Liquid phase method methanol synthesis system based on reactive distillation coupled pervaporation

Abstract

The invention provides a liquid phase method methanol synthesis system based on reactive distillation coupled pervaporation, which comprises the following steps: mixing hydrogen and carbon dioxide into a raw material gas stream, passing through a multi-stage compressor and then passing through a first heat exchanger to obtain a pretreated raw material gas stream; the solvent stream passes through a booster pump and then passes through a second heat exchanger to obtain a pretreated solvent stream, the pretreated raw material gas stream and the pretreated solvent stream enter a reactive distillation tower and are divided into an unreacted circulating gas stream and a mixed stream through a gas-liquid separator, and the mixed stream passes through a methanol distillation tower to obtain a refined methanol product; and the unreacted recycle gas stream and the tower bottom stream of the reactive distillation tower are recycled. According to the method, the solvent is adopted to strengthen the reaction of synthesizing methanol through carbon dioxide hydrogenation, the concentration of the product on the surface of the catalyst is reduced by utilizing the excellent solubility of the solvent to the product, the reaction moves towards the methanol generation direction, the conversion per pass of carbon dioxide is high, the gas circulation amount is low, and the methanol yield is high.

Description

Technical Field

[0001] The invention belongs to the technical field of methanol synthesis, and in particular relates to a liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation. Background Art

[0002] Methanol (CH3OH), as an important chemical raw material, is widely used in the fields of energy, chemical industry and medicine. The traditional methanol synthesis process mainly relies on fossil energy such as natural gas or coal. However, these processes not only consume a lot of energy, but also release greenhouse gases such as carbon dioxide, causing environmental pollution. Therefore, the technical route of producing methanol from carbon dioxide hydrogenation can not only reduce greenhouse gas emissions and realize the resource utilization of CO2, but also connect with the new energy electrolysis water hydrogen production industry to realize the storage of hydrogen energy, and also provide a low-carbon, environmentally friendly, efficient and feasible technical route for the methanol synthesis process.

[0003] At present, the synthesis of methanol from carbon dioxide hydrogenation is mainly a gas-phase process, which faces the challenge of thermodynamic equilibrium limitations in practical applications. It is difficult to significantly improve the CO2 conversion rate, and the selectivity of methanol on the currently developed catalysts needs to be further improved. Therefore, during the reaction process, in order to avoid the waste of raw gas, a large amount of unreacted gas needs to be circulated in the system, which leads to an increase in the energy consumption of the reaction process, thereby increasing the production cost of methanol.

[0004] Based on this, a liquid-phase methanol synthesis system based on reactive distillation coupled with pervaporation was proposed. The solvent was introduced into the reaction process, and the good solubility of the solvent in the product was used to overcome the limitations of thermodynamic equilibrium. This can significantly improve the single-pass conversion rate of carbon dioxide, reduce the gas circulation volume of the reaction system, increase the methanol yield, and reduce the process energy consumption. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation in view of the deficiencies of the above-mentioned prior art, so as to solve the problems raised in the above-mentioned background technology.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation, comprising the following steps:

[0007] S1, pretreatment part, hydrogen and carbon dioxide are mixed into a raw gas stream, which passes through a multi-stage compressor and then passes through a first heat exchanger to obtain a pretreated raw gas stream; the solvent stream passes through a booster pump and then passes through a second heat exchanger to obtain a pretreated solvent stream;

[0008] S2, methanol synthesis part, the pre-treated raw material gas stream enters from the bottom of the reaction distillation tower, the pre-treated solvent stream enters from the top of the reaction distillation tower, and reacts to generate methanol and water. The unreacted gas, part of the methanol and part of the water in the reaction distillation tower flow out from the top of the reaction distillation tower and are separated into two parts by a gas-liquid separator, one part is the unreacted circulating gas stream, and the other is the mixed stream of methanol and water. The remaining part in the reaction distillation tower flows out from the bottom of the reaction distillation tower to obtain the bottom stream;

[0009] S3, methanol refining part, the mixed stream enters the methanol refining system, is first decompressed by the pressure reducing valve, and then preheated by the heat exchanger, and then enters the flash tank. After the non-condensable steam is relaxed, the rest of the flash tank enters the methanol distillation tower, and the refined methanol product is obtained by the methanol distillation tower;

[0010] S4, the circulation part, the unreacted circulating gas stream in S2 is circulated back to the pre-treatment part, mixed with the raw gas stream and then recycled; the bottom stream of the reaction distillation tower in S2 enters the pervaporation solvent recovery device, and the high-purity solvent stream is separated by the pervaporation solvent recovery device, and the high-purity solvent stream is circulated back to the pretreatment part, mixed with the solvent stream for recycling.

