In-situ separation reactor, methanol preparation system and methanol preparation method

Abstract

The invention discloses an in-situ separation reactor, a methanol preparation system and a methanol preparation method, and relates to the technical field of organic compound production and preparation. The in-situ separation reactor comprises a reaction part which comprises a gas inlet and a reaction cavity, and the reaction cavity is filled with a catalyst; the condensation separation part comprises a separation cavity, a liquid outlet, a gas outlet and a condensation pipe; the condensation pipe is arranged in the separation cavity, and the liquid outlet and the gas outlet are connected with the separation cavity; the heat insulation and ventilation part comprises a gas circulation hole channel, and the reaction part is communicated with the separation cavity through the gas circulation hole channel; wherein the heat insulation and ventilation part is arranged between the reaction part and the condensation separation part. The invention can improve the conversion rate of the feed gas and reduce the energy consumption at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of production and preparation of organic compounds, and in particular to an in-situ separation reactor, a methanol preparation system and a methanol preparation method. Background Art

[0002] The exploitation and application of fossil energy has greatly promoted the prosperity of social economy. However, the ensuing environmental pollution problems, especially the global warming caused by the burning of fossil fuels, are forcing us to take urgent measures to alleviate this crisis. Energy storage technology is a key link in the effective utilization of renewable energy such as wind and solar energy. Methanol, as a fuel that remains liquid at room temperature, has the advantages of convenient storage, low transportation cost and high compatibility with the existing industrial system. It is regarded as an ideal chemical energy storage medium. By using renewable electricity to electrolyze water to produce hydrogen, and combining hydrogen with carbon dioxide to synthesize green methanol, it is expected to not only achieve large-scale and stable utilization of unstable renewable energy such as wind and solar energy, but also convert captured carbon dioxide into high-value-added chemicals, thereby promoting carbon dioxide emission reduction.

[0003] However, the current process of synthesizing methanol from carbon dioxide hydrogenation faces the problem of high energy consumption, which limits the competitiveness of green methanol in the market. Due to the low equilibrium conversion rate of carbon dioxide, traditional green methanol production requires a high recycling ratio to ensure full utilization of raw materials. In this process, the operation of the recycling compressor consumes a large amount of high-grade energy, and the recycling structure greatly increases the response time of the synthesis system. At present, there is a lack of technology that can solve these problems and achieve low-energy and flexible methanol production. Summary of the invention

[0004] The main purpose of the present invention is to provide an in-situ separation reactor, a methanol preparation system and a methanol preparation method, aiming to improve the conversion rate of raw gas while reducing energy consumption.

[0005] To achieve the above objectives, in a first aspect, the present invention provides an in-situ separation reactor, comprising:

[0006] The reaction part comprises an air inlet and a reaction chamber, wherein the reaction chamber is filled with a catalyst;

[0007] The condensation separation part comprises a separation cavity, a liquid outlet, a gas outlet and a condenser; the condenser is arranged in the separation cavity, and the liquid outlet and the gas outlet are connected to the separation cavity;

[0008] A heat-insulating and breathable part, comprising a gas flow channel, wherein the gas flow channel connects the reaction part and the separation cavity;

[0009] Wherein, the heat-insulating and breathable part is arranged between the reaction part and the condensation and separation part.

[0010] In some embodiments, the separation cavity and the condenser are cylindrical, the condenser is arranged along the axial direction of the separation cavity, the diameter of the condenser is smaller than the diameter of the separation cavity, and the condenser is filled with a condensing medium; the heat-insulating and breathable part is sleeved on the outer wall of the separation cavity, and the reaction part is sleeved on the outer wall of the heat-insulating and breathable part.

[0011] In some embodiments, a heating device is provided in the reaction section.

[0012] In some embodiments, the condensation separation part further includes a spiral guide structure arranged around the outer wall of the condensation tube.

[0013] In some embodiments, the material of the heat-insulating and breathable portion includes at least one of wire mesh, rock wool, and glass wool.

