger; 6, third regulating valve; 7, second regulating valve; 8, first regulating valve; 101, first liquid inlet of one-tower; 102, pressure monitoring port; 103, temperature monitoring port; 104, one-tower gas outlet; 105, second liquid inlet of one-tower; 106, liquid level monitoring port; 107, one-tower liquid outlet; 108, plug; 109, membrane tube; 110, membrane tube inner passage; 111, one-tower gas distributor; 112, one-tower gas inlet; 113, orifice plate; 114, upper head; 201, two-tower gas inlet; 202, gas-liquid separation tube; 203, two-tower liquid outlet; 204, two-tower liquid inlet; 205, two-tower gas outlet; 206, two-tower liquid distributor; 207, two-tower reaction chamber; 1111, outer ring tube; 1112, inner ring tube; 1113, branch pipe; 1114, main pipe; 1131, through-hole; 2021, inclined pipe; 2022, vertical pipe; 2023, air vent hole, A, hydrogen chloride; B, acetylene; C, chloroethylene; E, liquid catalyst to be treated. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0032] As Figure 1As shown, the vinyl chloride production device of the present application comprises a first reaction column 1, a second reaction column 2, a heat exchanger 5, a circulating pump 4 and a catalyst storage tank 3. The bottom liquid outlet of the catalyst storage tank 3 is connected in series with the circulating pump 4 and the heat exchanger 5 through a pipeline, and then two pipelines are branched, one of which is connected to a first column first liquid inlet 101 at the top of the first reaction column 1, and the other is connected to a second column liquid inlet 204 of the second reaction column 2. The second column liquid outlet 203 of the second reaction column 2 is connected to a first column second liquid inlet 105 of the first reaction column 1 through a pipeline. The first column liquid outlet 107 of the first reaction column 1 is connected to the liquid inlet of the circulating pump 4 through a pipeline. A first column gas inlet 112 is connected to a pipeline of mixed gas of hydrogen chloride A and acetylene B. The mixed gas of hydrogen chloride A and acetylene B enters the inside of the first reaction column 1 from the first column gas inlet 112, and then reacts in the reaction chamber of the first reaction column 1 under the action of liquid catalyst to generate a reaction gas product containing vinyl chloride. The first column gas outlet 104 of the first reaction column 1 is connected to the second column gas inlet 201 of the second reaction column 2 through an upwardly inclined pipeline. The reaction gas product containing vinyl chloride enters the inside of the second reaction column 2 from the second column gas inlet 201 through a pipeline. The unreacted hydrogen chloride A and acetylene B continue to react in the second column reaction chamber 207 of the second reaction column 2, so that the reaction gas product containing vinyl chloride from the first reaction column 1 fully reacts to generate a gas product vinyl chloride C. Finally, the gas product vinyl chloride C enters a post-processing pipeline through the second column gas outlet 205 at the top of the second reaction column 2.

