Liquid phase catalytic solution for synthesizing vinyl chloride by acetylene hydrochlorination, use thereof, and method, device and use method for synthesizing vinyl chloride

Abstract

The present invention provides a liquid-phase catalytic solution for synthesizing vinyl chloride by acetylene hydrochlorination, its use, and a method, device, and method for synthesizing vinyl chloride. The solubility of the liquid-phase catalytic solution for acetylene at normal temperature and pressure is ≥2%, and the solubility of the liquid-phase catalytic solution for hydrogen chloride is >5% at 100-160°C. The liquid-phase catalytic solution has a catalytic effect on synthesizing vinyl chloride by acetylene hydrochlorination, and is used for synthesizing vinyl chloride by acetylene hydrochlorination. The method comprises the following steps: 1) acetylene is introduced into a liquid-phase catalytic solution containing hydrogen chloride, and the liquid-phase catalytic solution containing hydrogen chloride absorbs acetylene to saturation; 2) acetylene and hydrogen chloride in the catalytic solution react to synthesize vinyl chloride at the temperature and pressure of the acetylene hydrochlorination reaction; 3) desorption, while introducing hydrogen chloride to dissolve, to obtain crude vinyl chloride and a liquid-phase catalytic solution containing hydrogen chloride, respectively; the liquid-phase catalytic solution containing hydrogen chloride is refluxed to step 1) to continue to absorb acetylene. The present invention makes the acetylene reaction more thorough and the desorption efficiency of vinyl chloride higher.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical production, and in particular to a liquid-phase catalytic solution for synthesizing vinyl chloride by liquid-phase acetylene hydrochlorination, its application, and a method, device and use method for synthesizing vinyl chloride. Background Art

[0002] Vinyl chloride is the monomer for synthesizing polyvinyl chloride, which is one of the largest-volume resins in the world. It has excellent mechanical strength, stable chemical properties, and is easy to process. It is widely used in industry, agriculture, building materials, and daily necessities. China is the largest producer and consumer of polyvinyl chloride.

[0003] Due to the resource characteristics of my country, which is rich in coal, poor in oil and little in gas, about 80% of the vinyl chloride production capacity adopts the calcium carbide process, that is, acetylene and hydrogen chloride are used to synthesize vinyl chloride under the action of solid-phase catalysts. Since solid-phase catalysis can easily cause local overheating of the catalyst surface, carbon deposits will be generated to block the pores, reduce the contact area between the catalyst and the raw gas, cause the catalyst to deactivate quickly, and reduce the catalytic efficiency. Overheating will also increase side reactions and increase the types and quantities of by-products, making it difficult to refine subsequent products and affecting product quality.

[0004] Therefore, many researchers have attempted to solve the problems existing in the fixed-bed process of acetylene hydrochlorination to synthesize vinyl chloride through a liquid-phase catalytic process.

[0005] Application No. 201910940747.8 provides a gas-liquid phase vinyl chloride production process and device. A mixed gas of acetylene and hydrogen chloride is introduced from the bottom of the kettle to react with a liquid phase catalyst in reverse to generate vinyl chloride. During the reaction, the temperature of the reaction is controlled by a heat exchanger. The generated vinyl chloride gas flows out from the liquid catalyst, and the liquid catalyst is cooled and liquefied when passing through the condenser with the vinyl chloride gas, and then refluxed to the reaction zone to act on the reaction again. The liquid catalyst is one of imidazole hydrochloride, nitrogen methyl pyrrolidone hydrochloride, choline chloride or quaternary phosphonium salt; the active component of the liquid catalyst is one of cupric chloride, cuprous chloride, tin chloride and ruthenium trichloride.

[0006] Application No. 200910236255.7 discloses a catalyst system for preparing vinyl chloride by hydrochlorination of acetylene, and its preparation and application. The catalyst system comprises a catalyst carrier and a catalyst, wherein the catalyst carrier is an imidazole ionic liquid, and the catalyst is one of chlorides of gold, platinum, palladium, tin, mercury, copper or rhodium or any combination of two or more thereof. The catalyst is dissolved in the catalyst carrier, and acetylene and hydrogen chloride gases are mixed and reacted in the presence of the catalyst system.

[0007] Application No. 201010185916.0 discloses a catalyst system for preparing vinyl chloride by hydrochlorination of acetylene, and its preparation and application. The catalyst system comprises a catalyst carrier and a catalyst, wherein the catalyst carrier is a pyridine ionic liquid, and the catalyst is one of chlorides of tin, palladium, platinum, gold, copper, manganese, bismuth, mercury or rhodium, or any combination of two or more thereof. The preparation method of the above catalyst system is to dissolve the catalyst in the catalyst carrier, and then mix the two gases of acetylene and hydrogen chloride and simultaneously introduce them into the liquid catalyst system for reaction.

[0008] Application No. 202221389596.5 provides a tower-type gas-liquid phase vinyl chloride production device. The vinyl chloride synthesis tower is used for gas-liquid countercurrent or cocurrent contact reaction, and is divided into a gas phase zone, a gas-liquid reaction zone, and a gas-liquid separation zone from top to bottom; during operation, the raw gas reacts with the liquid catalyst in the gas-liquid reaction zone, the liquid catalyst after the reaction enters the catalyst storage tank, and the crude product gas after the reaction enters the condenser, which is used to condense and separate the liquid catalyst carried in the crude product gas.

[0009] The acetylene-hydrochlorination liquid phase reaction described in the above invention application adopts the method of synchronous intake of acetylene and hydrogen chloride. However, due to the large difference in the solubility of acetylene and hydrogen chloride in the catalytic solution, there are problems such as asymmetric absorption rate of the raw gas, difficulty in synchronous reaction, and low reaction efficiency.