[0014] In a second aspect, the present invention provides a methanol preparation system, comprising:

[0015] An isothermal reaction module, comprising an isothermal reactor, wherein the isothermal reactor is used for performing a methanol synthesis reaction;

[0016] An in-situ separation reaction module, comprising at least one repeated reaction unit, wherein the at least one repeated reaction unit comprises the in-situ separation reactor of the first aspect of the present invention and an isothermal reactor connected in series with the in-situ separation reactor;

[0017] Wherein, the isothermal reactor in the isothermal reaction module and the in-situ separation reactor in the in-situ separation reaction module are connected in series.

[0018] In some embodiments, the isothermal reactor in the isothermal reaction module and the isothermal reactor in the in-situ separation reaction module both include a catalytic bed, and a heat exchange tube is disposed on the catalytic bed.

[0019] In some embodiments, the methanol preparation system further includes a cooling medium circulation module and a heating medium circulation module.

[0020] Wherein, the cooling medium circulation module includes a cooling medium connecting pipe and a heat absorbing device;

[0021] The refrigerant connecting pipe is used to connect the condensing pipes of each in-situ separation reactor in series; the heat absorbing device is connected to the outlet of the condensing pipe of the last stage in-situ separation reactor; the heat absorbing device includes a desorption tower in the carbon capture system;

[0022] The heating medium circulation module includes a heating medium connecting pipe,

[0023] The heating medium connecting pipe is used to connect in series the heating devices of each in-situ separation reactor and the heat exchange pipes of the isothermal reactor in the in-situ separation reaction module.

[0024] In a third aspect, the present invention provides a method for preparing methanol, comprising the following steps:

[0025] Carbon dioxide, carbon monoxide and hydrogen are mixed to obtain a mixed gas, and the mixed gas is introduced into the methanol preparation system of the second aspect of the present invention to prepare methanol.

[0026] In some embodiments, the molar ratio of carbon dioxide, carbon monoxide and hydrogen in the mixed gas is 1:1:5, the temperature of the mixed gas is 170° C. to 220° C., and the pressure of the mixed gas is 30 bar to 80 bar; and / or,

[0027] The heat exchange medium in the heat exchange tube of the isothermal reactor in the isothermal reaction module is medium-pressure water, and the temperature of the heat exchange medium entering the heat exchange tube of the isothermal reactor in the isothermal reaction module is 180° C. to 250° C.; and / or,

[0028] The temperature of the cooling medium in the condenser pipe passing into the in-situ separation reactor is 40°C to 100°C.

[0029] The in-situ separation reactor provided by the present invention can separate the reaction products while reacting, significantly increasing the conversion rate of the raw gas. The methanol preparation system provided by the present invention connects the isothermal reactor in the isothermal reaction module and the in-situ separation reactor in the in-situ separation reaction module in series. First, the traditional isothermal reactor can be used to complete the partial conversion of the raw material. After the reaction, the gas enters the in-situ separation reaction module composed of several minimum reaction units to achieve the improvement of the conversion rate. The in-situ separation reactor in the in-situ separation reaction module separates the reaction products while reacting, and the conversion rate of the raw gas will be significantly increased, and can even be close to 100% under the preferred working conditions. This follows the Le Chatelier principle. Under the condition of continuous separation of the reaction products, the reaction can proceed in the forward direction, thereby improving the conversion rate. The methanol preparation system of the present invention has the advantage of high raw gas conversion rate, which obviously has significant technical effects compared with the existing methanol synthesis technology, and can greatly simplify the reaction system, improve reliability and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0031] Figure 1 A schematic structural diagram of an in-situ separation reactor according to an embodiment of the present invention.

[0032] Figure 2 A schematic structural diagram of an embodiment of a methanol preparation system provided by an embodiment of the present invention;

[0033] Figure 3 A schematic structural diagram of another embodiment of a methanol preparation system provided in an embodiment of the present invention.

[0034] Description of Figure Numbers:

[0035] 1-first compressor; 2-first cooler; 3-second compressor; 4-second cooler; 5-third compressor; 6-third cooler; 7-fourth compressor; 8-mixer; 9-heater; 10-isothermal reactor in isothermal reaction module; 11-first in-situ separation reactor; 12-first isothermal reactor; 13-second in-situ separation reactor; 14-second isothermal reactor; 15-third in-situ separation reactor; 16-third isothermal reactor; 17-liquid storage tank; 18-gas storage tank; 19-desorption tower in carbon capture system;

[0036] 111-reaction part; 112-condensation separation part; 112a-separation cavity; 112b-condensation tube; 112c-spiral flow guide structure; 113-heat-insulating and breathable part.