[0011] As a further illustration of the present invention, the molar ratio of hydrogen to carbon dioxide in the raw gas stream in S1 is 2 to 3.5, the pressure is 4.5 to 10.0 MPa, and the temperature is 220°C to 300°C.

[0012] As a further illustration of the present invention, the solvent in the solvent stream is a polar solvent, a non-polar solvent or a mineral oil solvent.

[0013] As a further illustration of the present invention, the polar solvents are tetraethylene glycol dimethyl ether, dimethylformamide and dimethylacetamide, the non-polar solvents are squalane, n-octane, decalin, tetralin and n-dodecane, and the mineral oil solvents are Freezene-100, Witco-40, Drakeol-7 and Multitherm-PGI.

[0014] As a further illustration of the present invention, the molar ratio of the solvent in the solvent stream in S1 to the molar ratio of the feed gas is 0.6 to 1, the pressure is 4.5 to 10.0 MPa, and the temperature is 220° C. to 300° C.

[0015] As a further illustration of the present invention, the methanol synthesis catalyst in the reaction distillation tower 5 in S2 is a copper-based catalyst, the synthesis pressure in the reaction distillation tower 5 is 4.5-10.0 MPa, the temperature is 220° C.-300° C., and the reflux ratio of the reaction distillation tower 5 is 1.0-1.8.

[0016] As a further illustration of the present invention, the pressure of the methanol distillation tower 9 in S3 is 0.1-0.5 MPa, the temperature is 30° C.-60° C., and the reflux ratio of the methanol distillation tower 9 is 0.2-0.3.

[0017] As a further illustration of the present invention, the circulating feed ratio of the unreacted circulating gas stream in S4 is 0.02 to 0.08.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The present invention realizes the synthesis of methanol by hydrogenation of carbon dioxide in a solvent, with mild reaction conditions, short process, fewer control nodes and simpler operation.

[0020] 2. The present invention proposes to use a solvent to strengthen the carbon dioxide hydrogenation to methanol reaction, and utilizes the excellent solubility of the solvent in the product to reduce the product concentration on the catalyst surface, so that the reaction moves toward the direction of methanol production. The single-pass conversion rate of carbon dioxide is high, the gas circulation volume is low, and the methanol yield is high.

[0021] 3. The reactive distillation technology of the present invention performs synthesis and separation simultaneously in one device, and utilizes the reaction heat for product separation. The products or intermediates generated by the reaction are separated in time, which can improve the yield of the product, reduce the equipment cost, and achieve the purpose of energy saving, and effectively reduce the difficulty and energy consumption of separation of solvent and water. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall system of the present invention.

[0023] Figure 2 Schematic diagram showing the effect of the molar amount of the polar solvent tetraethylene glycol dimethyl ether on the reaction of hydrogenating carbon dioxide to produce methanol in Example 1 of the present invention;

[0024] Figure 3 Schematic diagram showing the effect of the molar amount of the mineral oil solvent Multitherm-PGI on the reaction of hydrogenating carbon dioxide to produce methanol in Example 1 of the present invention;

[0025] Figure 4 This is a schematic diagram showing the effect of the molar amount of the non-polar solvent squalane on the reaction of hydrogenating carbon dioxide to produce methanol in Example 1 of the present invention.