[0033] As shown, Figure 2 The first reaction column 1 comprises an upper head 114, a straight cylinder shell and a lower head connected in sequence by flanges. A perforated plate 113 is arranged between the flange of the upper head 114 and the flange of the straight cylinder shell (as shown in Figure 5 A plurality of membrane tubes 109 are connected to the perforated plate 113, and the membrane tubes 109 are arranged one-to-one corresponding to the through holes 1131 of the perforated plate 113. The top end of the membrane tube 109 passes through the through hole 1131 and is aligned with the upper plane of the perforated plate 113. The connection between the membrane tube 109 and the perforated plate 113 can be one of sleeving, clamping or threaded connection, and a sealing ring is arranged between the membrane tube 109 and the through hole 1131. A first column gas distributor 111 is arranged below the perforated plate 113 (as shown in Figure 4As shown in the figure, a one-tower gas distributor 111 has a multi-ring structure, and is provided with an outer ring pipe 1111, an inner ring pipe 1112, branch pipes 1113 and a main pipe 1114. The main pipe 1114 is connected to a one-tower air inlet 112. A number of pinholes are also opened at the lower parts of the outer ring pipe 1111, the inner ring pipe 1112 and the branch pipes 1113. A membrane tube 109 is inserted between the outer ring pipe 1111 and the inner ring pipe 1112 of the one-tower gas distributor 111, and a membrane tube 109 is also sleeved inside the inner ring pipe 1112. The membrane tube 109 is a tubular hollow membrane tube, the upper end of which is open and connected to the upper chamber of the reaction one-tower 1, and a plug 108 is installed at the lower end. A number of nano-scale micropores are evenly arranged on the membrane tube 109. The mixed gas of hydrogen chloride A and acetylene B entering the reaction one-tower 1 is evenly distributed into the reaction one-tower 1 by the one-tower gas distributor 111, and undergoes a catalytic reaction with the liquid catalyst permeating from the membrane tube 109. Under the action of pressure, the liquid catalyst penetrates from the inner channel 110 of the membrane tube through the nano-scale micropores into the reaction chamber of the reaction one-tower 1, and undergoes a catalytic reaction with the mixed gas of hydrogen chloride A and acetylene B in the form of aerosol to generate a reaction gas product containing vinyl chloride. Pressure monitoring ports 102, temperature monitoring ports 103 and liquid level monitoring ports 106 are also provided on the tower wall of the reaction one-tower 1 as required to monitor and control the internal conditions of the reaction one-tower 1. A jacket is also provided outside the reaction one-tower 1, and cold and heat source inlets and outlets are provided on the jacket to further control the temperature inside the reaction one-tower 1.

[0034] As Figure 3 As shown in the figure, a two-tower liquid distributor 206 with the same structure as the one-tower gas distributor 111 is arranged in the reaction two-tower 2. The main pipe of the two-tower liquid distributor 206 is connected to a two-tower liquid inlet 204, and a "卜"-shaped gas-liquid separation pipe 202 is arranged below the two-tower liquid distributor 206. The gas-liquid separation pipe 202 includes an inclined pipe 2021 and a vertical pipe 2022 that are connected to each other. One end of the inclined pipe 2021 is connected to the vertical pipe 2022, and the other end is connected to a two-tower air inlet 201. The upper end of the vertical pipe 2022 is closed and the lower end is open, and a number of ventilation holes 2023 are also opened on the vertical pipe 2022. The ventilation holes 2023 are located above the connection between the vertical pipe 2022 and the inclined pipe 2021. The liquid catalyst droplets in the gas product from the reaction one-tower 1 flow along the inner wall of the vertical pipe 2022 to the bottom of the reaction two-tower 2 under the action of their own gravity, and the reaction gas containing vinyl chloride is evenly dispersed into the two-tower reaction chamber 207 through the ventilation holes 2023. The unreacted acetylene B and hydrogen chloride A gases in the mixed gas continue to react to generate the product vinyl chloride under the action of the liquid catalyst. Pressure monitoring ports 102, temperature monitoring ports 103 and liquid level monitoring ports 106 are also provided on the tower wall of the reaction two-tower 2 to monitor and control the internal conditions of the reaction two-tower 2. A jacket is also provided outside the reaction two-tower 2, and cold and heat source inlets and outlets are provided on the jacket to further control the temperature inside the reaction two-tower 2.

[0035] The heat exchanger 5 is provided with catalyst inlet and outlet, and cold and hot source inlet and outlet, which is used for cooling liquid catalyst and by-product steam or hot water.

[0036] The first regulating valve 8 and liquid flow meter are arranged on the liquid inlet pipeline connected with the first liquid inlet 101 of the tower, the second regulating valve 7 and liquid flow meter are arranged on the liquid inlet pipeline of the reaction tower 2, and the third regulating valve 6 and gas flow meter are arranged on the gas inlet pipeline of the reaction tower 1. The circulating pump 4, the first regulating valve 8, the second regulating valve 7, the third regulating valve 6 and the corresponding liquid flow meter and gas flow meter and the pressure monitor, the temperature monitor and the liquid level monitor arranged on the reaction tower 1 and the reaction tower 2 form a catalyst circulating system of the reaction tower 1 and the reaction tower 2 which can be temperature controlled and flow controlled, and is used for realizing high-efficiency recycling of catalyst during normal operation of the device.

