A method and system for the production of green methanol by electrolytic coupling of methane synthesis

Abstract

The application relates to the technical field of methanol regeneration, in particular to a method and system for preparing green methanol through electrolysis coupling methane synthesis, which comprises the following steps: first heat exchange is performed on air to obtain heat-exchanged air; second heat exchange is performed on water to obtain heat-exchanged water; first heating is performed on a solvent raw material and the heat-exchanged water to obtain water vapor raw material; second heating is performed on the heat-exchanged air to obtain air raw material; electrolysis is performed on the air raw material and the water vapor raw material to obtain hydrogen; third heat exchange is performed on the hydrogen to obtain heat-exchanged hydrogen; wherein the heat exchange medium of the third heat exchange comprises the heat-exchanged water and / or the solvent raw material; carbon dioxide raw material and the heat-exchanged hydrogen are subjected to methanol synthesis to obtain crude methanol product; fourth heat exchange and impurity removal treatment are performed on the crude methanol product to obtain methanol product; wherein the heat exchange medium of the fourth heat exchange comprises the solvent raw material. Through the method, the heat of the raw materials and the product is effectively recovered, so that the energy utilization rate of the coupling process is improved.

Description

Technical Field

[0001] This application relates to the field of regenerated methanol technology, and in particular to a method and system for preparing green methanol by electrolytic coupling of methane synthesis. Background Technology

[0002] Currently, the main raw materials for methanol production come from coal, natural gas, and coke oven gas. Coal-based methanol production is the primary method, but this process emits large amounts of carbon dioxide, typically about 3 tons per ton of methanol produced. Additionally, the production process generates significant amounts of sulfur and nitrogen oxides, necessitating tail gas treatment. Solid oxide electrolyzers (SOECs) are reverse reaction devices for fuel cells, offering advantages such as fast reaction rates, environmental friendliness, and extremely high reaction rates and energy conversion efficiency. SOECs typically use perovskite as the anode, cerium oxide or mixed conductor oxides as the cathode, and zirconium oxide-based or cerium oxide-based electrolytes. By applying an additional current, water vapor can be electrolyzed into hydrogen and oxygen at high temperatures of 600℃–1000℃. The power source for the electrolysis process can be green energy generated by photovoltaic or wind power. Furthermore, after pretreatment such as drying and granulation, biomass can be gasified in a biomass gasifier to produce feed gas including CO, H2, CO2, and CH4. This feed gas undergoes desulfurization and decarbonization, H2 and CO volume ratio adjustment, and CH4 reforming to become carbon dioxide feedstock suitable for methanol synthesis. Therefore, by coupling hydrogen produced by SOEC and carbon dioxide feedstock from biomass, relatively pure methanol can be synthesized without emitting harmful gases such as sulfur or nitrogen oxides.

[0003] However, in the coupling process, the electrolysis of solid oxide batteries and the synthesis of methanol require a large amount of steam and generate a large amount of reaction heat. The process of exchanging high-grade steam for low-grade steam and using circulating water to remove the reaction heat will result in a large amount of energy waste. Summary of the Invention

[0004] This application provides a method and system for the electrolytic coupling of methane to synthesize green methanol, in order to solve the following technical problem: how to improve the energy utilization rate of the coupling process.

[0005] In a first aspect, this application provides a method for the electrolytic coupling of methane to prepare green methanol, the method comprising:

[0006] The air undergoes a first heat exchange to obtain heat-exchanged air;

[0007] The water undergoes a second heat exchange to obtain hot water.

[0008] The solvent raw material and the hot water exchanged are first heated to obtain steam raw material;

[0009] The heat exchange air is then subjected to a second heating to obtain air feedstock;

[0010] Hydrogen is obtained by electrolyzing the air feedstock and the water vapor feedstock using solid oxides.

[0011] The hydrogen gas is subjected to a third heat exchange to obtain heat-exchanged hydrogen gas; wherein the heat exchange medium of the third heat exchange includes the heat exchange water and / or the solvent raw material;

[0012] Biomass is pyrolyzed to obtain carbon dioxide as a raw material;

[0013] The carbon dioxide feedstock and the heat exchanged hydrogen are used to synthesize methanol to obtain crude methanol product.

[0014] The crude methanol product is subjected to a fourth heat exchange and impurity removal treatment to obtain the methanol product; wherein the heat exchange medium of the fourth heat exchange includes the solvent raw material.

[0015] Optionally, the target temperature for the first heat exchange is 150℃~200℃; and / or

[0016] The target temperature for the second heat exchange is 150℃~200℃; and / or

[0017] The target temperature for the third heat exchange is 200℃~300℃; and / or

[0018] The target temperature for the fourth heat exchange is ≤40℃.

[0019] Optionally, the endpoint temperature of the first heating is 600℃~1000℃; and / or

[0020] The final temperature of the second heating is 600℃~1000℃.

[0021] Optionally, the electrolysis temperature is 600℃~1000℃, the electrolysis voltage is 1V~1.5V, and the electrolysis current density is 800mA / cm². -2 ~1200mA / cm -2 .

[0022] Optionally, the temperature for methanol synthesis is 200℃~300℃, and the pressure for methanol synthesis is 7.5MPa~8.5MPa.

[0023] Optionally, the step of electrolyzing the heat exchange air and the water vapor using solid oxides to obtain hydrogen includes the following steps:

[0024] The heat exchange air and the water vapor are electrolyzed using solid oxides to obtain hydrogen and oxygen, respectively.

[0025] The oxygen is used as the heat exchange medium for both the first and second heat exchanges.