[0037] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0038] 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.

[0039] It should be noted that if a directional indication is involved in the embodiment of the present invention, the directional indication is only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0040] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0041] The exploitation and application of fossil energy has greatly promoted the prosperity of social economy. However, the ensuing environmental pollution problems, especially the global warming caused by the burning of fossil fuels, are forcing us to take urgent measures to alleviate this crisis. Energy storage technology is a key link in the effective utilization of renewable energy such as wind and solar energy. Methanol, as a fuel that remains liquid at room temperature, has the advantages of convenient storage, low transportation cost and high compatibility with the existing industrial system. It is regarded as an ideal chemical energy storage medium. By using renewable electricity to electrolyze water to produce hydrogen, and combining hydrogen with carbon dioxide to synthesize green methanol, it is expected to not only achieve large-scale and stable utilization of unstable renewable energy such as wind and solar energy, but also convert captured carbon dioxide into high-value-added chemicals, thereby promoting carbon dioxide emission reduction.

[0042] However, the current process of synthesizing methanol from carbon dioxide hydrogenation faces the problem of high energy consumption, which limits the competitiveness of green methanol in the market. Due to the low equilibrium conversion rate of carbon dioxide, traditional green methanol production requires a high recycling ratio to ensure full utilization of raw materials. In this process, the operation of the recycling compressor consumes a large amount of high-grade energy, and the recycling structure greatly increases the response time of the synthesis system. At present, there is a lack of technology that can solve these problems and achieve low-energy and flexible methanol production.

[0043] In view of this, in a first aspect, an embodiment of the present invention provides an in-situ separation reactor, comprising:

[0044] The reaction part 111 includes an air inlet and a reaction chamber, wherein the reaction chamber is filled with a catalyst;

[0045] The condensation separation part 112 comprises a separation cavity 112a, a liquid outlet, a gas outlet and a condensation pipe 112b; the condensation pipe 112b is arranged in the separation cavity 112a, and the liquid outlet and the gas outlet are connected to the separation cavity 112a;

[0046] The heat-insulating and breathable portion 113 includes a gas flow channel, and the gas flow channel connects the reaction portion 111 and the separation cavity 112a;

[0047] The heat-insulating and breathable portion 113 is disposed between the reaction portion 111 and the condensation and separation portion 112 .

[0048] In traditional preparation processes, the products are separated and purified after the reaction is completed. In contrast, the in-situ separation reactor separates the products during the reaction, thereby improving the reaction kinetics and maintaining a high yield.

[0049] It should be noted that, in the embodiment of the present invention, the catalyst filled in the reaction chamber is a copper-based catalyst, and the in-situ separation reactor can achieve in-situ separation of water, thereby avoiding the problem of copper-based catalysts used in methanol production being easily deactivated when exposed to water.

[0050] In some embodiments, the separation cavity 112a and the condenser 112b are cylindrical, the condenser 112b is arranged along the axial direction of the separation cavity 112a, the diameter of the condenser 112b is smaller than the diameter of the separation cavity 112a, and the condenser 112b is filled with a condensing medium; the heat-insulating and breathable portion 113 is sleeved on the outer wall of the separation cavity 112a, and the reaction portion 111 is sleeved on the outer wall of the heat-insulating and breathable portion 113.

[0051] The condensing pipe 112b has a relatively simple structure, and the cooling medium can be reused. The heat absorbed by the cooling medium in the condensation separation part 112 can be further utilized, thus saving energy consumption.

[0052] In some embodiments, a heating device is provided in the reaction part 111. The reaction part 111 is heated by the heating device to stabilize the temperature of the reaction system.

[0053] In some embodiments, the condensation separation unit 112 further includes a spiral guide structure 112c disposed around the outer wall of the condensation tube 112b. The cooling medium in the condensation tube 112b is used to condense, separate and collect the reaction product gas on the spiral guide structure 112c.