[0037] The method for producing vinyl chloride comprises the following steps:

[0038] a. A vinyl chloride production device is arranged, which comprises a reaction tower 1, a reaction tower 2, a heat exchanger 5, a circulating pump 4 and a catalyst storage tank 3; the one-tower gas inlet 112 of the reaction tower 1 is connected with a raw gas pipeline, the one-tower gas outlet 104 of the reaction tower 1 is connected with the two-tower gas inlet 201 of the reaction tower 2 through a pipeline, the two-tower liquid outlet 203 of the reaction tower 2 is connected with the one-tower second liquid inlet 105 of the reaction tower 1 through a pipeline, the one-tower liquid outlet 107 of the reaction tower 1 is connected with the liquid inlet of the circulating pump 4 through a pipeline, the bottom liquid outlet of the catalyst storage tank 3 is connected with the circulating pump 4 and the heat exchanger 5 through a pipeline, and then two pipelines are branched, one of which is connected with the one-tower first liquid inlet 101 of the reaction tower 1 through the first regulating valve 8, and the other of which is connected with the two-tower liquid inlet 204 of the reaction tower 2 through the second regulating valve 7;

[0039] b. Liquid catalyst is added into the catalyst storage tank 3 from the top liquid inlet of the catalyst storage tank 3, and the temperature in the catalyst storage tank 3 is kept between 100-120 DEG C;

[0040] c. using the circulating pump 4 to send the liquid catalyst in the catalyst storage tank 3 to the first liquid inlet 101 of the first reactor 1 and the second liquid inlet 204 of the second reactor 2 through the pipelines, respectively, when there is a certain amount of liquid catalyst in the bottom of the first reactor 1 and the second reactor 2, the output pipeline of the catalyst storage tank 3 is closed to establish a circulating flow path, in the first reactor 1, the liquid catalyst enters the membrane tube channel 110 through the orifice plate 113 after entering the tower from the top, and is uniformly dispersed into a gas mist under the action of pressure through the nanoscale micropores on the membrane tube 109; wherein the ratio of the flow rate of the liquid catalyst in the first reactor 1 to the flow rate of the liquid catalyst in the second reactor 2 is (10-16): 1;

[0041] d. the acetylene B and hydrogen chloride A mixed gas is introduced into the first reactor 1 through the pipeline; the mixed gas is uniformly distributed in the gap between the membrane tubes 109 in the first reactor 1 through the gas distributor 111, and the liquid catalyst dispersed into a gas mist in the gap between the membrane tubes 109 is contacted with the uniformly distributed raw material mixed gas to carry out the reaction, and the reaction gas product containing vinyl chloride is obtained in the lower part of the first reactor 1; the reaction temperature in the first reactor 1 is 120-170℃; the molar ratio of hydrogen chloride A to acetylene B in the acetylene B and hydrogen chloride A mixed gas is (1.0-1.2): 1;

[0042] e. the reaction gas product containing vinyl chloride is introduced into the second reactor 2 through the pipeline to continue the reaction, and the product vinyl chloride gas C is introduced out through the reprocessing pipeline at the top of the second reactor 2, wherein the reaction temperature in the second reactor 2 is 120-170℃.

[0043] In the present application, the conversion rate of acetylene can reach more than 99%, and the selectivity of vinyl chloride can reach more than 99.5%.