[0026] Secondly, this application provides a system for the coupled preparation of green methanol, the system being adapted to the method described in the first aspect, the system comprising:

[0027] A solid oxide electrolysis unit includes an air feed pipe, a water feed pipe, a solid oxide electrolysis cell, a first heater, and a second heater; the water feed pipe is connected to the air inlet of the first heater to heat water; the air feed pipe is connected to the air inlet of the second heater to heat the heat exchange air; the air outlet of the first heater is connected to the water vapor inlet of the solid oxide electrolysis cell, and the air outlet of the second heater is connected to the air inlet of the solid oxide electrolysis cell;

[0028] The methanol synthesis unit includes a methanol synthesis tower, a hydrogen compressor pump, a solvent feed pipe, and a distillation tower. The solvent feed pipe is connected to the inlet of the methanol synthesis tower to introduce the solvent feed into the methanol synthesis tower. The product outlet of the methanol synthesis tower is connected to the distillation tower to convert crude methanol product into methanol product. The hydrogen outlet of the solid oxide electrolyzer is connected to the inlet of the hydrogen compressor pump, and the outlet of the hydrogen compressor pump is connected to the inlet of the methanol synthesis tower. The methanol synthesis tower is equipped with a carbon dioxide feed pipe for carbon dioxide feeding.

[0029] The heat exchange section includes a first heat exchanger, a second heat exchanger, a third heat exchanger, and a fourth heat exchanger; the first heat exchanger is located between the air feed pipe and the second heater; the second heat exchanger is located between the water feed pipe and the first heater, and the heat exchange medium inlet of the first heat exchanger is connected to the heat exchange medium outlet of the second heat exchanger; the third heat exchanger is located between the solid oxide electrolysis cell and the hydrogen compression pump, and the heat exchange medium outlet of the third heat exchanger is connected to the liquid outlet of the second heat exchanger; the fourth heat exchanger is located between the solvent feed pipe and the methanol synthesis tower.

[0030] Optionally, the heat exchange medium inlet of the first heat exchanger is connected to the heat exchange medium outlet of the second heat exchanger, and the heat exchange medium inlet of the second heat exchanger is connected to the oxygen outlet of the solid oxide electrolysis cell.

[0031] The heat exchange medium inlet of the third heat exchanger is connected to the liquid outlet of the second heat exchanger, and the feed inlet of the third heat exchanger is connected to the hydrogen outlet of the solid oxide electrolysis cell; and / or

[0032] The heat exchange medium inlet of the third heat exchanger is connected to the liquid outlet of the solvent raw material feed pipe.

[0033] Optionally, the heat exchange medium inlet of the fourth heat exchanger is connected to the liquid outlet of the solvent feed pipe; the feed inlet of the fourth heat exchanger is connected to the product outlet of the methanol synthesis tower; the outlet of the fourth heat exchanger is connected to the feed inlet of the distillation tower; the non-condensable vapor outlet of the fourth heat exchanger is connected to the feed inlet of the methanol synthesis tower; and / or

[0034] When the heat exchange medium inlet of the third heat exchanger is connected to the liquid outlet of the solvent raw material feed pipe, the heat exchange medium outlet of the fourth heat exchanger is connected to the heat exchange medium inlet of the third heat exchanger.

[0035] The technical solutions provided in this application have the following advantages compared with the prior art:

[0036] This application provides a method for synthesizing green methanol from methane via electrolytic coupling. Before the electrolysis reaction, the method involves first and second heat exchanges on air and water, respectively. These first and second heat exchanges increase the temperature of the water and air, thereby reducing the temperature and time required for the first and second heating processes, thus lowering the energy consumption burden of heating the raw materials for electrolysis. Furthermore, a third heat exchange is performed on the hydrogen produced by electrolysis. The heat exchange medium for this third heat exchange is either hot water or a solvent. The heat from the hydrogen can be recovered from the hot water or solvent, further increasing its temperature, which in turn further reduces the temperature and time required for the first heating process, thereby lowering the energy consumption burden of the first heating process and improving the energy utilization rate of the electrolysis. Additionally, the crude methanol product from the methanol synthesis is further processed... The fourth heat exchange, where the heat exchange medium includes the solvent feedstock, allows for the recovery of heat from the crude methanol product. This reduces the energy consumption required for heating the solvent feedstock during methanol synthesis. Furthermore, the solvent feedstock after the fourth heat exchange can be used as a feedstock for electrolysis, thus creating a dual-cycle heat recovery process for electrolysis and methanol synthesis. This effectively reduces the energy consumption required for methanol synthesis and improves efficiency. In summary, this method effectively recovers excess heat from the electrolysis process by performing the first and second heat exchanges on the electrolysis feedstock, followed by the third heat exchange on the electrolyzed hydrogen product. Finally, the fourth heat exchange on the crude methanol product effectively recovers excess heat from the methanol product. Therefore, this method can effectively recover heat from both the feedstock and the product through multiple heat exchanges, thereby improving the energy utilization rate of the coupled process. Attached Figure Description

[0037] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0038] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 This application provides a schematic flowchart of a method for preparing green methanol through electrolytic coupling of methane synthesis.

[0040] Figure 2 This application provides a detailed flowchart illustrating a method for preparing green methanol through electrolytic coupling of methane synthesis.

[0041] Figure 3 This is a schematic diagram of the system logic structure for the coupled preparation of green methanol provided in an embodiment of this application;

[0042] Figure 4 This is a schematic diagram of the actual structure of a system for the coupled preparation of green methanol, provided in an embodiment of this application.

[0043] Among them, 1-air feed pipe, 2-water feed pipe, 3-solid oxide electrolysis cell, 4-first heater, 5-second heater, 6-methanol synthesis tower, 7-hydrogen compression pump, 8-solvent feed pipe, 9-distillation tower, 10-first heat exchanger, 11-second heat exchanger, 12-third heat exchanger, 13-fourth heat exchanger. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0045] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range; for example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range; in addition, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0046] In this document, terms such as “comprising” mean “including but not limited to”. Relational terms such as “first” and “second” are used only 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. “And / or” describes the relationship between related objects, indicating that there can be three relationships, for example, A and / or B can mean: A alone, A and B simultaneously, or B alone; where A and B can be singular or plural. “At least one” means one or more, “more” means two or more; “at least one,” “at least one of the following,” or similar expressions refer to any combination of these items, including any combination of single or plural items; for example, “at least one of a, b, or c,” or “at least one of a, b, and c,” can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple. "Parts representation," such as parts by weight or parts by mass, indicates the proportional relationship between components. In the proportional relationships discussed in this article, parameters described by proportion should be understood as the first term of the proportion, following the order of description, while the proportion figures should be understood as the second term. For example, if the mass ratio of substance A, substance B, and substance C is 1:2:3, then substances A, B, and C should correspond one-to-one with the proportion figures in the proportion, i.e., mass of substance A : mass of substance B : mass of substance C.