[0054] In some embodiments, the material of the heat-insulating and breathable part 113 includes at least one of wire mesh, rock wool, and glass wool. The heat-insulating and breathable part 113 is disposed between the reaction part 111 and the condensation separation part 112 to allow the reaction product gas to pass through and reduce the heat loss of the reaction part 111.

[0055] In a second aspect, the present invention provides a methanol preparation system, comprising:

[0056] An isothermal reaction module, comprising an isothermal reactor, wherein the isothermal reactor is used for performing a methanol synthesis reaction;

[0057] An in-situ separation reaction module, comprising at least one repeated reaction unit, wherein the at least one repeated reaction unit comprises the in-situ separation reactor of the first aspect of the present invention and an isothermal reactor connected in series with the in-situ separation reactor;

[0058] Wherein, the isothermal reactor in the isothermal reaction module and the in-situ separation reactor in the in-situ separation reaction module are connected in series.

[0059] The traditional recirculation methanol synthesis structure is replaced by a series structure, thus avoiding the use of a recirculation compressor, thereby reducing operating costs and investment costs. In addition, the series structure significantly improves the response characteristics of the system, is more adaptable to the dynamic characteristics of the new energy supply side, and improves the efficiency of methanol synthesis.

[0060] The methanol preparation system adopts at least one repeated reaction unit, which can realize modular assembly of the reaction system and can flexibly adjust the number of at least one repeated reaction unit according to the energy supply volume, for example, 2-10 repeated reaction units.

[0061] In some embodiments, the isothermal reactor in the isothermal reaction module and the isothermal reactor in the in-situ separation reaction module both include a catalytic bed, on which a heat exchange tube is disposed. The reaction heat is removed by the medium flowing in the heat exchange tube, thereby cooling the isothermal reactor and completing the preliminary conversion of the raw materials to generate methanol and water.

[0062] The reverse water gas reaction and methanol synthesis reaction mainly occur in the isothermal reaction module and the in-situ separation reaction module, respectively.

[0063] In some embodiments, the isothermal reaction module may further include: a plurality of compressors, a plurality of coolers, a mixer, and a heater. Among them, a plurality of compressors are arranged in series in sequence and configured to pressurize carbon-containing gas, i.e., carbon dioxide or a mixture of carbon dioxide and carbon monoxide. Each cooler is arranged between adjacent compressors and configured to cool the carbon dioxide compressed by the upstream compressor. The compressor and the cooler together form a multi-stage compression intermediate cooling structure. The pressure of the raw gas can be increased step by step by using a plurality of compressors, and the raw gas can be pressurized to the pressure range required by the isothermal reactor in the isothermal reaction module. The compressed raw gas may be overheated, which is not conducive to further compression by the downstream compressor, so the compressed superheated gas is cooled by a cooler.

[0064] Hydrogen can be produced by renewable energy using green technology, such as electrolysis using renewable energy, and the pressure of hydrogen is equivalent to the pressure of compressed carbon-containing gas. In some embodiments, the pressure of hydrogen itself or after compression can be equivalent to the pressure of compressed carbon dioxide.

[0065] The mixer is configured to mix hydrogen and carbon-containing gas compressed by multiple compressors to obtain a mixed gas of carbon-containing gas and hydrogen as a raw material gas for an isothermal separation reactor in the isothermal reaction module.

[0066] The heater is disposed between the mixer and the isothermal reactor, and is configured to preheat the raw gas mixed by the mixer and supply it to the isothermal reactor. In some embodiments, the temperature range is configured to be 170°C to 220°C.

[0067] The isothermal reactor can be configured as a water-cooled reactor, the cooling medium can be water, and the inlet temperature range of the cooling medium is set to 180° C. to 250° C. The cooling medium in this temperature range can create a higher reaction rate, thereby achieving a higher product conversion rate, and can also generate a heat source with a high enough temperature to supply other heat-using equipment. In some embodiments, the inlet temperature of the cooling medium can be set higher.