[0026] Description of reference numerals:

[0027] 1-multi-stage compressor; 2-first heat exchanger; 3-boosting pump; 4-second heat exchanger; 5-reaction distillation tower; 6-pressure reducing valve; 7-heat exchanger; 8-flash tank; 9-methanol distillation tower; 10-permeation vaporization solvent recovery device; 11-gas-liquid separator. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1, as Figure 1 As shown, the present invention provides a technical solution: a liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation, comprising the following steps:

[0030] S1, pretreatment part, hydrogen and carbon dioxide are mixed into a raw gas stream, which passes through a multi-stage compressor 1 and then passes through a first heat exchanger 2 to obtain a pretreated raw gas stream; the solvent stream passes through a booster pump 3 and then passes through a second heat exchanger 4 to obtain a pretreated solvent stream;

[0031] The carbon dioxide concentration is 99.9%, the temperature is 40°C, the pressure is 0.1MPa, and the molar flow rate is 401kmol / h.

[0032] The purity of the hydrogen raw material is 99.9%, the temperature is 40°C, the pressure is 0.1MPa, and the molar flow rate is 1189kmol / h.

[0033] The molar ratio of hydrogen to carbon dioxide in the raw gas stream is 2.96, the pressure is 4 MPa, and the temperature is 240°C.

[0034] The solvent in the solvent stream is a polar solvent, a non-polar solvent or a mineral oil solvent, the polar solvent is tetraethylene glycol dimethyl ether, dimethylformamide or dimethylacetamide, the non-polar solvent is squalane, n-octane, decalin, tetralin or n-dodecane, and the mineral oil solvent is Freezene-100, Witco-40, Drakeol-7 or Multitherm-PGI.

[0035] The effect of the molar amount of the polar solvent tetraethylene glycol dimethyl ether on the reaction of carbon dioxide hydrogenation to produce methanol is as follows: Figure 2 As shown; experimental conditions: temperature 250°C, pressure 5Mpa, feed hydrogen 3kmol / h, carbon dioxide 1kmol / h.

[0036] Figure 2 The results showed that the carbon dioxide conversion rate reached 85.11%, the methanol yield reached 82.98%, the methanol selectivity was 98.18%, and the carbon monoxide selectivity was 1.82%.

[0037] Effect of the molar amount of mineral oil solvent Multitherm-PGI on the reaction of carbon dioxide hydrogenation to methanol Figure 3 As shown, the experimental conditions are: temperature 250°C, pressure 5 MPa, feed hydrogen 3 kmol / h, and carbon dioxide 1 kmol / h.

[0038] Figure 3 The results show that the carbon dioxide conversion rate reaches 69.38%, the methanol yield reaches 67.16%, the methanol selectivity is 96.81%, and the carbon monoxide selectivity is 3.20%.

[0039] Effect of the molar amount of non-polar solvent squalane on the reaction of carbon dioxide hydrogenation to methanol Figure 4 As shown, the experimental conditions are: temperature 250°C, pressure 5 MPa, feed hydrogen 3 kmol / h, and carbon dioxide 1 kmol / h.

[0040] Figure 4 The results showed that the carbon dioxide conversion rate reached 50.77%, the methanol yield reached 47.66%, the methanol selectivity was 93.86%, and the carbon monoxide selectivity was 6.14%.

[0041] In this embodiment, the solvent is tetraethylene glycol dimethyl ether, the molar ratio of the solvent to the raw gas is 0.62, the pressure is 4Mpa, and the temperature is 240°C;

[0042] S2, methanol synthesis part, the pre-treated raw material gas stream enters from the bottom of the reaction distillation tower 5, the pre-treated solvent stream enters from the top of the reaction distillation tower 5, and reacts to generate methanol and water. The unreacted gas, part of the methanol and part of the water in the reaction distillation tower 5 flow out from the top of the reaction distillation tower 5 and are separated into two parts by the gas-liquid separator 11, one part is the unreacted circulating gas stream, and the other is the mixed stream of methanol and water. The remaining part in the reaction distillation tower 5 flows out from the bottom of the reaction distillation tower 5 to obtain the bottom stream;

[0043] The reactive distillation tower 5 has 50 plates, a reflux ratio of 1.9, a distillate feed ratio of 0.27, a synthesis pressure of 4 MPa, and a methanol synthesis catalyst is a copper-based catalyst.