[0010] In order to solve the technical problems of synchronous intake of acetylene and hydrogen chloride, the invention patent application with application number CN202110885998.8 provides a method for preparing vinyl chloride by liquid phase catalysis, which introduces a polar organic solvent as the reaction solvent of the catalytic system, uses a metal compound as a catalyst, and the catalytic solution first absorbs hydrogen chloride and then absorbs acetylene to react under pressure, and finally resolves to obtain vinyl chloride. Although this invention application adopts the method of absorbing hydrogen chloride and acetylene in steps, since the absorption of hydrogen chloride and the desorption of vinyl chloride are carried out separately, there are problems such as long process flow, high energy consumption, and poor desorption effect. Summary of the invention

[0011] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a liquid-phase catalytic solution for synthesizing vinyl chloride by acetylene hydrochlorination, its use, and a method, device and use method for synthesizing vinyl chloride. The acetylene hydrochlorination reaction has high efficiency, simplified process and reduced production energy consumption.

[0012] To achieve the above-mentioned object and other related objects, the first aspect of the present invention provides a liquid-phase catalytic solution for the liquid-phase synthesis of vinyl chloride by acetylene hydrochlorination, wherein the solubility of the liquid-phase catalytic solution for acetylene at room temperature and pressure is ≥2%, and the solubility of the liquid-phase catalytic solution for hydrogen chloride at 100-160°C is >5%, and the liquid-phase catalytic solution has a catalytic effect on the synthesis of vinyl chloride by acetylene hydrochlorination.

[0013] Normal temperature refers to 25°C, and normal pressure refers to a gauge pressure of 0 MPa.

[0014] Solubility refers to the mass that can be dissolved in 100g of solvent when it reaches saturation. For example, if the solubility of acetylene is ≥2%, it means that the mass that can be dissolved in 100g of liquid catalytic solution when acetylene reaches saturation is ≥2g; if the solubility of hydrogen chloride is >5%, it means that the mass that can be dissolved in 100g of liquid catalytic solution when hydrogen chloride reaches saturation is >5g.

[0015] Preferably, the liquid phase catalytic solution is a liquid phase non-metallic catalytic solution and / or a liquid phase metal catalytic solution;

[0016] The liquid non-metallic catalytic solution comprises a first component and a second component, the first component is selected from at least one of an imidazole compound and an imidazole chloride salt, and the second component is an amide solvent;

[0017] The liquid metal catalytic solution comprises at least one selected from a first component and a second component and a third component, wherein the third component is a metal chloride.

[0018] More preferably, the imidazole compound is an imidazole compound in which a hydrogen group in NH is substituted by a C1-C6 alkyl group;

[0019] And / or, the imidazolium chloride salt is an N-substituted imidazolium salt, and the substituent is a C1-C6 alkyl group;

[0020] And / or, the amide solvent is an amide compound in which a hydrogen group in NH is substituted by a C1-C6 alkyl group;

[0021] And / or, the metal chloride is selected from at least one of cupric chloride, cuprous chloride, gold chloride, palladium chloride, platinum chloride, ruthenium chloride and iridium chloride;

[0022] And / or, in the liquid non-metallic catalytic solution, the mass percentage of the first component is 5-95%, such as 5-35% or 35-95%, and the mass percentage of the second component is 5-95%, such as 5-65% or 65-95%;

[0023] And / or, in the liquid metal catalytic solution, the mass percentage of the first component is 5-94.5%, such as 5-20%, 20-50%, 50-79% or 79-94.5%, the mass percentage of the second component is 5-94.5%, 5-20.5%, 20.5-30%, 30-50% or 50-94.5%, and the mass percentage of the third component is 0.5-30%, such as 0.5-20% or 20-30%.

[0024] More preferably, the imidazole compound is selected from at least one of N-methylimidazole, N-ethylimidazole, N-propylimidazole, N-butylimidazole, N-cyclohexylimidazole, N-isopropylimidazole and N-isobutylimidazole;

[0025] And / or, the imidazolium chloride salt is selected from at least one of 1-methyl-3-ethylimidazolium chloride, 1-ethyl-3-methylimidazolium chloride, 1-methyl-3-butylimidazolium chloride, 1-ethyl-3-ethylimidazolium chloride, 1-butyl-3-methylimidazolium chloride, 1,3-dimethylimidazolium chloride, 1,3-diisopropylimidazolium chloride and 1-hexyl-3-methylimidazolium chloride;

[0026] And / or, the amide solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methylpyrrolidone, N-propylpyrrolidone, N-isopropylpyrrolidone, N-cyclohexylpyrrolidone and N-ethylpyrrolidone.

[0027] The second aspect of the present invention provides the use of the above-mentioned liquid-phase catalytic solution in the liquid-phase synthesis of vinyl chloride by acetylene hydrochlorination.

[0028] The third aspect of the present invention provides a method for synthesizing vinyl chloride by liquid phase hydrochlorination of acetylene, comprising the following steps:

[0029] 1) introducing acetylene into the liquid-phase catalytic solution containing hydrogen chloride, so that the liquid-phase catalytic solution containing hydrogen chloride absorbs acetylene until saturation, thereby obtaining a catalytic solution absorbing acetylene;

[0030] 2) subjecting the catalytic solution to a temperature and pressure for acetylene hydrochlorination reaction to react acetylene and hydrogen chloride in the catalytic solution to synthesize vinyl chloride, thereby obtaining a reaction solution;

[0031] 3) Desorbing the reaction solution, while introducing hydrogen chloride to dissolve, to obtain crude vinyl chloride and a liquid catalytic solution containing hydrogen chloride, respectively; the liquid catalytic solution containing hydrogen chloride is refluxed to step 1) to continue absorbing acetylene.