[0068] In an embodiment of the present invention, according to the ratio of raw materials and operating conditions, the one-way conversion rate of hydrogen in the isothermal reaction module can reach 10% to 40%. In some embodiments, the molar ratio of carbon dioxide, carbon monoxide and hydrogen in the mixed gas at the inlet of the raw gas is 1:1:5, the temperature range is configured to be 170°C to 220°C, the pressure range is configured to be 30bar to 80bar, and the isothermal reactor is filled with a copper-based catalyst. That is, the raw gas enters the isothermal reactor after being pressurized and heated to the reaction conditions by auxiliary equipment, and the temperature is any value between 170°C and 220°C; the pressure is any value between 30bar and 80bar. Preferably, the pressure can be set to 70bar, and the increase in pressure can increase the degree of methanol synthesis reaction.

[0069] In some embodiments, the methanol preparation system may further include a gas storage tank and a liquid storage tank.

[0070] The liquid storage tank is connected to the in-situ separation reactor and is configured to receive the methanol and water separated by the in-situ separation reactor.

[0071] The in-situ separation reactor can achieve a separation rate of methanol and water of more than 90%, and particularly preferably more than 99%, thereby achieving a higher feedstock conversion rate and a higher methanol selectivity.

[0072] The cooling medium in the condenser of the in-situ separation reactor can be water, and the inlet temperature of the cooling medium of the in-situ separation reactor is 40° C. to 100° C. The above cooling medium temperature can create a higher separation ratio and condensation separation rate, thereby achieving a higher product conversion rate. In some embodiments, the inlet temperature of the cooling medium of the in-situ separation reactor can be set to be lower.

[0073] A specific reaction process of the methanol preparation system of the above embodiment may include:

[0074] The carbon dioxide raw gas is compressed in multiple stages and then cooled and pressurized to 70 bar (70 bar is the preferred value, and the pressure for specific applications can be selected within the range of 30 bar to 80 bar). The mixer adiabatically mixes the compressed carbon dioxide or the carbon dioxide and carbon monoxide mixed gas with hydrogen from the water electrolysis system. The pressure of the hydrogen is consistent with the compression pressure of the carbon dioxide, for example, both are 70 bar. The molar ratio of carbon dioxide, carbon monoxide and hydrogen in the mixed gas is 1:1:5, and the mixed gas is heated in a heater to a reaction temperature of 180°C (180°C is the preferred value, and the temperature for specific applications can be selected within the range of 170°C to 220°C).

[0075] The raw gas at 70 bar and 180°C enters the isothermal reactor in the isothermal reaction module for reverse water gas reaction and methanol synthesis reaction. The isothermal reactor is configured as a water-cooled reactor, and a heat exchange tube is arranged in the catalyst bed. The medium flowing in the tube exchanges heat with the reaction bed to achieve cooling of the reactor.

[0076] The cooling medium in the isothermal reactor in the isothermal reaction module is medium-pressure water, the inlet temperature is 230°C (230°C is the preferred value, and the temperature of the specific application can be selected within the range of 180°C to 250°C), and the flow direction is the same as the flow direction of the reaction gas. When the cooling medium is medium-pressure water with an inlet temperature of 230°C, the temperature of the reaction bed can be effectively controlled and a faster reaction rate can be guaranteed, thereby achieving effective preliminary conversion of the raw materials and reducing the volume of the reactor. In addition, the gas after the preliminary conversion contains methanol and water with a sufficiently high concentration, thereby providing sufficient mass transfer power for the in-situ separation of the product in the downstream in-situ separation reaction module. On the other hand, the use of a higher cooling medium is more conducive to system-level heat integration.

[0077] The gas discharged from the isothermal reaction module enters the in-situ separation reaction module to achieve further conversion of the raw gas. The in-situ separation reaction module is mainly composed of multiple repeated reaction units in series, and the smallest reaction unit is composed of an in-situ separation reactor and an isothermal reactor.

[0078] The reaction gas (reaction products and unreacted reactants) in the reaction part of the in-situ separation reactor can diffuse to the condensation separation part through the porous heat-insulating and breathable part. In the condensation separation part, it contacts with the cooling medium, and the condensation separation of the reaction gas and the diversion of the liquid can be achieved through the spiral guide structure. The cooling medium can condense the gaseous water, that is, the product water can be separated from the reaction system, thereby achieving the purpose of reacting and separating at the same time and improving the reaction conversion rate.