[0047] = 1:2:3.

[0048] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this article can be purchased from the market or prepared by existing methods.

[0049] Figure 1An exemplary schematic diagram of a method for preparing green methanol by electrolytic coupling of methane is shown in an embodiment of this application;

[0050] like Figure 1 As shown in the embodiments of this application, a method for preparing green methanol by electrolytic coupling of methane is provided, the method comprising:

[0051] S1. The air undergoes a first heat exchange to obtain heat-exchanged air;

[0052] S2. The water undergoes a second heat exchange to obtain hot water;

[0053] S3. The solvent raw material and the hot water exchanged are heated for the first time to obtain steam raw material;

[0054] S4. The heat exchange air is heated a second time to obtain air raw material;

[0055] S5. Electrolyze the air feedstock and the water vapor feedstock using a solid oxide to obtain hydrogen;

[0056] S6. The hydrogen gas is subjected to a third heat exchange to obtain heat-exchanged hydrogen gas; wherein the heat exchange medium of the third heat exchange includes the heat exchange water and / or solvent raw material;

[0057] S7. Pyrolyze biomass to obtain carbon dioxide feedstock;

[0058] S8. The carbon dioxide feedstock and the heat exchanged hydrogen are subjected to methanol synthesis to obtain crude methanol product;

[0059] S9. The crude methanol product is subjected to a fourth heat exchange and impurity removal treatment to obtain the methanol product; wherein the heat exchange medium of the fourth heat exchange includes the solvent raw material.

[0060] It should be noted that the first heat exchange can be a heat exchange between air and oxygen; the second heat exchange can be a heat exchange between water and oxygen; the third heat exchange can be a heat exchange between hydrogen and water, or a heat exchange between hydrogen and solvent raw materials; and the fourth heat exchange can be a heat exchange between water and crude methanol product.

[0061] It should be noted that the first heating can be a steam electric heater, and the second heating can be an air electric heater.

[0062] It should be noted that this impurity removal process can be a distillation process.

[0063] It should be noted that the solvent raw material can be water.

[0064] In some alternative embodiments, the target temperature for the first heat exchange is 150°C to 200°C; and / or

[0065] The target temperature for the second heat exchange is 150℃~200℃; and / or

[0066] The target temperature for the third heat exchange is 200℃~300℃; and / or

[0067] The target temperature for the fourth heat exchanger is ≤40℃;

[0068] In these embodiments, the target temperature of the first heat exchange can be 150°C to 200°C, so that the air passing through the first heat exchange can reach this range, reducing the temperature of the subsequent second heating and thus lowering the energy consumption of the second heating. Similarly, the target temperature of the second heat exchange can be 150°C to 200°C, so that the water passing through the second heat exchange can reach this range, again reducing the temperature of the subsequent first heating and thus lowering the energy consumption of the first heating. Furthermore, the target temperature of the third heat exchange can be 200°C to 300°C, where the hot water recovers the heat from the hydrogen gas through the third heat exchange, effectively recovering the energy of the hydrogen gas produced by electrolysis, thereby improving the energy utilization rate of the coupled process. Finally, the target temperature of the fourth heat exchange can be ≤40°C, where the solvent raw material recovers the energy of the crude methanol product through the fourth heat exchange, effectively recovering the heat from the crude methanol produced by methanol synthesis, and using the heat-exchanged solvent raw material as a feedstock for electrolysis, thereby improving the energy utilization rate of the coupled process.

[0069] It should be noted that, since the material contact time of the first, second, third, and fourth heat exchanges can be controlled cyclically in actual production, and these times vary with the amount of material processed, they are not limited here. The heat exchange time here only needs to be sufficient for the material to reach the target temperature after the first, second, third, and fourth heat exchanges.

[0070] The target temperature for the first heat exchange can be 150℃, 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, 185℃, 190℃, 195℃ or 200℃.

[0071] The target temperature for the second heat exchange can be 150℃, 155℃, 160℃, 165℃, 170℃, 175℃, 180℃, 185℃, 190℃, 195℃ or 200℃.

[0072] The target temperature for the third heat exchange can be 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃ or 300℃.

[0073] In some alternative embodiments, the endpoint temperature of the first heating is 600°C to 1000°C; and / or

[0074] The final temperature of the second heating is 600℃~1000℃;

[0075] In these embodiments, the endpoint temperature of the first heating can be 600℃ to 1000℃. The first heating method can sufficiently heat the heat exchange water to promote complete electrolysis and obtain a large amount of high-temperature hydrogen. This facilitates the subsequent use of a third heat exchange method to increase the temperature of the solvent raw material, effectively recovering the energy of the hydrogen produced during electrolysis, thereby improving the energy utilization rate of the coupled process. Similarly, the endpoint temperature of the second heating can also be 600℃ to 1000℃. The second heating method can sufficiently heat the heat exchange air to promote complete electrolysis and obtain a large amount of high-temperature hydrogen. This facilitates the subsequent use of a third heat exchange method to increase the temperature of the solvent raw material, effectively recovering the energy of the hydrogen produced during electrolysis, thereby improving the energy utilization rate of the coupled process.

[0076] The endpoint temperature of the first heating can be 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃ or 1000℃.

[0077] The endpoint temperature of the second heating can be 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃ or 1000℃.

[0078] It should be noted that the heating time of the first heating and the second heating can be controlled through the circulation pipeline in actual production. Therefore, the specific heating time of the first heating and the second heating cannot be controlled. The heating time of the first heating and the second heating only needs to be enough for the material to reach the corresponding endpoint temperature after the first heating and the second heating.

[0079] In some optional embodiments, the electrolysis temperature is 600℃ to 1000℃, the electrolysis voltage is 1V to 1.5V, and the electrolysis current density is 800mA / cm². -2 ~1200mA / cm -2 ;

[0080] In these embodiments, the electrolysis temperature can be 600°C to 1000°C, the electrolysis voltage can be 1V to 1.5V, and the electrolysis current density can be 800mA / cm². -2 -1200mA / cm -2 This process allows air and water feedstocks to be fully converted into high-temperature hydrogen through electrolysis, facilitating the subsequent increase in the temperature of the solvent feedstock via a third heat exchanger. This effectively recovers the energy from the hydrogen produced during electrolysis, thereby improving the energy utilization rate of the coupled process.