[0032] Preferably, it also includes at least one of the following technical features:

[0033] 11) In step 1), the amount of acetylene absorbed is >2wt% of the mass of the liquid catalytic solution containing hydrogen chloride, such as >2wt% and ≤4wt%, 4-4.2wt%, 4.2-5.3wt%, 5.3-6.2wt%, 6.2-8.1wt%, 8.1-8.7wt%, 8.7-10.3wt%, 10.3-10.4wt% or ≥10.4wt%;

[0034] 12) In step 1), the temperature for absorbing acetylene is -30 to 50°C, such as -30 to -10°C, -10 to 0°C, 0 to 10°C, 10 to 20°C, 20 to 30°C or 30 to 50°C;

[0035] 21) In step 2), the temperature of the acetylene hydrochlorination reaction is 80-160°C, such as 80-110°C, 110-120°C, 120-130°C, 130-140°C, 140-150°C or 150-160°C;

[0036] 22) In step 2), the pressure (gauge pressure) of the acetylene hydrochlorination reaction is 0.05 to 3.0 MPa, such as 0.05 to 0.5 MPa, 0.5 to 1 MPa, 1 to 1.2 MPa, 1.2 to 2.5 MPa or 2.5 to 3 MPa;

[0037] 23) In step 2), the acetylene conversion rate in the synthesis of vinyl chloride by the reaction of acetylene and hydrogen chloride is above 95%, such as 95-96.5%, 96.5-97%, 97-98%, 98-98.5% or above 98.5%;

[0038] 31) In step 3), the desorption temperature is 100-170°C, such as 100-130°C, 130-140°C, 140-150°C, 150-160°C or 160-170°C;

[0039] 32) In step 3), the desorption pressure is 0 to 0.5 MPa, such as 0 to 0.05 MPa, 0.05 to 0.1 MPa, 0.1 to 0.3 MPa or 0.3 to 0.5 MPa;

[0040] 33) In step 3), the molar ratio of the amount of hydrogen chloride introduced to the amount of acetylene introduced in step 1) is 1:1;

[0041] 34) The liquid catalytic solution containing hydrogen chloride obtained in step 3) is heat exchanged with the catalytic solution in step 2) and then refluxed to step 1) to continue absorbing acetylene. The catalytic solution in step 2) absorbs the heat of the liquid catalytic solution containing hydrogen chloride obtained in step 3), thereby increasing the temperature of the acetylene hydrochlorination reaction and effectively utilizing the heat of solution of hydrogen chloride in step 3).

[0042] The pressures mentioned above are gauge pressures.

[0043] The fourth aspect of the present invention provides a device for synthesizing vinyl chloride by acetylene hydrochlorination in liquid phase, comprising an absorption tower, a pipeline reactor and a desorption tower; the desorption tower is provided with a first feed inlet for introducing a liquid phase catalytic solution containing hydrogen chloride, a second feed inlet for introducing acetylene and a first discharge port for discharging the catalytic solution absorbed acetylene; the desorption tower is provided with a third feed inlet for introducing a reaction solution, a fourth feed inlet for introducing hydrogen chloride gas, a second discharge port for discharging crude vinyl chloride and a third discharge port for discharging a liquid phase catalytic solution containing hydrogen chloride;

[0044] The first discharge port is connected to the third feed port via the pipeline reactor;

[0045] The third discharge port is connected to the first feed port.

[0046] Preferably, the first feed inlet is arranged at the top of the absorption tower;

[0047] And / or, the second feed inlet is arranged at the bottom of the absorption tower;

[0048] And / or, the first discharge port is arranged at the bottom of the absorption tower;

[0049] And / or, the third feed inlet is arranged at the top of the desorption tower;

[0050] And / or, the fourth feed inlet is arranged at the bottom of the desorption tower;

[0051] And / or, the second discharge port is arranged at the top of the desorption tower;

[0052] And / or, the third discharge port is arranged at the bottom of the desorption tower;

[0053] And / or, the pipeline reactor is provided with a fifth feed port for introducing a catalytic solution for absorbing acetylene and a fourth discharge port for discharging the reaction solution, the fifth feed port is connected to the first discharge port, and the fourth discharge port is connected to the third feed port;

[0054] And / or, the pipeline reactor is provided with a heat source channel, the third discharge port is connected to the first feed port via the heat source channel, the heat source channel may be a bypass pipe, a jacket, etc., the liquid-phase catalytic solution that absorbs hydrogen chloride exchanges heat with the catalytic solution via the heat source channel of the pipeline reactor, so that the reaction liquid in the pipeline reactor is heated, thereby effectively utilizing the dissolution heat of hydrogen chloride.

[0055] A fifth aspect of the present invention provides a method for using the above device, comprising the following steps:

[0056] 1) introducing a liquid-phase catalytic solution containing hydrogen chloride and acetylene into the absorption tower through the first feed port and the second feed port, respectively, the liquid-phase catalytic solution containing hydrogen chloride absorbs acetylene to saturation to obtain a catalytic solution absorbing acetylene, and the catalytic solution absorbing acetylene is discharged through the first discharge port;

[0057] 2) passing the catalytic solution that absorbs acetylene into the pipeline reactor, and causing acetylene and hydrogen chloride in the catalytic solution to react to synthesize vinyl chloride under the temperature and pressure of acetylene hydrochlorination reaction to obtain a reaction solution;

[0058] 3) introducing the reaction solution and hydrogen chloride into the desorption tower through the third feed port and the fourth feed port, respectively, desorbing the reaction solution, and introducing hydrogen chloride to dissolve, to obtain crude vinyl chloride and a liquid-phase catalytic solution containing hydrogen chloride, respectively; the crude vinyl chloride is discharged through the second discharge port, and the liquid-phase catalytic solution containing hydrogen chloride is discharged through the third discharge port and refluxed into the absorption tower through the first feed port to continue absorbing acetylene.