[0044] The above only describes the preferred embodiments of the present application and is not intended to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A vinyl chloride production apparatus, characterized in that, include: The system comprises a first reaction tower, a second reaction tower, a heat exchanger, a circulating pump, and a catalyst storage tank. The first gas inlet of the first reaction tower is the gas feed inlet. The first gas outlet of the first reaction tower is connected to the second gas inlet of the second reaction tower via a pipeline. The second liquid outlet of the second reaction tower is connected to the second liquid inlet of the first reaction tower via a pipeline. The pipeline connected to the first liquid outlet of the first reaction tower and the pipeline connected to the liquid outlet at the bottom of the catalyst storage tank are connected together to the liquid inlet of the circulating pump. The pipeline connected to the liquid outlet of the circulating pump is split into two paths after passing through the heat exchanger. One path is connected to the first liquid inlet of the first reaction tower via a first regulating valve, and the other path is connected to the second liquid inlet of the second reaction tower via a second regulating valve. The first gas outlet of the first reaction tower is connected to the second gas inlet of the second reaction tower via a pipeline. The reaction tower includes an upper head, a straight shell, a lower head, and several membrane tubes disposed in the straight shell; an orifice plate is disposed between the upper head and the straight shell, and a membrane tube is connected to each through hole of the orifice plate; a gas distributor is disposed below the orifice plate; the gas inlet of the tower is connected to the gas distributor; the membrane tubes pass through the gas distributor of the tower and extend downward inside the straight shell; the gas outlet of the tower is located above the second liquid inlet of the tower. Micropores are evenly distributed on the membrane tube, the upper end of the membrane tube is connected to the orifice plate, and the lower end of the membrane tube is sealed with a plug. A liquid distributor is installed inside the second reaction tower, and the liquid inlet of the second tower is connected to the liquid distributor. A gas-liquid separation pipe is installed in the tower body below the liquid distributor. The gas-liquid separation pipe is a "U"-shaped structure composed of a vertical pipe and an inclined pipe. The upper end of the vertical pipe is closed and the lower end is open. Several vent holes are distributed on the pipe wall. The vent holes are located at the upper part of the connection between the vertical pipe and the inclined pipe. The outer end of the inclined pipe is connected to the gas inlet of the second tower.

2. The vinyl chloride production apparatus according to claim 1, characterized by The gas distributor of the tower has a double-ring structure, including an inner ring pipe and an outer ring pipe arranged concentrically. The inner ring pipe and the outer ring pipe are interconnected by several branch pipes. The outer ring pipe is connected to the gas inlet of the tower through a main pipe. Several pinholes are opened at the bottom of the inner ring pipe, the outer ring pipe and the branch pipes.

3. The vinyl chloride production apparatus according to claim 1, characterized by The liquid distributor of the two towers has a double-ring structure, including an inner ring pipe and an outer ring pipe arranged concentrically. The inner ring pipe and the outer ring pipe are interconnected by several branch pipes. The outer ring pipe is connected to the liquid inlet of the two towers through a main pipe. Several pinholes are opened at the bottom of the inner ring pipe, the outer ring pipe and the branch pipes.

4. A process for the production of vinyl chloride characterized by, Includes the following steps: a. Install the vinyl chloride production apparatus according to any one of claims 1-3; b. Add the liquid catalyst into the catalyst storage tank through the top inlet, and maintain the temperature inside the catalyst storage tank between 100-120°C. c. Using a circulating pump, the liquid catalyst in the catalyst storage tank is sent through pipelines from the first inlet of the first tower and the inlet of the second tower to the first reaction tower and the second reaction tower, respectively. When a certain amount of liquid catalyst is stored at the bottom of the first reaction tower and the bottom of the second reaction tower, the bottom valve of the catalyst storage tank is closed, and the liquid catalyst in the first reaction tower and the second reaction tower is recycled. d. passing the mixed gas of acetylene and hydrogen chloride into the first reactor through a pipeline, the mixed gas being uniformly distributed in the gaps between the membrane tubes after passing through the gas distributor of the first reactor, and reacting under the action of the liquid catalyst to obtain a reaction gas product containing vinyl chloride at the lower part of the first reactor; e. passing the reaction gas product containing vinyl chloride into the second reactor through a pipeline to continue the reaction, and leading out the product vinyl chloride gas through the reprocessing pipeline at the top of the second reactor.

5. The vinyl chloride production method according to claim 4, characterized by In step c, the flow rate ratio of the liquid catalyst in the first reactor to the liquid catalyst in the second reactor is (10-16):1; In step d, the molar ratio of hydrogen chloride to acetylene in the mixed gas of acetylene and hydrogen chloride is (1.0-1.2):1; and the reaction temperature in the first reactor is 120-170℃.

6. The vinyl chloride production method according to claim 4, characterized by In step e, the reaction temperature in the second reactor is 120-170℃.

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