[0081] The electrolysis temperature can be 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, 950℃ or 1000℃.

[0082] The voltage for electrolysis can be 1.0V, 1.1V, 1.2V, 1.3V, 1.4V, or 1.5V.

[0083] The current density for this electrolysis can be 800 mA / cm². -2 850mA / cm -2 900mA / cm -2 950mA / cm -2 100mA / cm -2 1050mA / cm -2 1100mA / cm -2 1150mA / cm -2 Or 1200mA / cm -2 .

[0084] It should be noted that the electrolysis time varies with the amount of material entering the system. Therefore, the electrolysis time only needs to be sufficient to ensure that the air and water raw materials are fully electrolyzed to produce hydrogen and oxygen.

[0085] In some optional embodiments, the temperature for methanol synthesis is 200°C to 300°C, and the pressure for methanol synthesis is 7.5 MPa to 8.5 MPa.

[0086] In these embodiments, the temperature for methanol synthesis can be 200°C to 300°C, and the pressure for methanol synthesis can be 7.5 MPa to 8.5 MPa, so that carbon dioxide feedstock and heat exchange hydrogen are converted into crude methanol product through methanol synthesis.

[0087] The temperature for methanol synthesis can be 200℃, 210℃, 220℃, 230℃, 240℃, 250℃, 260℃, 270℃, 280℃, 290℃ or 300℃.

[0088] The pressure for methanol synthesis can be 7.5 MPa, 7.6 MPa, 7.7 MPa, 7.8 MPa, 7.9 MPa, 8.0 MPa, 8.1 MPa, 8.2 MPa, 8.3 MPa, 8.4 MPa or 8.5 MPa.

[0089] It should be noted that the specific time for methanol synthesis depends on the amount of carbon dioxide feedstock and heat exchange hydrogen added. In actual production, the amount of methanol synthesized from methanol changes in real time to ensure the full reaction of carbon dioxide feedstock and heat exchange hydrogen.

[0090] Figure 2 An exemplary schematic diagram of a detailed process for the electrolytic coupling of methane to prepare green methanol is shown in an embodiment of this application.

[0091] In some alternative implementations, such as Figure 2 As shown, the step of electrolyzing the heat exchange air and water vapor using solid oxides to obtain hydrogen includes the following steps:

[0092] S501. Electrolyze the heat exchange air and the water vapor using solid oxides to obtain hydrogen and oxygen respectively;

[0093] S502. The oxygen is used as the heat exchange medium for the first heat exchange and the second heat exchange;

[0094] In these embodiments, using the oxygen generated by electrolysis as the heat exchange medium for the first and second heat exchanges can, on the one hand, fully recover the heat generated during the electrolysis process, and on the other hand, reduce the energy consumption required for the first and second heating processes, thereby improving the energy utilization rate of the coupled process.

[0095] Figure 3 An exemplary schematic diagram of the system logic structure for the coupled preparation of green methanol provided in an embodiment of this application is shown;

[0096] Figure 4 An exemplary schematic diagram of the actual structure of a system for the coupled preparation of green methanol provided in an embodiment of this application is shown;

[0097] Based on a general inventive concept, such as Figure 3 and Figure 4 As shown, this application provides a system for the coupled preparation of green methanol, the system being adapted to the method, the system comprising:

[0098] The solid oxide electrolysis unit includes an air feed pipe 1, a water feed pipe 2, a solid oxide electrolysis cell 3, a first heater 4, and a second heater 5. The water feed pipe 2 is connected to the air inlet of the first heater 4 to heat the water. The air feed pipe 1 is connected to the air inlet of the second heater 5 to heat the heat exchange air. The air outlet of the first heater 4 is connected to the steam inlet of the solid oxide electrolysis cell 3, and the air outlet of the second heater 5 is connected to the air inlet of the solid oxide electrolysis cell 3.

[0099] The methanol synthesis unit includes a methanol synthesis tower 6, a hydrogen compression pump 7, a solvent feed pipe 8, and a distillation tower 9. The solvent feed pipe 8 is connected to the inlet of the methanol synthesis tower 6 to introduce the solvent feed into the methanol synthesis tower 6. The product outlet of the methanol synthesis tower 6 is connected to the distillation tower 9 to convert crude methanol product into methanol product. The hydrogen outlet of the solid oxide electrolysis cell 3 is connected to the inlet of the hydrogen compression pump 7, and the outlet of the hydrogen compression pump 7 is connected to the inlet of the methanol synthesis tower 6. The methanol synthesis tower 6 is equipped with a carbon dioxide feed pipe for carbon dioxide feeding.

[0100] The heat exchange section includes a first heat exchanger 10, a second heat exchanger 11, a third heat exchanger 12, and a fourth heat exchanger 13. The first heat exchanger 10 is located between the air feed pipe 1 and the second heater 5. The second heat exchanger 11 is located between the water feed pipe 2 and the first heater 4, and the heat exchange medium inlet of the first heat exchanger 10 is connected to the heat exchange medium outlet of the second heat exchanger 11. The third heat exchanger 12 is located between the solid oxide electrolysis cell 3 and the hydrogen compression pump 7, and the heat exchange medium outlet of the third heat exchanger 12 is connected to the liquid outlet of the second heat exchanger 11. The fourth heat exchanger 13 is located between the solvent feed pipe 8 and the methanol synthesis tower 6.

[0101] This coupled system for producing green methanol is designed very comprehensively, covering the entire process from raw material input to final product output. The following is a detailed explanation of the system:

[0102] Air feed pipe 1 is used to introduce air into the system, preparing it for subsequent secondary heating and electrolysis. Water feed pipe 2 is used to introduce water into the system, preparing it for primary heating to generate water vapor. Solid oxide electrolysis cell 3 is the core component of the system, used to electrolyze the air and water vapor after primary and secondary heating to produce hydrogen and oxygen. First heater 4 is used to heat the water entering through water feed pipe 2, converting it into water vapor. Second heater 5 is used to heat the air entering through air feed pipe 1, bringing it to the temperature required for electrolysis.