[0059] Preferably, it also includes at least one of the following technical features:

[0060] 11) In step 1), the absorption amount of acetylene in the absorption tower is greater than 2wt% of the mass of the liquid catalytic solution containing hydrogen chloride, such as greater than 2wt% and ≤4wt%, 4-4.2wt%, 4.2-5.3wt%, 5.3-6.2wt%, 6.2-8.1wt%, 8.1-8.7wt%, 8.7-10.3wt%, 10.3-10.4wt% or ≥10.4wt%;

[0061] 12) In step 1), the temperature of absorbing acetylene in the absorption tower is -30 to 50°C, such as -30 to -10°C, -10 to 0°C, 0 to 10°C, 10 to 20°C, 20 to 30°C or 30 to 50°C;

[0062] 13) In step 1), the liquid phase catalytic solution is the above-mentioned liquid phase catalytic solution;

[0063] 21) In step 2), the temperature of the acetylene hydrochlorination reaction in the pipeline reactor is 80-160°C, such as 80-110°C, 110-120°C, 120-130°C, 130-140°C, 140-150°C or 150-160°C;

[0064] 22) The pressure of the acetylene hydrochlorination reaction in the pipeline reactor is 0.05-3.0 MPa, such as 0.05-0.5 MPa, 0.5-1 MPa, 1-1.2 MPa, 1.2-2.5 MPa or 2.5-3 MPa;

[0065] 23) In step 2), the acetylene conversion rate in the synthesis of vinyl chloride by the reaction of acetylene and hydrogen chloride is above 95%, such as 95-96.5%, 96.5-97%, 97-98%, 98-98.5% or above 98.5%;

[0066] 31) In step 3), the desorption temperature in the desorption tower is 100-170°C, such as 100-130°C, 130-140°C, 140-150°C, 150-160°C or 160-170°C;

[0067] 32) The desorption pressure in the desorption tower is 0-0.5 MPa, such as 0-0.05 MPa, 0.05-0.1 MPa, 0.1-0.3 MPa or 0.3-0.5 MPa;

[0068] 33) In step 3), the molar ratio of the amount of hydrogen chloride introduced into the desorption tower to the amount of acetylene introduced into the absorption tower is 1:1;

[0069] 34) In step 3), the liquid catalytic solution containing hydrogen chloride is discharged through the third outlet and sequentially refluxed through the heat source channel of the pipeline reactor and the first feed inlet to the absorption tower to continue absorbing acetylene.

[0070] As described above, the above technical solution has at least one of the following beneficial effects:

[0071] 1) In the above technical solution, the liquid catalytic solution has a better solubility for hydrogen chloride. When desorbing vinyl chloride, hydrogen chloride will not be taken out by the gas phase, so that the product gas does not contain hydrogen chloride, the alkaline water washing process is omitted, and the amount of waste acid and equipment investment are greatly reduced.

[0072] 2) The above technical solution adopts a combination of an absorption tower, a pipeline reactor and a desorption tower to absorb acetylene and hydrogen chloride, making full use of the solubility characteristics and reaction heat of the materials to make the acetylene reaction more thorough, the desorption efficiency of vinyl chloride higher, and the continuity is good, which is conducive to project scale-up.

[0073] 3) The above technical solution catalyzes the reaction of acetylene and hydrogen chloride in the solution in a pipeline reactor to synthesize vinyl chloride. It has a large dissolving capacity for vinyl chloride and can make the acetylene react more thoroughly. During desorption, hydrogen chloride is introduced at the same time to dissolve and release heat, and the liquid phase catalytic solution will heat up so that the vinyl chloride in the entire solution can be desorbed more thoroughly.

[0074] 4) The vinyl chloride obtained by the above technical solution has high purity, lower acid content, less acetylene concentration, and complete reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0075] Figure 1 This is a schematic diagram of a device for synthesizing vinyl chloride by acetylene hydrochlorination in liquid phase according to the first embodiment of the present invention.

[0076] Reference numerals

[0077] 1 Absorption tower

[0078] 11 First feed port

[0079] 12 Second feed port

[0080] 13. First outlet

[0081] 2 Pipeline Reactor

[0082] 21 Fifth feed port

[0083] 22 Fourth outlet

[0084] 3 Desorption tower

[0085] 31 Third feed port

[0086] 32 Fourth feed port

[0087] 33 Second outlet

[0088] 34 The third outlet DETAILED DESCRIPTION

[0089] The present invention is further described below in conjunction with examples. It should be understood that these examples are only used to illustrate the present invention, but not to limit the scope of the present invention. The experimental methods and reagents without specific conditions in the following examples are all carried out or configured according to conventional conditions or conditions recommended by the manufacturer.

[0090] like Figure 1 As shown, a device for synthesizing vinyl chloride by acetylene hydrochlorination in liquid phase comprises an absorption tower 1, a pipeline reactor 2 and a desorption tower 3; the desorption tower 1 is provided with a first feed inlet 11 for introducing a liquid phase catalytic solution containing hydrogen chloride, a second feed inlet 12 for introducing acetylene and a first discharge port 13 for discharging the catalytic solution absorbed acetylene; the desorption tower 3 is provided with a third feed inlet 31 for introducing a reaction solution, a fourth feed inlet 32 ​​for introducing hydrogen chloride gas, a second discharge port 33 for discharging crude vinyl chloride and a third discharge port 34 for discharging a liquid phase catalytic solution containing hydrogen chloride;

[0091] The first discharge port 13 is connected to the third feed port 31 via the pipeline reactor 2;

[0092] The third discharge port 34 is connected to the first feed port 11 .

[0093] Specifically, the first feed port 11 can be arranged at the top of the absorption tower 1. The second feed port 12 can be arranged at the bottom of the absorption tower 1. The first discharge port 13 can be arranged at the bottom of the absorption tower 1. The third feed port 31 can be arranged at the top of the desorption tower 3. The fourth feed port 32 can be arranged at the bottom of the desorption tower 3. The second discharge port 33 can be arranged at the top of the desorption tower 3. The third discharge port 34 can be arranged at the bottom of the desorption tower 3.

[0094] Furthermore, the pipeline reactor 2 is provided with a heat source channel, and the third discharge port 34 is connected to the first feed port 11 via the heat source channel.

[0095] Specifically, the pipeline reactor 2 is provided with a fifth feed port 21 for introducing a catalytic solution for absorbing acetylene and a fourth discharge port 22 for discharging the reaction solution. The fifth feed port 21 is connected to the first discharge port 13 , and the fourth discharge port 22 is connected to the third feed port 31 .