[0079] The cooling medium in the in-situ separation reactor condenses gaseous methanol and water, thus separating the product methanol and water from the reaction system. The cooling medium in the in-situ separation reactor is atmospheric pressure water, with an inlet temperature of 90°C and a flow direction that is the same as that of the reaction gas. Setting the cooling medium to atmospheric pressure water with an inlet temperature of 90°C can improve the separation efficiency of the product.

[0080] In order to maintain the relative stability of the reaction temperature, an additional heating device is arranged in the reaction section to heat the reaction gas. The heating device can use a heating pipe, and medium-pressure water is passed through the pipe as a heating medium, or it can be an electric heater. The energy quality of medium-pressure water as a heating medium is lower than that of electricity, and using water as a heating medium is more conducive to system-level heat integration. The inlet temperature of the heating medium is 230°C. The heating medium at this temperature can effectively increase the reaction rate, stabilize the temperature of the reaction system, and reduce the energy quality loss caused by heat transfer.

[0081] There are two streams of material at the outlet of the in-situ separation reactor. One is the liquid component separated by condensation, mainly methanol and water, which flows out along the flow channel of the separation part and is collected by the liquid storage tank. The other is the gas component, which will enter the isothermal reactor for further reaction.

[0082] The outlet gas of the last-stage minimum reaction unit is a small amount of unreacted raw gas and high-temperature product gas, which can be collected by a gas storage tank and further processed.

[0083] In some embodiments, the methanol preparation system also includes a cooling medium circulation module and a heating medium circulation module, wherein the cooling medium circulation module includes a refrigerant connecting pipe and a heat absorption device; the refrigerant connecting pipe is used to connect the condenser pipes of each in-situ separation reactor in series; the heat absorption device is connected to the condenser pipe outlet of the last-stage in-situ separation reactor; the heat absorption device includes a desorption tower in a carbon capture system; the heating medium circulation module includes a heating medium connecting pipe, and the heating medium connecting pipe is used to connect the heating devices of each in-situ separation reactor in the in-situ separation reaction module and the heat exchange pipes of the isothermal reactor in series.

[0084] The inlet of the heat absorbing device is connected to the outlet of the cooling medium of the in-situ separation reactor in the last minimum reaction unit, and the outlet of the heat absorbing device is connected to the inlet of the cooling medium of the in-situ separation reactor in the first minimum reaction unit, and is configured to absorb the cooling medium heated by all the in-situ separation reactors, so as to recycle the cooling medium. The heat absorbing device can be a desorption tower in the carbon capture system, and the desorption tower uses the heat of the cooling medium to desorb the absorbent of the carbon capture system, thereby realizing the cascade utilization of energy and improving the overall energy utilization efficiency of the system. The carbon capture system can also capture carbon dioxide, and the obtained carbon dioxide is further used as the raw gas for the methanol synthesis reaction, thereby achieving the purpose of emission reduction.

[0085] In a third aspect, the present invention provides a method for preparing methanol, comprising the following steps: mixing carbon dioxide, carbon monoxide and hydrogen to obtain a mixed gas, and passing the mixed gas into the methanol preparation system of the second aspect of the present invention to prepare methanol.

[0086] In some embodiments, the molar ratio of carbon dioxide, carbon monoxide and hydrogen in the mixed gas is 1:1:5, the temperature of the mixed gas is 170° C. to 220° C., and the pressure of the mixed gas is 30 bar to 80 bar; and / or,

[0087] The heat exchange medium in the heat exchange tube of the isothermal reactor in the isothermal reaction module is medium-pressure water, and the temperature of the heat exchange medium entering the heat exchange tube of the isothermal reactor in the isothermal reaction module is 180° C. to 250° C.; and / or,

[0088] The temperature of the cooling medium in the condenser pipe passing into the in-situ separation reactor is 40°C to 100°C.