[0103] Methanol synthesis tower 6 is the main site for methanol synthesis, where hydrogen and carbon dioxide react to produce methanol under the action of a catalyst. Hydrogen compressor pump 7 is used to compress and transport hydrogen produced by electrolysis to methanol synthesis tower 6. Solvent feed pipe 8 is used to regulate the reaction conditions within the methanol synthesis tower or as part of the reaction (e.g., as a solvent or another feedstock participating in the methanol synthesis reaction), primarily for heat exchange rather than direct reaction participation. Distillation tower 9 is used to purify the crude methanol product produced by the methanol synthesis tower to obtain high-quality methanol.

[0104] The first heat exchanger 10, located between the air inlet pipe 1 and the second heater 5, is used to preheat the air entering the second heater 5. The second heat exchanger 11, located between the water inlet pipe 2 and the first heater 4, is used to preheat the water entering the first heater 4. Furthermore, its heat exchange medium is connected to that of the first heat exchanger 10, and its heat exchange process is also connected to the third heat exchanger 12, forming a continuous heat exchange network. The third heat exchanger 12, located between the solid oxide electrolysis cell 3 and the hydrogen compression pump 7, is used to cool the hydrogen produced by electrolysis while recovering heat. The fourth heat exchanger 13, located between the solvent feed pipe 8 and the methanol synthesis tower 6, may be used to preheat the solvent feed and recover heat from the crude methanol product.

[0105] The following is an overview of the system's workflow: Air and water enter the system through air inlet pipe 1 and water inlet pipe 2, respectively. The air and water are then preheated through the first heat exchanger 10 and the second heat exchanger 11 (other heat sources may also be present). The preheated air and water are further heated through the second heater 5 and the first heater 4, respectively. Meanwhile, the solvent raw material enters the first heater 4 through the fourth heat exchanger 13 (other processing steps may exist) to heat the preheated water and convert it into steam. The heated air and steam then enter the solid oxide electrolysis cell 3 for electrolysis to produce hydrogen and oxygen. The hydrogen is then cooled through the third heat exchanger 12 and transported to the methanol synthesis tower 6 via the hydrogen compression pump 7. In the methanol synthesis tower 6, hydrogen and carbon dioxide (which can come from multiple sources, such as biomass pyrolysis) undergo a synthesis reaction to produce crude methanol. Finally, the crude methanol product is purified by passing through the fourth heat exchanger 13 and then through the distillation tower 9 to obtain high-quality methanol.

[0106] The system is implemented based on the above method. The specific steps of the method can be referred to the above embodiments. Since the system adopts some or all of the technical solutions of the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated here.

[0107] It should be noted that the heat exchange medium inlet of the first heat exchanger 10 is connected to the heat exchange medium outlet of the second heat exchanger 11, which can realize continuous heat exchange between the first heat exchanger 10 and the second heat exchanger 11, so as to fully recover the heat of the heat exchange medium.

[0108] In some alternative embodiments, the heat exchange medium inlet of the first heat exchanger 10 is connected to the heat exchange medium outlet of the second heat exchanger 11, and the heat exchange medium inlet of the second heat exchanger 11 is connected to the oxygen outlet of the solid oxide electrolysis cell 3.

[0109] In these embodiments, the heat exchange medium inlet of the first heat exchanger 10 can be connected to the heat exchange medium outlet of the second heat exchanger 11, and the heat exchange medium inlet of the second heat exchanger 11 can be connected to the oxygen outlet of the solid oxide electrolytic cell 3. The oxygen generated by the solid oxide electrolytic cell 3 is used as the heat exchange medium of the first heat exchanger 10 and the second heat exchanger 11 to fully recover the heat of the products generated by the solid oxide electrolytic cell 3 during the electrolysis process, thereby improving the energy utilization rate of the coupled process.

[0110] In some optional embodiments, the heat exchange medium inlet of the third heat exchanger 12 is connected to the liquid outlet of the second heat exchanger 11, and the feed inlet of the third heat exchanger 12 is connected to the hydrogen outlet of the solid oxide electrolysis cell 3; and / or

[0111] The heat exchange medium inlet of the third heat exchanger 12 is connected to the liquid outlet of the solvent raw material feed pipe 8;

[0112] In these embodiments, the heat exchange medium inlet of the third heat exchanger 12 can be connected to the liquid outlet of the second heat exchanger 11, and the feed inlet of the third heat exchanger 12 can be connected to the hydrogen outlet of the solid oxide electrolysis cell 3. The hydrogen produced by the solid oxide electrolysis cell 3 is used as a heat source to heat the water exchanged in the second heat exchanger 11, which can fully recover the heat of the products generated by the solid oxide electrolysis cell 3 during the electrolysis process, thereby improving the energy utilization rate of the coupled process. In addition, the heat exchange medium inlet of the third heat exchanger 12 can also be connected to the liquid outlet of the solvent raw material feed pipe 8, so that the heat of the hydrogen generated by electrolysis can be recovered by using the solvent raw material as a heat exchange medium, thereby further reducing the heating load of the first heater 4 and improving the energy utilization rate of the coupled process.

[0113] It should be noted that there can be two third heat exchangers 12. One third heat exchanger 12 exchanges heat between the hot water coming out of the second heat exchanger 11 and the hydrogen produced by electrolysis, and the other third heat exchanger 12 exchanges heat between the solvent raw material and the hydrogen produced by electrolysis.

[0114] In some optional embodiments, the heat exchange medium inlet of the fourth heat exchanger 13 is connected to the liquid outlet of the solvent feed pipe 8, the feed inlet of the fourth heat exchanger 13 is connected to the product outlet of the methanol synthesis tower 6, and the outlet of the fourth heat exchanger 13 is connected to the feed inlet of the distillation tower 9; the non-condensable vapor outlet of the fourth heat exchanger 13 is connected to the feed inlet of the methanol synthesis tower 6; and / or

[0115] When the heat exchange medium inlet of the third heat exchanger 12 is connected to the liquid outlet of the solvent raw material feed pipe 8, the heat exchange medium outlet of the fourth heat exchanger 13 is connected to the heat exchange medium inlet of the third heat exchanger 12.