[0096] The method for using the above device comprises the following steps:

[0097] 1) A liquid-phase catalytic solution containing hydrogen chloride and acetylene are introduced into an absorption tower 1 through a first feed port 11 and a second feed port 12, respectively, and the liquid-phase catalytic solution containing hydrogen chloride absorbs acetylene to saturation to obtain a catalytic solution absorbing acetylene, and the catalytic solution absorbing acetylene is discharged through a first discharge port 13;

[0098] 2) the catalytic solution absorbing acetylene is introduced into the pipeline reactor 2, and the acetylene in the catalytic solution reacts with hydrogen chloride to synthesize vinyl chloride under the temperature and pressure of the acetylene hydrochlorination reaction to obtain a reaction solution;

[0099] 3) The reaction solution and hydrogen chloride are introduced into the desorption tower 3 through the third feed port 31 and the fourth feed port 32, respectively, the reaction solution is desorbed, and hydrogen chloride is introduced to dissolve, so as to obtain crude vinyl chloride and a liquid-phase catalytic solution containing hydrogen chloride, respectively; the crude vinyl chloride is discharged through the second discharge port 33, and the liquid-phase catalytic solution containing hydrogen chloride is discharged through the third discharge port 34 and refluxed to the absorption tower 1 through the first feed port 11 to continue to absorb acetylene.

[0100] Example 1

[0101] Preparation of catalytic solution: Take 100g N,N-dimethylformamide and 1900g N-methylimidazole and mix them evenly to prepare a liquid catalytic solution.

[0102] 120 g of hydrogen chloride was introduced into the prepared liquid catalytic solution, and the liquid catalytic solution containing hydrogen chloride was introduced from the top of the absorption tower. At the same time, 85 g of acetylene was introduced from the bottom of the absorption tower. The temperature for absorbing acetylene was 50° C., and the amount of acetylene absorbed accounted for 4.0% of the mass of the liquid catalytic solution containing hydrogen chloride.

[0103] The catalytic solution that has absorbed acetylene is pumped into the pipeline reactor, the reaction temperature is controlled to be 160°C, the reaction pressure is 3.0MPa, when the acetylene conversion rate in the pipeline reactor reaches 98%, the reaction solution is input into the desorption tower from the top of the desorption tower, the temperature of the desorption tower is controlled to be 170°C, normal pressure, and 202g of crude vinyl chloride is produced at the top of the desorption tower. The resolved catalytic solution absorbs 120g of hydrogen chloride and returns to the absorption tower to continue absorbing acetylene. The crude vinyl chloride gas component analysis is shown in Table 1.

[0104] Example 2

[0105] Preparation of catalytic solution: 390 g of N, N-dimethylacetamide, 1500 g of N-ethylimidazole and 10 g of palladium chloride were mixed evenly to prepare a liquid catalytic solution.

[0106] 320 g of hydrogen chloride was introduced into the prepared liquid catalytic solution, and the liquid catalytic solution containing hydrogen chloride was introduced into the top of the absorption tower. At the same time, 228 g of acetylene was introduced from the bottom of the absorption tower. The temperature for absorbing acetylene was -30°C, and the amount of acetylene absorbed accounted for 10.3% of the mass of the liquid catalytic solution containing hydrogen chloride.

[0107] The catalytic solution that has absorbed acetylene is pumped into the pipeline reactor, the reaction temperature is controlled to be 80°C, the reaction pressure is 0.05MPa, when the acetylene conversion rate in the pipeline reactor reaches 97%, the reaction solution is input into the desorption tower from the top of the desorption tower, the temperature of the desorption tower is controlled to be 100°C, 0.05MPa, and 540g of crude vinyl chloride is produced at the top of the desorption tower. The resolved catalytic solution absorbs 320g of hydrogen chloride again and returns to the absorption tower to continue absorbing acetylene. The crude vinyl chloride gas component analysis is shown in Table 1.

[0108] Example 3

[0109] Preparation of catalytic solution: 500 g of N-methylpyrrolidone, 200 g of 1-methyl-3-ethylimidazole chloride and 300 g of cuprous chloride are mixed evenly to prepare a liquid catalytic solution.

[0110] 130 g of hydrogen chloride was introduced into the prepared liquid catalytic solution, and the liquid catalytic solution containing hydrogen chloride was introduced from the top of the absorption tower. At the same time, 92 g of acetylene was introduced from the bottom of the absorption tower. The temperature for absorbing acetylene was -10°C, and the amount of acetylene absorbed accounted for 8.1% of the mass of the liquid catalytic solution containing hydrogen chloride.

[0111] The catalytic solution that has absorbed acetylene is pumped into the pipeline reactor, and the reaction temperature is controlled to be 110°C and the reaction pressure is 1.2MPa. When the acetylene conversion rate in the pipeline reactor reaches 95%, the reaction solution is input into the desorption tower from the top of the desorption tower, and the temperature of the desorption tower is controlled to be 130°C and 0.3MPa. 217g of vinyl chloride is produced at the top of the desorption tower. The resolved catalytic solution absorbs 130g of hydrogen chloride and returns to the absorption tower to continue absorbing acetylene. The crude vinyl chloride gas component analysis is shown in Table 1.

[0112] Example 4

[0113] Preparation of catalytic solution: 1300g N-methylpyrrolidone, 500g 1-methyl-3-ethylimidazole chloride and 200g N-ethylimidazole are mixed evenly to prepare a liquid catalytic solution.

[0114] 300 g of hydrogen chloride was introduced into the prepared liquid catalytic solution, and the liquid catalytic solution containing hydrogen chloride was introduced from the top of the absorption tower. At the same time, 241 g of acetylene was introduced from the bottom of the absorption tower. The temperature for absorbing acetylene was 0° C., and the amount of acetylene absorbed accounted for 10.4% of the mass of the liquid catalytic solution containing hydrogen chloride.