[0089] For example, see Figure 2 , which shows an embodiment of a methanol preparation system, wherein carbon dioxide is sequentially passed through a first compressor 1, a first cooler 2, a second compressor 3, a second cooler 4, and a third compressor 5 to obtain pressurized carbon dioxide, and hydrogen is sequentially passed through a third cooler 6 and a fourth compressor 7 to obtain pressurized hydrogen, and the pressurized carbon dioxide and pressurized hydrogen are mixed in a mixer 8, and enter an isothermal reactor 10 in an isothermal reaction module after passing through a heater 9, and the reaction gas product and the unreacted raw gas enter an in-situ separation reaction module, and sequentially enter a first in-situ separation reactor 11, a first isothermal reactor 12, a second in-situ separation reactor 13, a second isothermal reactor 14, a third in-situ separation reactor 15, and a third isothermal reactor 16. Methanol and water are condensed and separated in the first in-situ separation reactor 11, the second in-situ separation reactor 13, and the third in-situ separation reactor 15, and are collected and entered into a liquid storage tank 17, and the gas exiting the outlet of the third isothermal reactor 16 is a small amount of unreacted raw gas and high-temperature product gas, which is collected by a gas storage tank 18 and further processed.

[0090] See also Figure 3, which shows another embodiment of the methanol preparation system, carbon dioxide is sequentially passed through the first compressor 1, the first cooler 2, the second compressor 3, the second cooler 4, and the third compressor 5 to obtain pressurized carbon dioxide, hydrogen is sequentially passed through the third cooler 6 and the fourth compressor 7 to obtain pressurized hydrogen, the pressurized carbon dioxide and the pressurized hydrogen are mixed in the mixer 8, and enter the isothermal reactor 10 in the isothermal reaction module after passing through the heater 9, the reaction gas product and the unreacted raw gas enter the in-situ separation reaction module, and sequentially enter the first in-situ separation reactor 11, the first isothermal reactor 12, the second in-situ separation reactor 13, the second isothermal reactor 14, the third in-situ separation reactor 15, and the third isothermal reactor 16. Methanol and water are condensed and separated in the first in-situ separation reactor 11, the second in-situ separation reactor 13, and the third in-situ separation reactor 15, and are collected and entered into the liquid storage tank 17. The gas exiting the third isothermal reactor 16 is a small amount of unreacted raw gas and high-temperature product gas, which is collected by the gas storage tank 18 and further processed.

[0091] Among them, the cooling medium outlet of the desorption tower 19 in the carbon capture system is connected to the condenser pipes in the first in-situ separation reactor 11, the second in-situ separation reactor 13 and the third in-situ separation reactor 15 in sequence, and the cooling medium outlet of the third in-situ separation reactor 15 is connected to the cooling medium inlet of the desorption tower 19 to form a cooling medium circulation loop.

[0092] The heating medium flowing out from the heat exchange tube of the isothermal reactor 10 in the isothermal reaction module (the heating medium is the medium-pressure water for cooling the isothermal reactor 10 in the isothermal reaction module) sequentially enters the heating pipe of the reaction part in the first in-situ separation reactor 11, the heat exchange tube of the first isothermal reactor 12, the heating pipe of the reaction part in the second in-situ separation reactor 13, the heat exchange tube of the second isothermal reactor 14, the heating pipe of the reaction part in the third in-situ separation reactor 15, the heat exchange tube of the third isothermal reactor 16, and then enters the heat exchange tube of the isothermal reactor 10 in the isothermal reaction module to form a heating medium circulation loop.

[0093] In summary, the in-situ separation reactor provided by the present invention can separate the reaction products while reacting, significantly increasing the conversion rate of the raw gas. The methanol preparation system provided by the present invention connects the isothermal reactor in the isothermal reaction module in series with the in-situ separation reactor in the in-situ separation reaction module. First, the traditional isothermal reactor can be used to complete the partial conversion of the raw material. After the reaction, the gas enters the in-situ separation reaction module composed of several minimum reaction units to achieve the improvement of the conversion rate. The in-situ separation reactor in the in-situ separation reaction module separates the reaction products while reacting, and the conversion rate of the raw gas will be significantly increased, and can even be close to 100% under the preferred working conditions. This follows the Le Chatelier principle. Under the condition of continuous separation of the reaction products, the reaction can proceed in the forward direction, thereby improving the conversion rate. The methanol preparation system of the present invention has the advantage of high conversion rate of raw gas, which obviously has significant technical effects compared with the existing methanol synthesis technology, and can greatly simplify the reaction system, improve reliability and economy.