[0044] S3, methanol refining part, the mixed stream enters the methanol refining system, is first decompressed by the pressure reducing valve 6, and then preheated by the heat exchanger 7, and then enters the flash tank 8. After the non-condensable steam is relaxed, the rest of the flash tank 8 enters the methanol distillation tower 9, and the refined methanol product is obtained by the methanol distillation tower 9;

[0045] Among them, the preheating temperature is 65°C, the pressure is 0.15Mpa, the number of plates of methanol distillation tower 9 is 17, the reflux ratio is 0.92, the distillate feed ratio is 0.95, and the pressure is 0.1Mpa.

[0046] S4, the circulation part, the unreacted circulating gas stream in S2 is circulated back to the pretreatment part, mixed with the raw gas stream and then recycled; the bottom stream of the reaction distillation tower 5 in S2 enters the pervaporation solvent recovery device 10, and the high-purity solvent stream is separated by the pervaporation solvent recovery device 10, and the high-purity solvent stream is circulated back to the pretreatment part, mixed with the solvent stream for recycling.

[0047] The raw gas circulation feed ratio is 0.05; the solvent circulation feed ratio is 999.

[0048] The process material data is shown in Table 1:

[0049] Table 1

[0050]

[0051] The results show that the methanol output of this process is 100.18kt / y, the purity is 99.90%, the single-pass conversion rate of carbon dioxide is 94.89%, and the carbon dioxide utilization rate is 93.61%.

[0052] Example 2, the present invention provides a technical solution: a liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation, comprising the following steps:

[0053] S1, pretreatment part, hydrogen and carbon dioxide are mixed into a raw gas stream, which passes through a multi-stage compressor 1 and then passes through a first heat exchanger 2 to obtain a pretreated raw gas stream; the solvent stream passes through a booster pump 3 and then passes through a second heat exchanger 4 to obtain a pretreated solvent stream;

[0054] The carbon dioxide concentration is 99.9%, the temperature is 40°C, the pressure is 0.1MPa, and the molar flow rate is 401kmol / h.

[0055] The purity of the hydrogen raw material is 99.9%, the temperature is 40°C, the pressure is 0.1MPa, and the molar flow rate is 1189kmol / h.

[0056] The molar ratio of hydrogen to carbon dioxide in the raw gas stream is 2.96, the pressure is 4 MPa, and the temperature is 240°C.

[0057] The carbon dioxide concentration is 99.9%, the temperature is 40°C, the pressure is 0.1MPa, and the molar flow rate is 395kmol / h.

[0058] The purity of the hydrogen raw material is 99.9%, the temperature is 40°C, the pressure is 0.1MPa, and the molar flow rate is 1180kmol / h.

[0059] The molar ratio of hydrogen to carbon dioxide in the raw gas stream is 2.98, the pressure is 5 MPa, and the temperature is 250°C.

[0060] In this embodiment, the solvent is tetraethylene glycol dimethyl ether, the molar ratio of the solvent to the raw gas is 0.8, the pressure is 5 MPa, and the temperature is 250°C;

[0061] S2, methanol synthesis part, the pre-treated raw material gas stream enters from the bottom of the reaction distillation tower 5, the pre-treated solvent stream enters from the top of the reaction distillation tower 5, and reacts to generate methanol and water. The unreacted gas, part of the methanol and part of the water in the reaction distillation tower 5 flow out from the top of the reaction distillation tower 5 and are separated into two parts by the gas-liquid separator 11, one part is the unreacted circulating gas stream, and the other is the mixed stream of methanol and water. The remaining part in the reaction distillation tower 5 flows out from the bottom of the reaction distillation tower 5 to obtain the bottom stream;

[0062] The reactive distillation tower 5 has 60 plates, a reflux ratio of 1.6, a distillate-to-feed ratio of 0.22, a synthesis pressure of 5 MPa, and a methanol synthesis catalyst is a copper-based catalyst.