[0115] The catalytic solution that has absorbed acetylene is pumped into the pipeline reactor, and the reaction temperature is controlled to be 150°C and the reaction pressure is 2.5MPa. When the acetylene conversion rate in the pipeline reactor reaches 98%, the reaction solution is input into the desorption tower from the top of the desorption tower, and the temperature of the desorption tower is controlled to be 160°C and 0.5MPa. 509g of vinyl chloride is produced at the top of the desorption tower. The resolved catalytic solution absorbs 300g of hydrogen chloride and returns to the absorption tower to continue absorbing acetylene. The crude vinyl chloride gas component analysis is shown in Table 1.

[0116] Example 5

[0117] Preparation of catalytic solution: 800 g of N-cyclohexylpyrrolidone and 42 g of 1-methyl-3-butylimidazole chloride were mixed evenly to prepare a liquid-phase catalytic solution.

[0118] 80 g of hydrogen chloride was introduced into the prepared liquid catalytic solution, and the liquid catalytic solution containing hydrogen chloride was introduced from the top of the absorption tower. At the same time, 57 g of acetylene was introduced from the bottom of the absorption tower. The temperature for absorbing acetylene was 20° C., and the amount of acetylene absorbed accounted for 6.2% of the mass of the liquid catalytic solution containing hydrogen chloride.

[0119] The catalytic solution that has absorbed acetylene is pumped into the pipeline reactor, and the reaction temperature is controlled to be 140°C and the reaction pressure is 1.0MPa. When the acetylene conversion rate in the pipeline reactor reaches 97%, the reaction solution is input into the desorption tower from the top of the desorption tower, and the temperature of the desorption tower is controlled to be 150°C and 0.3MPa. 135g of vinyl chloride is produced at the top of the desorption tower. The resolved catalytic solution absorbs 80g of hydrogen chloride again and returns to the absorption tower to continue absorbing acetylene. The crude vinyl chloride gas component analysis is shown in Table 1.

[0120] Example 6

[0121] Preparation of catalytic solution: 450 g of N-methylpyrrolidone, 750 g of N-methylimidazole and 300 g of cupric chloride were mixed evenly to prepare a liquid catalytic solution.

[0122] 210 g of hydrogen chloride was introduced into the prepared liquid catalytic solution, and the liquid catalytic solution containing hydrogen chloride was introduced from the top of the absorption tower. At the same time, 150 g of acetylene was introduced from the bottom of the absorption tower. The temperature for absorbing acetylene was 10° C., and the amount of acetylene absorbed accounted for 8.7% of the mass of the liquid catalytic solution containing hydrogen chloride.

[0123] The catalytic solution that has absorbed acetylene is pumped into the pipeline reactor, the reaction temperature is controlled to be 160°C, and the reaction pressure is 3.0MPa. When the acetylene conversion rate in the pipeline reactor reaches 98.5%, the reaction solution is input into the desorption tower from the top of the desorption tower, and the temperature of the desorption tower is controlled to be 170°C and 0.5MPa. 358g of vinyl chloride is produced at the top of the desorption tower. The resolved catalytic solution absorbs 210g of hydrogen chloride and returns to the absorption tower to continue absorbing acetylene. The crude vinyl chloride gas component analysis is shown in Table 1.

[0124] Example 7

[0125] Preparation of catalytic solution: 95 g of N, N-dimethylacetamide, 1200 g of N-cyclohexylimidazole, 595 g of 1-butyl-3-methylimidazole chloride and 10 g of gold chloride are mixed evenly to prepare a liquid catalytic solution.

[0126] 120 g of hydrogen chloride was introduced into the prepared liquid catalytic solution, and the liquid catalytic solution containing hydrogen chloride was introduced into the top of the absorption tower. At the same time, 85 g of acetylene was introduced from the bottom of the absorption tower. The temperature for absorbing acetylene was 30° C., and the amount of acetylene absorbed accounted for 4.2% of the mass of the liquid catalytic solution containing hydrogen chloride.

[0127] The catalytic solution that has absorbed acetylene is pumped into the pipeline reactor, the reaction temperature is controlled to be 120°C, and the reaction pressure is 0.5MPa. When the acetylene conversion rate in the pipeline reactor reaches 96.5%, the reaction solution is input into the desorption tower from the top of the desorption tower, and the temperature of the desorption tower is controlled to be 130°C and 0.1MPa. 200g of crude vinyl chloride is produced at the top of the desorption tower. The resolved catalytic solution absorbs 120g of hydrogen chloride and returns to the absorption tower to continue absorbing acetylene. The crude vinyl chloride gas component analysis is shown in Table 1.

[0128] Example 8

[0129] Preparation of catalytic solution: 1490 g of N-cyclohexylpyrrolidone, 80 g of 1-hexyl-3-methylimidazolium chloride and 8 g of platinum chloride were mixed evenly to prepare a liquid catalytic solution.

[0130] 126 g of hydrogen chloride was introduced into the prepared liquid catalytic solution, and the liquid catalytic solution containing hydrogen chloride was introduced into the top of the absorption tower. At the same time, 90 g of acetylene was introduced from the bottom of the absorption tower. The temperature for absorbing acetylene was 0° C., and the amount of acetylene absorbed accounted for 5.3% of the mass of the liquid catalytic solution containing hydrogen chloride.

[0131] The catalytic solution that has absorbed acetylene is pumped into the pipeline reactor, and the reaction temperature is controlled to be 130°C and the reaction pressure is 0.5MPa. When the acetylene conversion rate in the pipeline reactor reaches 97%, the reaction solution is input into the desorption tower from the top of the desorption tower, and the temperature of the desorption tower is controlled to be 140°C and 0.3MPa. 212g of crude vinyl chloride is produced at the top of the desorption tower. The resolved catalytic solution absorbs 126g of hydrogen chloride and returns to the absorption tower to continue absorbing acetylene. The crude vinyl chloride gas component analysis is shown in Table 1.