[0116] In these embodiments, the heat exchange medium inlet of the fourth heat exchanger 13 can be connected to the liquid outlet of the solvent feed pipe 8, the feed inlet of the fourth heat exchanger 13 can be connected to the product outlet of the methanol synthesis tower 6, and the outlet of the fourth heat exchanger 13 can be connected to the feed inlet of the distillation tower 9. By using the solvent feed pipe as the heat exchange medium of the fourth heat exchanger 13, the heat of the crude methanol product produced by the methanol synthesis tower 6 can be effectively recovered. Furthermore, when the heat exchange medium inlet of the third heat exchanger 12 is connected to the liquid outlet of the solvent feed pipe 8, the heat exchange medium outlet of the fourth heat exchanger 13 can be connected to the... The heat exchange medium inlet of the third heat exchanger 12 can continue to exchange heat with the hydrogen produced by electrolysis after the solvent raw material has been heated, so as to further recover the heat of methanol synthesis and electrolysis and use the recovered heat for the first heating process before electrolysis, thereby improving the energy utilization rate of the coupled process. In addition, the non-condensable steam outlet of the fourth heat exchanger 13 can be connected to the feed inlet of the methanol synthesis tower 6, so that the non-condensable steam component (mainly hydrogen, carbon dioxide, methanol, etc.) of the crude methanol product of the fourth heat exchanger 13 can be returned to the methanol synthesis tower 6 for further recycling, thereby reducing the consumption of raw materials.

[0117] It should be noted that when the heat exchange medium inlet of the third heat exchanger 12 is connected to the liquid outlet of the solvent feed pipe 8, there can be two fourth heat exchangers 13. One fourth heat exchanger 13 recovers the heat of the crude methanol product through the solvent feed, causing the crude methanol product to be converted into a liquid phase and obtain a non-condensable vapor component. The other fourth heat exchanger 13 recovers the crude methanol product that has been converted into a liquid phase through the solvent feed, so as to fully recover the heat of the crude methanol product. The heat exchange medium outlets of both fourth heat exchangers 13 are connected to the heat exchange medium inlet of the third heat exchanger 12, so that the solvent feed after heat exchange in the fourth heat exchanger 13 can be used as the heat exchange medium of the third heat exchanger 12. Finally, it is transported through the third heat exchanger 12 to the first heater 4 to be heated with the hot water and converted into steam feed.

[0118] The present application is further illustrated below with reference to specific embodiments. Experimental methods in the following embodiments that do not specify specific conditions are generally determined according to national / industry standards; if there is no corresponding national / industry standard, they are performed according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0119] Example 1

[0120] like Figure 2 As shown, a method for preparing green methanol by electrolytic coupling of methane includes:

[0121] S1. The air undergoes a first heat exchange to obtain heat-exchanged air;

[0122] S2. The water undergoes a second heat exchange to obtain hot water;

[0123] S3. The hot water is heated for the first time to obtain steam as the raw material;

[0124] S4. The heat exchange air is heated a second time to obtain air raw material.

[0125] S501. Using solid oxides to electrolyze heat exchange air and water vapor to obtain hydrogen and oxygen respectively;

[0126] S502. Oxygen is used as the heat exchange medium for the first and second heat exchanges;

[0127] S6. Perform a third heat exchange on the hydrogen gas to obtain heat-exchanged hydrogen gas; wherein, the heat exchange medium of the third heat exchange includes heat exchange water;

[0128] S7. Pyrolyze biomass to obtain carbon dioxide feedstock;

[0129] S8. Methanol is synthesized from solvent raw material, carbon dioxide raw material and heat exchange hydrogen to obtain crude methanol product;

[0130] S9. The crude methanol product is subjected to a fourth heat exchange and impurity removal process to obtain the methanol product; wherein the heat exchange medium of the fourth heat exchange includes solvent raw materials.

[0131] The target temperature for the first heat exchange is 180℃;

[0132] The target temperature for the second heat exchange is 180℃;

[0133] The target temperature for the third heat exchange is 250℃;

[0134] The target temperature for the fourth heat exchange is 40℃.

[0135] The final temperature of the first heating cycle is 800℃;

[0136] The final temperature of the second heating is 800℃.

[0137] The electrolysis temperature was 800℃, the electrolysis voltage was 1V, and the electrolysis current density was 1000mA / cm². -2 .

[0138] The temperature for methanol synthesis is 250℃, and the pressure for methanol synthesis is 8.0MPa.

[0139] Example 2

[0140] Based on the content disclosed in Example 1, the following modifications are made:

[0141] The target temperature for the first heat exchange is 150℃;

[0142] The target temperature for the second heat exchange is 150℃;

[0143] The target temperature for the third heat exchange is 200℃;

[0144] The target temperature for the fourth heat exchange is 40℃.

[0145] The final temperature of the first heating cycle is 600℃;

[0146] The final temperature of the second heating is 600℃.

[0147] The electrolysis temperature was 600℃, the electrolysis voltage was 1.5V, and the electrolysis current density was 800mA / cm². -2 .

[0148] The temperature for methanol synthesis is 200℃, and the pressure for methanol synthesis is 7.5MPa.

[0149] Example 3

[0150] Based on the content disclosed in Example 1, the following modifications are made:

[0151] The target temperature for the first heat exchange is 200℃;

[0152] The target temperature for the second heat exchange is 200℃;

[0153] The target temperature for the third heat exchange is 300℃;

[0154] The target temperature for the fourth heat exchange is 40℃.

[0155] The final temperature of the first heating cycle is 1000℃;

[0156] The final temperature of the second heating is 1000℃.

[0157] The electrolysis temperature was 1000℃, the electrolysis voltage was 1V, and the electrolysis current density was 1200mA / cm². -2 .

[0158] The temperature for methanol synthesis is 300℃, and the pressure for methanol synthesis is 8.5MPa.