[0063] S3, methanol refining part, the mixed stream enters the methanol refining system, is first decompressed by the pressure reducing valve 6, and then preheated by the heat exchanger 7, and then enters the flash tank 8. After the non-condensable steam is relaxed, the rest of the flash tank 8 enters the methanol distillation tower 9, and the refined methanol product is obtained by the methanol distillation tower 9;

[0064] Among them, the preheating temperature is 60°C, the pressure is 0.15 MPa, the number of plates of the methanol distillation tower 19 is 16, the reflux ratio is 0.27, the distillate feed ratio is 0.99, and the pressure is 0.1 MPa.

[0065] S4, the circulation part, the unreacted circulating gas stream in S2 is circulated back to the pretreatment part, mixed with the raw gas stream and then recycled;

[0066] The bottom stream of the reaction distillation tower 5 in S2 enters the pervaporation solvent recovery device 10, and a high-purity solvent stream is separated by the pervaporation solvent recovery device 10. The high-purity solvent stream is recycled back to the pretreatment part and mixed with the solvent stream for recycling.

[0067] The raw gas circulation feed ratio is 0.05; the solvent circulation feed ratio is 1319.

[0068] The process material data are shown in Table 2:

[0069] Table 2

[0070]

[0071] The results show that the methanol output of this process is 100.65kt / y with a purity of 99.90%, a single-pass conversion rate of carbon dioxide of 95.31%, and a carbon dioxide utilization rate of 95.19%.

[0072] Example 3, the present invention provides a technical solution: a liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation, comprising the following steps:

[0073] S1, pretreatment part, hydrogen and carbon dioxide are mixed into a raw gas stream, which passes through a multi-stage compressor 1 and then passes through a first heat exchanger 2 to obtain a pretreated raw gas stream; the solvent stream passes through a booster pump 3 and then passes through a second heat exchanger 4 to obtain a pretreated solvent stream;

[0074] The carbon dioxide concentration is 99.9%, the temperature is 40°C, the pressure is 0.1MPa, and the molar flow rate is 391kmol / h;

[0075] The purity of hydrogen raw material is 99.9%, the temperature is 40°C, the pressure is 0.1MPa, and the molar flow rate is 1171kmol / h;

[0076] The molar ratio of hydrogen to carbon dioxide in the raw gas stream is 2.99, the pressure is 6 MPa, and the temperature is 260°C;

[0077] The solvent is tetraethylene glycol dimethyl ether, the molar ratio of the solvent to the raw gas is 0.80, the pressure is 6 MPa, and the temperature is 260°C.

[0078] S2, methanol synthesis part, the pre-treated raw material gas stream enters from the bottom of the reaction distillation tower 5, the pre-treated solvent stream enters from the top of the reaction distillation tower 5, and reacts to generate methanol and water. The unreacted gas, part of the methanol and part of the water in the reaction distillation tower 5 flow out from the top of the reaction distillation tower 5 and are separated into two parts by the gas-liquid separator 11, one part is the unreacted circulating gas stream, and the other is the mixed stream of methanol and water. The remaining part in the reaction distillation tower 5 flows out from the bottom of the reaction distillation tower 5 to obtain the bottom stream;

[0079] The number of plates of the reactive distillation tower 5 is 50, the reflux ratio is 1.9, the distillate feed ratio is 0.27, the synthesis pressure is 6 MPa, and the methanol synthesis catalyst is a copper-based catalyst.

[0080] S3, methanol refining part, the mixed stream enters the methanol refining system, is first decompressed by the pressure reducing valve 6, and then preheated by the heat exchanger 7, and then enters the flash tank 8. After the non-condensable steam is relaxed, the rest of the flash tank 8 enters the methanol distillation tower 9, and the refined methanol product is obtained by the methanol distillation tower 9;

[0081] Among them, the preheating temperature is 65° C., the pressure is 0.15 MPa, the number of plates of the methanol distillation tower 9 is 17, the reflux ratio is 1.94, the distillate feed ratio is 0.80, and the pressure is 0.1 MPa.

[0082] S4, the circulation part, the unreacted circulating gas stream in S2 is circulated back to the pretreatment part, mixed with the raw gas stream and then recycled;

[0083] The bottom stream of the reaction distillation tower 5 in S2 enters the pervaporation solvent recovery device 10, and a high-purity solvent stream is separated by the pervaporation solvent recovery device 10. The high-purity solvent stream is recycled back to the pretreatment part and mixed with the solvent stream for recycling.