[0132] Comparative Example

[0133] Preparation of catalytic solution: 450 g of N-methylpyrrolidone, 750 g of N-methylimidazole and 300 g of cupric chloride were mixed evenly to prepare a liquid catalytic solution.

[0134] 210 g of hydrogen chloride was introduced into the prepared liquid catalytic solution, and the liquid catalytic solution containing hydrogen chloride was introduced from the top of the absorption tower. At the same time, 150 g of acetylene was introduced from the bottom of the absorption tower. The temperature for absorbing acetylene was 10° C., and the amount of acetylene absorbed accounted for 8.7% of the mass of the liquid catalytic solution containing hydrogen chloride.

[0135] The catalytic solution that has absorbed acetylene is sealed in the absorption tower, and the reaction temperature in the tower is controlled to be 160°C and the reaction pressure is 3.0 MPa. When the acetylene conversion rate in the absorption tower is stable, 345 g of crude vinyl chloride is extracted from the top of the tower. The crude vinyl chloride gas component analysis is shown in Table 1.

[0136] The pressures mentioned in the above embodiments and comparative examples are all gauge pressures.

[0137] Table 1 Analysis of crude vinyl chloride gas components

[0138] Components Vinyl chloride / % Acetylene / % Hydrogen chloride / % Example 1 98 1.9 0.04 Example 2 97 3 0.001 Example 3 95 5 0.01 Example 4 98 1.9 0.03 Example 5 97 3 0.06 Example 6 98.5 1.5 0.002 Example 7 96.5 3.4 0.08 Example 8 97 2.9 0.05 Comparative Example 92 6.4 1.6

[0139] The above examples are for the purpose of illustrating the embodiments disclosed by the present invention and are not to be construed as limitations of the present invention. In addition, the various modifications listed herein and the variations of methods and compositions in the invention are obvious to those skilled in the art without departing from the scope and spirit of the present invention. Although the present invention has been specifically described in conjunction with various specific preferred embodiments of the present invention, it should be understood that the present invention should not be limited to these specific embodiments. In fact, various modifications obvious to those skilled in the art as described above to obtain the invention should be included within the scope of the present invention.

Claims

1. A method for synthesizing vinyl chloride by hydrochlorination of acetylene in liquid phase, characterized in that: The steps include: 1) Acetylene is introduced into a liquid catalytic solution containing hydrogen chloride, and the liquid catalytic solution containing hydrogen chloride absorbs acetylene until saturation, thereby obtaining a catalytic solution absorbing acetylene; the solubility of the liquid catalytic solution for acetylene at room temperature and pressure is ≥2%, and the solubility of the liquid catalytic solution for hydrogen chloride at 100-160°C is >5%, and the liquid catalytic solution has a catalytic effect on the synthesis of vinyl chloride by acetylene hydrochlorination; the liquid catalytic solution is a liquid non-metallic catalytic solution and / or a liquid metal catalytic solution; The liquid non-metallic catalytic solution comprises a first component and a second component, the first component is selected from at least one of an imidazole compound and an imidazole chloride salt, and the second component is an amide solvent; The liquid metal catalytic solution comprises at least one selected from the first component and the second component and a third component, wherein the third component is a metal chloride; 2) subjecting the catalytic solution to the temperature and pressure of acetylene hydrochlorination reaction to react acetylene and hydrogen chloride in the catalytic solution to synthesize vinyl chloride, thereby obtaining a reaction solution; 3) desorbing the reaction solution and introducing hydrogen chloride to dissolve it, thereby obtaining crude vinyl chloride and a liquid catalytic solution containing hydrogen chloride; The liquid phase catalytic solution containing hydrogen chloride is refluxed to step 1) to continue absorbing acetylene.

2. The method for synthesizing vinyl chloride by liquid phase hydrochlorination of acetylene as claimed in claim 1, characterized in that: The imidazole compound is an imidazole compound in which a C1~C6 alkyl group replaces the hydrogen group in NH; And / or, the imidazolium chloride salt is an N-substituted imidazolium salt, and the substituent is a C1~C6 alkyl group; And / or, the amide solvent is an amide compound in which a hydrogen group in NH is substituted by a C1-C6 alkyl group; And / or, the metal chloride is selected from at least one of cupric chloride, cuprous chloride, gold chloride, palladium chloride, platinum chloride, ruthenium chloride and iridium chloride; And / or, in the liquid non-metallic catalytic solution, the mass percentage of the first component is 5 to 95%, and the mass percentage of the second component is 5 to 95%; And / or, in the liquid metal catalytic solution, the mass percentage of the first component is 5 to 94.5%, the mass percentage of the second component is 5 to 94.5%, and the mass percentage of the third component is 0.5 to 30%.

3. The method for synthesizing vinyl chloride by liquid phase hydrochlorination of acetylene as claimed in claim 2, characterized in that: The imidazole compound is selected from at least one of N-methylimidazole, N-ethylimidazole, N-propylimidazole, N-butylimidazole, N-cyclohexylimidazole, N-isopropylimidazole and N-isobutylimidazole.

4. The method for synthesizing vinyl chloride by liquid phase hydrochlorination of acetylene as claimed in claim 2, characterized in that: The imidazolium chloride salt is selected from at least one of 1-methyl-3-ethylimidazolium chloride, 1-ethyl-3-methylimidazolium chloride, 1-methyl-3-butylimidazolium chloride, 1-ethyl-3-ethylimidazolium chloride, 1-butyl-3-methylimidazolium chloride, 1,3-dimethylimidazolium chloride, 1,3-diisopropylimidazolium chloride and 1-hexyl-3-methylimidazolium chloride.

5. The method for synthesizing vinyl chloride by liquid phase hydrochlorination of acetylene as claimed in claim 2, characterized in that: The amide solvent is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N-methylpyrrolidone, N-propylpyrrolidone, N-isopropylpyrrolidone, N-cyclohexylpyrrolidone and N-ethylpyrrolidone.