[0159] Example 4

[0160] Based on the method disclosed in Example 1, a further related system was designed:

[0161] like Figure 3 and Figure 4 As shown, a system for the coupled preparation of green methanol, and a system adaptation method, include:

[0162] The solid oxide electrolysis unit includes an air feed pipe 1, a water feed pipe 2, a solid oxide electrolysis cell 3, a first heater 4, and a second heater 5. The water feed pipe 2 is connected to the air inlet of the first heater 4 to heat the water. The air feed pipe 1 is connected to the air inlet of the second heater 5 to heat the heat exchange air. The air outlet of the first heater 4 is connected to the steam feed inlet of the solid oxide electrolysis cell 3, and the air outlet of the second heater 5 is connected to the air feed inlet of the solid oxide electrolysis cell 3.

[0163] The methanol synthesis unit includes a methanol synthesis tower 6, a hydrogen compression pump 7, a solvent feed pipe 8, and a distillation tower 9. The solvent feed pipe 8 is connected to the inlet of the methanol synthesis tower 6 to introduce the solvent feed into the methanol synthesis tower 6. The product outlet of the methanol synthesis tower 6 is connected to the distillation tower 9 to convert the crude methanol product into methanol product. The hydrogen outlet of the solid oxide electrolysis cell 3 is connected to the inlet of the hydrogen compression pump 7, and the outlet of the hydrogen compression pump 7 is connected to the inlet of the methanol synthesis tower 6. The methanol synthesis tower 6 is equipped with a carbon dioxide feed pipe for carbon dioxide feeding.

[0164] The heat exchange section includes a first heat exchanger 10, a second heat exchanger 11, a third heat exchanger 12, and a fourth heat exchanger 13. The first heat exchanger 10 is located between the air feed pipe 1 and the second heater 5. The second heat exchanger 11 is located between the water feed pipe 2 and the first heater 4, and the heat exchange medium inlet of the first heat exchanger 10 is connected to the heat exchange medium outlet of the second heat exchanger 11. The third heat exchanger 12 is located between the solid oxide electrolysis cell 3 and the hydrogen compression pump 7, and the heat exchange medium outlet of the third heat exchanger 12 is connected to the air outlet of the second heat exchanger 11. The fourth heat exchanger 13 is located between the solvent feed pipe 8 and the methanol synthesis tower 6.

[0165] The heat exchange medium inlet of the first heat exchanger 10 is connected to the heat exchange medium outlet of the second heat exchanger 11, and the heat exchange medium inlet of the second heat exchanger 11 is connected to the oxygen outlet of the solid oxide electrolysis cell 3.

[0166] The heat exchange medium inlet of the third heat exchanger 12 is connected to the liquid outlet of the second heat exchanger 11, and the feed inlet of the third heat exchanger 12 is connected to the hydrogen outlet of the solid oxide electrolysis cell 3.

[0167] The heat exchange medium inlet of the fourth heat exchanger 13 is connected to the liquid outlet of the solvent feed pipe 8, the feed inlet of the fourth heat exchanger 13 is connected to the product outlet of the methanol synthesis tower 6, and the outlet of the fourth heat exchanger 13 is connected to the feed inlet of the distillation tower 9; the heat exchange medium outlet of the fourth heat exchanger 13 is connected to the feed inlet of the first heater 4, and the outlet of the fourth heat exchanger 13 is connected to the feed inlet of the methanol synthesis tower 6.

[0168] Comparative Example 1

[0169] Based on the content disclosed in Example 1, the following modifications are made:

[0170] Instead of using the first, second, third, and fourth heat exchangers, the traditional methanol synthesis method is used.

[0171] Comparative Example 2

[0172] Based on the content disclosed in Example 1, the following modifications are made:

[0173] The first and second heat exchangers are not used.

[0174] Comparative Example 3

[0175] Based on the content disclosed in Example 1, the following modifications are made:

[0176] The third and fourth heat exchangers are not used.

[0177] Relevant experimental and effect data:

[0178] The fuel consumption of the entire method in Comparative Example 1 was 100%. Under the condition that the material ratio and other operating conditions were the same, the fuel consumption of each embodiment and the comparative example was statistically analyzed. The statistically analyzed fuel consumption was compared with that of Comparative Example 1. The fuel consumption rate was calculated with the fuel consumption of Comparative Example 1 as the denominator and the fuel consumption of each method as the numerator. The energy utilization rate was calculated using the following formula: Energy utilization rate = 1 - Fuel consumption rate. The results are shown in Table 1.

[0179] Table 1 shows the energy efficiency achieved by the methods in each embodiment and comparative example.

[0180]

[0181]

[0182] As shown in Table 1, the method for preparing green methanol by electrolytic coupling of methane provided in this application effectively recovers the heat of raw materials and products through multiple heat exchange processes, thereby improving the energy utilization rate of the coupling process to 20% to 30%. In addition, Comparative Examples 2 and 3 show that if the first, second, third, and fourth heat exchangers are not used, the energy utilization rate of the entire method will be significantly affected.

[0183] In addition, the system for preparing green methanol by electrolytic coupling of methane provided in the embodiments of this application has been found through actual production tests to have a single-pass methanol conversion rate of 40% to 55%. After running the system in a cycle for a period of time, the total methanol conversion rate can be increased to 99%.

[0184] In summary, the present application provides a method for the electrolytic coupling of methane to produce green methanol. This method effectively recovers excess heat from the electrolysis process by performing a first and second heat exchange on the electrolyzed raw materials, followed by a third heat exchange on the electrolyzed hydrogen product. Finally, a fourth heat exchange on the crude methanol product effectively recovers excess heat from the methanol product. Therefore, this method effectively recovers heat from both the raw materials and the product through multiple heat exchange processes, thereby improving the energy utilization rate of the coupling process.

[0185] In addition, this application provides a method for preparing green methanol by electrolytic coupling of methane. This method avoids energy waste and reduces the heat load of heating the raw materials before electrolysis by using multiple heat exchange methods, thereby improving the efficiency and economy of electrolytic hydrogen production.

[0186] In addition, this application provides a method for preparing green methanol by electrolytic coupling of methane synthesis. Based on the coupling of electrolysis and methanol synthesis, this method can effectively avoid the emission of harmful gases such as sulfur and nitrogen oxides in the traditional methanol synthesis process. Furthermore, this method is expected to reduce carbon emissions by 3.44 tons for every ton of methanol produced, achieving green production.