[0094] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An in-situ separation reactor, characterized in that: include: The reaction part comprises an air inlet and a reaction chamber, wherein the reaction chamber is filled with a catalyst; A condensation separation part, comprising a separation cavity, a liquid outlet, a gas outlet and a condensation pipe; The condenser is arranged in the separation cavity, and the liquid outlet and the gas outlet are connected to the separation cavity; A heat-insulating and breathable part, comprising a gas flow channel, wherein the gas flow channel connects the reaction part and the separation cavity; Wherein, the heat-insulating and breathable part is arranged between the reaction part and the condensation and separation part.

2. The in-situ separation reactor according to claim 1, characterized in that: The separation cavity and the condenser are cylindrical, the condenser is arranged along the axial direction of the separation cavity, the diameter of the condenser is smaller than the diameter of the separation cavity, and the condenser is filled with condensing medium; the heat-insulating and breathable part is sleeved on the outer wall of the separation cavity, and the reaction part is sleeved on the outer wall of the heat-insulating and breathable part.

3. The in-situ separation reactor according to claim 1, characterized in that: A heating device is provided in the reaction section.

4. The in-situ separation reactor according to claim 1, characterized in that: The condensation separation part also includes a spiral guide structure arranged around the outer wall of the condensation tube.

5. The in-situ separation reactor according to claim 1, characterized in that: The material of the heat-insulating and breathable part includes at least one of wire mesh, rock wool and glass wool.

6. A methanol preparation system, characterized in that: include: An isothermal reaction module, comprising an isothermal reactor, wherein the isothermal reactor is used for performing a methanol synthesis reaction; An in-situ separation reaction module, comprising at least one repeated reaction unit, wherein the at least one repeated reaction unit comprises the in-situ separation reactor according to any one of claims 1 to 4 and an isothermal reactor connected in series with the in-situ separation reactor; Wherein, the isothermal reactor in the isothermal reaction module and the in-situ separation reactor in the in-situ separation reaction module are connected in series.

7. The methanol production system according to claim 5, characterized in that: The isothermal reactor in the isothermal reaction module and the isothermal reactor in the in-situ separation reaction module both include a catalytic bed layer, and a heat exchange tube is arranged on the catalytic bed layer.

8. The methanol preparation system according to claim 7, characterized in that: The methanol preparation system also includes a cooling medium circulation module and a heating medium circulation module. Wherein, the cooling medium circulation module includes a cooling medium connecting pipe and a heat absorbing device; The refrigerant connecting pipe is used to connect the condensing pipes of each in-situ separation reactor in series; the heat absorbing device is connected to the outlet of the condensing pipe of the last stage in-situ separation reactor; the heat absorbing device includes a desorption tower in the carbon capture system; The heating medium circulation module includes a heating medium connecting pipe, The heating medium connecting pipe is used to connect in series the heating devices of each in-situ separation reactor and the heat exchange pipes of the isothermal reactor in the in-situ separation reaction module.

9. A method for preparing methanol, characterized in that: The following steps are involved: Carbon dioxide, carbon monoxide and hydrogen are mixed to obtain a mixed gas, and the mixed gas is introduced into the methanol preparation system as described in any one of claims 6 to 8 to prepare methanol.

10. The method for preparing methanol according to claim 9, characterized in that: The molar ratio of carbon dioxide, carbon monoxide and hydrogen in the mixed gas is 1:1:5, the temperature of the mixed gas is 170° C. to 220° C., and the pressure of the mixed gas is 30 bar to 80 bar; and / or, The heat exchange medium in the heat exchange tube of the isothermal reactor in the isothermal reaction module is medium-pressure water, and the temperature of the heat exchange medium entering the heat exchange tube of the isothermal reactor in the isothermal reaction module is 180° C. to 250° C.; and / or, The temperature of the cooling medium in the condenser pipe passing into the in-situ separation reactor is 40°C to 100°C.

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