6. The method for synthesizing vinyl chloride by liquid phase hydrochlorination of acetylene as claimed in claim 1, characterized in that: It also includes at least one of the following technical features: 11) In step 1), the amount of acetylene absorbed is greater than 2wt% of the mass of the liquid catalytic solution containing hydrogen chloride; 12) In step 1), the temperature of absorbing acetylene is -30 ~ 50 °C; 21) In step 2), the temperature of the acetylene hydrochlorination reaction is 80-160°C; 22) In step 2), the pressure of the acetylene hydrochlorination reaction is 0.05-3.0 MPa; 23) In step 2), the acetylene conversion rate in the synthesis of vinyl chloride by the reaction of acetylene and hydrogen chloride is above 95%; 31) In step 3), the desorption temperature is 100-170°C; 32) In step 3), the desorption pressure is 0-0.5 MPa; 33) In step 3), the molar ratio of the amount of hydrogen chloride introduced to the amount of acetylene introduced in step 1) is 1:1; 34) The liquid catalytic solution containing hydrogen chloride obtained in step 3) is heat exchanged with the catalytic solution in step 2) and then refluxed to step 1) to continue absorbing acetylene.

7. A device for synthesizing vinyl chloride by acetylene hydrochlorination in liquid phase, characterized in that: The invention comprises an absorption tower (1), a pipeline reactor (2) and a desorption tower (3); the desorption tower (1) is provided with a first feed inlet (11) for introducing a liquid-phase catalytic solution containing hydrogen chloride, a second feed inlet (12) for introducing acetylene and a first discharge port (13) for discharging the catalytic solution absorbed by acetylene; the desorption tower (3) is provided with a third feed inlet (31) for introducing a reaction solution, a fourth feed inlet (32) for introducing hydrogen chloride gas, a second discharge port (33) for discharging crude vinyl chloride and a third discharge port (34) for discharging the liquid-phase catalytic solution containing hydrogen chloride; The first discharge port (13) is connected to the third feed port (31) via the pipeline reactor (2); The third discharge port (34) is connected to the first feed port (11).

8. The device for synthesizing vinyl chloride by liquid phase acetylene hydrochlorination as claimed in claim 7, characterized in that: The first feed inlet (11) is arranged at the top of the absorption tower (1); And / or, the second feed inlet (12) is arranged at the bottom of the absorption tower (1); And / or, the first discharge port (13) is arranged at the bottom of the absorption tower (1); And / or, the third feed port (31) is arranged at the top of the desorption tower (3); And / or, the fourth feed port (32) is arranged at the bottom of the desorption tower (3); And / or, the second discharge port (33) is arranged at the top of the desorption tower (3); And / or, the third discharge port (34) is arranged at the bottom of the desorption tower (3); And / or, the pipeline reactor (2) is provided with a fifth feed port (21) for introducing a catalytic solution for absorbing acetylene and a fourth discharge port (22) for discharging the reaction solution, the fifth feed port (21) being connected to the first discharge port (13), and the fourth discharge port (22) being connected to the third feed port (31); And / or, the pipeline reactor (2) is provided with a heat source channel, and the third discharge port (34) is connected to the first feed port (11) via the heat source channel.

9. The method for using the device according to claim 7 or 8, characterized in that: The steps include: 1) introducing a liquid-phase catalytic solution containing hydrogen chloride and acetylene into the absorption tower (1) through the first feed port (11) and the second feed port (12), respectively, the liquid-phase catalytic solution containing hydrogen chloride absorbs acetylene to saturation, thereby obtaining a catalytic solution for absorbing acetylene, and the catalytic solution for absorbing acetylene is discharged through the first discharge port (13); The catalytic solution for absorbing acetylene is introduced into the pipeline reactor (2), and the catalytic solution is subjected to the temperature and pressure of the acetylene hydrochlorination reaction, so that acetylene and hydrogen chloride in the catalytic solution react to synthesize vinyl chloride, thereby obtaining a reaction solution; The reaction solution and hydrogen chloride are introduced into the desorption tower (3) through the third feed port (31) and the fourth feed port (32), respectively, the reaction solution is desorbed, and hydrogen chloride is introduced to dissolve, thereby obtaining crude vinyl chloride and a liquid catalytic solution containing hydrogen chloride, respectively; The crude vinyl chloride is discharged through the second discharge port (33), and the liquid-phase catalytic solution containing hydrogen chloride is discharged through the third discharge port (34) and refluxed into the absorption tower (1) through the first feed port (11) to continue absorbing acetylene.

10. The method of use according to claim 9, characterized in that: It also includes at least one of the following technical features: 11) In step 1), the amount of acetylene absorbed in the absorption tower (1) is greater than 2 wt% of the mass of the liquid catalytic solution containing hydrogen chloride; 12) In step 1), the temperature of absorbing acetylene in the absorption tower (1) is -30 to 50°C; 13) In step 1), the liquid catalytic solution is the liquid catalytic solution according to any one of claims 1 to 3; 21) In step 2), the temperature of the acetylene hydrochlorination reaction in the pipeline reactor (2) is 80-160°C; 22) The pressure of the acetylene hydrochlorination reaction in the pipeline reactor (2) is 0.05~3.0MPa; 23) In step 2), the acetylene conversion rate in the synthesis of vinyl chloride by the reaction of acetylene and hydrogen chloride is above 95%; 31) In step 3), the desorption temperature in the desorption tower (3) is 100-170°C; 32) The desorption pressure in the desorption tower (3) is 0-0.5 MPa; 33) In step 3), the molar ratio of the amount of hydrogen chloride introduced into the desorption tower (3) to the amount of acetylene introduced into the absorption tower (1) is 1:1; 34) In step 3), the liquid catalytic solution containing hydrogen chloride is discharged through the third discharge port (34) and sequentially flows back to the absorption tower (1) through the heat source channel of the pipeline reactor (2) and the first feed port (11) to continue absorbing acetylene.

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