[0187] Furthermore, this application provides a system for the electrolytic coupling of methane synthesis to prepare green methanol. This system does not require the addition of large-scale equipment or devices. It only requires the construction of multiple heaters and pipelines in the original coupling system. The relevant system can be modified at a lower cost to save production costs.

[0188] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed in this application.

Claims

1. A method for preparing green methanol by electrolytic coupling of methane, the method comprising: The air undergoes a first heat exchange to obtain heat-exchanged air; The water undergoes a second heat exchange to obtain hot water. The solvent raw material and the hot water exchanged are first heated to obtain steam raw material; The heat exchange air is then subjected to a second heating to obtain air feedstock; Hydrogen is obtained by electrolyzing the air feedstock and the water vapor feedstock using solid oxides. The hydrogen gas is subjected to a third heat exchange to obtain heat-exchanged hydrogen gas; wherein the heat exchange medium of the third heat exchange includes the heat exchange water and / or the solvent raw material; Biomass is pyrolyzed to obtain carbon dioxide as a raw material; The carbon dioxide feedstock and the heat exchanged hydrogen are used to synthesize methanol to obtain crude methanol product. The crude methanol product is subjected to a fourth heat exchange and impurity removal treatment to obtain the methanol product; wherein, the heat exchange medium of the fourth heat exchange includes the solvent raw material.

2. The method according to claim 1, wherein the target temperature of the first heat exchange is 150°C to 200°C; and / or The target temperature for the second heat exchange is 150℃~200℃; and / or The target temperature for the third heat exchange is 200℃~300℃; and / or The target temperature for the fourth heat exchange is ≤40℃.

3. The method according to claim 1, wherein the endpoint temperature of the first heating is 600℃~1000℃; and / or The final temperature of the second heating is 600℃~1000℃.

4. The method according to claim 1, wherein the electrolysis temperature is 600℃~1000℃, the electrolysis voltage is 1V~1.5V, and the electrolysis current density is 800mA / cm². -2 ~1200mA / cm -2 .

5. The method according to claim 1, wherein the temperature for methanol synthesis is 200℃~300℃, and the pressure for methanol synthesis is 7.5MPa~8.5MPa.

6. The method according to claim 1, wherein the step of electrolyzing the heat exchange air and the water vapor using a solid oxide to obtain hydrogen includes the following steps: The heat exchange air and the water vapor are electrolyzed using solid oxides to obtain hydrogen and oxygen, respectively. The oxygen is used as the heat exchange medium for both the first and second heat exchanges.

7. A system for coupled preparation of green methanol, said system being adapted to the method of any one of claims 1 to 6, said system comprising: The solid oxide electrolysis unit includes an air feed pipe (1), a water feed pipe (2), a solid oxide electrolysis cell (3), a first heater (4), and a second heater (5); the water feed pipe (2) is connected to the air inlet of the first heater (4) to heat the water; the air feed pipe (1) is connected to the air inlet of the second heater (5) to heat the heat exchange air; the air outlet of the first heater (4) is connected to the water vapor inlet of the solid oxide electrolysis cell (3), and the air outlet of the second heater (5) is connected to the air inlet of the solid oxide electrolysis cell (3); The methanol synthesis unit includes a methanol synthesis tower (6), a hydrogen compression pump (7), a solvent feed pipe (8), and a distillation tower (9). The solvent feed pipe (8) is connected to the inlet of the methanol synthesis tower (6) to introduce the solvent feed into the methanol synthesis tower (6). The product outlet of the methanol synthesis tower (6) is connected to the distillation tower (9) to convert crude methanol product into methanol product. The hydrogen outlet of the solid oxide electrolysis cell (3) is connected to the inlet of the hydrogen compression pump (7), and the outlet of the hydrogen compression pump (7) is connected to the inlet of the methanol synthesis tower (6). The methanol synthesis tower (6) is equipped with a carbon dioxide feed pipe for carbon dioxide feeding. The heat exchange section includes a first heat exchanger (10), a second heat exchanger (11), a third heat exchanger (12), and a fourth heat exchanger (13); the first heat exchanger (10) is located between the air feed pipe (1) and the second heater (5); the second heat exchanger (11) is located between the water feed pipe (2) and the first heater (4), and the heat exchange medium inlet of the first heat exchanger (10) is connected to the heat exchange medium outlet of the second heat exchanger (11); the third heat exchanger (12) is located between the solid oxide electrolysis cell (3) and the hydrogen compression pump (7), and the heat exchange medium outlet of the third heat exchanger (12) is connected to the liquid outlet of the second heat exchanger (11); the fourth heat exchanger (13) is located between the solvent raw material feed pipe (8) and the methanol synthesis tower (6).

8. The system according to claim 7, wherein the heat exchange medium inlet of the first heat exchanger (10) is connected to the heat exchange medium outlet of the second heat exchanger (11), and the heat exchange medium inlet of the second heat exchanger (11) is connected to the oxygen outlet of the solid oxide electrolysis cell (3).

9. The system according to claim 7, wherein the heat exchange medium inlet of the third heat exchanger (12) is connected to the liquid outlet of the second heat exchanger (11), and the feed inlet of the third heat exchanger (12) is connected to the hydrogen outlet of the solid oxide electrolysis cell (3); and / or The heat exchange medium inlet of the third heat exchanger (12) is connected to the liquid outlet of the solvent raw material feed pipe (8).

10. The system according to claim 7, wherein the heat exchange medium inlet of the fourth heat exchanger (13) is connected to the liquid outlet of the solvent feed pipe (8), the feed inlet of the fourth heat exchanger (13) is connected to the product outlet of the methanol synthesis tower (6), and the outlet of the fourth heat exchanger (13) is connected to the feed inlet of the distillation tower (9); the non-condensable vapor outlet of the fourth heat exchanger (13) is connected to the feed inlet of the methanol synthesis tower (6); and / or When the heat exchange medium inlet of the third heat exchanger (12) is connected to the liquid outlet of the solvent raw material feed pipe (8), the heat exchange medium outlet of the fourth heat exchanger (13) is connected to the heat exchange medium inlet of the third heat exchanger (12).

Images