[0084] The raw gas circulation feed ratio is 0.06; the solvent circulation feed ratio is 1319.

[0085] The process material data are shown in Table 3:

[0086] Table 3

[0087]

[0088]

[0089] The results show that the methanol output of this process is 100.05kt / y with a purity of 99.90%, a single-pass conversion rate of carbon dioxide of 97.62%, and a carbon dioxide utilization rate of 97.60%.

[0090] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0091] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation, characterized in that: The following steps are involved: S1, pretreatment part, hydrogen and carbon dioxide are mixed into a raw gas stream, which passes through a multi-stage compressor (1) and then passes through a first heat exchanger (2) to obtain a pretreated raw gas stream; the solvent stream passes through a booster pump (3) and then passes through a second heat exchanger (4) to obtain a pretreated solvent stream; S2, methanol synthesis part, the pre-treated raw material gas stream enters from the bottom of the reaction distillation tower (5), the pre-treated solvent stream enters from the top of the reaction distillation tower (5), and reacts to generate methanol and water. The unreacted gas, part of the methanol and part of the water in the reaction distillation tower (5) flow out from the top of the reaction distillation tower (5) and are separated into two parts by a gas-liquid separator (11), one part is the unreacted circulating gas stream, and the other part is the mixed stream of methanol and water. The remaining part in the reaction distillation tower (5) flows out from the bottom of the reaction distillation tower (5) to obtain a bottom stream; S3, methanol refining part, the mixed stream enters the methanol refining system, is first decompressed by the pressure reducing valve (6), and then preheated by the heat exchanger (7), and then enters the flash tank (8). After the non-condensable steam is relaxed, the rest of the flash tank (8) enters the methanol distillation tower (9), and the refined methanol product is obtained by the methanol distillation tower (9); S4, the circulation part, the unreacted circulating gas stream in S2 is circulated back to the pretreatment part, mixed with the raw material gas stream and then recycled; the bottom stream of the reaction distillation tower (5) in S2 enters the pervaporation solvent recovery device (10), and the high-purity solvent stream is separated by the pervaporation solvent recovery device (10), and the high-purity solvent stream is circulated back to the pretreatment part and mixed with the solvent stream for recycling.

2. A liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation according to claim 1, characterized in that: The molar ratio of hydrogen to carbon dioxide in the raw gas stream in S1 is 2 to 3.5, the pressure is 4.5 to 10.0 MPa, and the temperature is 220°C to 300°C.

3. The liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation according to claim 1, characterized in that: The solvent in the solvent stream is a polar solvent, a non-polar solvent or a mineral oil solvent.

4. The liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation according to claim 3, characterized in that: The polar solvents are tetraethylene glycol dimethyl ether, dimethylformamide and dimethylacetamide, the non-polar solvents are squalane, n-octane, decalin, tetralin and n-dodecane, and the mineral oil solvents are Freezene-100, Witco-40, Drakeol-7 and Multitherm-PGI.

5. The liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation according to claim 1, characterized in that: The molar ratio of the solvent in the solvent stream in S1 to the molar ratio of the raw gas is 0.6 to 1, the pressure is 4.5 to 10.0 MPa, and the temperature is 220°C to 300°C.

6. The liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation according to claim 1, characterized in that: The methanol synthesis catalyst in the reaction distillation tower (5) in S2 is a copper-based catalyst, the synthesis pressure in the reaction distillation tower (5) is 4.5-10.0 MPa, the temperature is 220° C.-300° C., and the reflux ratio of the reaction distillation tower (5) is 1.0-1.

8.

7. The liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation according to claim 1, characterized in that: The pressure of the methanol distillation tower (9) in S3 is 0.1-0.5 MPa, the temperature is 30°C-60°C, and the reflux ratio of the methanol distillation tower (9) is 0.2-0.

3.

8. The liquid phase methanol synthesis system based on reactive distillation coupled with pervaporation according to claim 1, characterized in that: The circulating feed ratio of the unreacted circulating gas stream in S4 is 0.02 to 0.08.

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