A system and method for electrocatalytic conversion of carbon dioxide

Abstract

The application provides a carbon dioxide electrocatalytic conversion system and method, which comprises the following steps: a CO2 pressurization system pressurizes carbon dioxide generated by a fossil energy utilization system; a renewable energy power generation system generates green electricity by using renewable energy; a heat medium circulation system uses industrial waste heat generated by the fossil energy utilization system, superheated steam or green electricity generated by the renewable energy power generation system to provide heat for the heat medium, and heats the heat medium to a preset temperature; a carbon dioxide electrocatalytic conversion unit electrocatalytically converts the pressurized CO2; and a cathode product treatment system and an anode product treatment system respectively treat cathode products and anode products of the carbon dioxide electrocatalytic conversion unit, so that the cathode products and the anode products are recycled. By increasing the temperature and pressure of the electrolysis reaction, the carbon dioxide treatment capacity and conversion rate are greatly improved, the reaction speed is increased, the cell pressure is reduced, and the energy conversion efficiency is improved by more than 30% compared with the prior art.

Description

Technical Field

[0001] This invention relates to the field of green energy application technology, and more specifically, to a carbon dioxide electrocatalytic conversion system and method. Background Technology

[0002] Currently, in my country's energy structure, fossil fuels account for 84% of carbon emissions, while non-fossil fuels account for 16%. However, renewable energy sources such as solar and wind power are highly volatile and unstable due to seasonal and temporal influences. As a result, they face difficulties in grid connection and utilization, leading to low utilization rates and frequent issues of wind and solar power curtailment.

[0003] How can we treat carbon dioxide emitted during fossil fuel use as a carbon resource, while simultaneously converting waste electricity generated from renewable energy sources into essential carbon-based products? This involves using renewable energy sources such as wind, solar, geothermal, and tidal power to generate electricity for the electrocatalytic conversion of carbon dioxide, achieving the conversion and storage of electrical energy into chemical energy. This reduces the instability of high-proportion renewable energy grid connections, enables green substitution of traditional fuels and chemicals, and provides a new means for renewable electricity storage. The resulting carbon-based products can serve as a chemical energy storage medium, significantly impacting global CO2 emissions. However, existing carbon dioxide electrocatalytic conversion processes have relatively low overall technological maturity. Systems operate at ambient temperature and pressure, with high electrolytic cell pressure, high power consumption, slow reaction times, low carbon dioxide conversion rates (15-20%), and low electrolytic cell processing capacity. Summary of the Invention

[0004] In view of this, the present invention proposes a carbon dioxide electrocatalytic conversion system and method, aiming to solve the problem of low carbon dioxide conversion rate in existing carbon dioxide electrocatalytic conversion processes.

[0005] In one aspect, the present invention proposes a carbon dioxide electrocatalytic conversion system, comprising: a heat medium circulation system, a CO2 pressurization system, a carbon dioxide electrocatalytic conversion unit, a cathode product treatment system, and an anode product treatment system; wherein,

[0006] The inlet of the CO2 pressurization system is connected to the first outlet of the fossil energy utilization system, in order to pressurize the CO2 generated by the fossil energy utilization system.

[0007] The first inlet, second inlet, and third inlet of the carbon dioxide electrocatalytic conversion unit are respectively connected to the outlet of the CO2 pressurization system, the first green electricity outlet of the renewable energy power generation system, and the first outlet of the heat medium circulation system, so as to utilize the pressurized carbon dioxide, the electrical energy generated by the renewable energy power generation system, and the heat energy generated by the heat medium circulation system to carry out the electrocatalytic conversion reaction of carbon dioxide.

[0008] The inlet of the cathode product treatment system is connected to the first outlet of the carbon dioxide electrocatalytic conversion unit to treat the cathode products of the carbon dioxide electrocatalytic conversion unit; the first inlet of the carbon dioxide electrocatalytic conversion unit is connected to the CO2 circulating gas outlet of the cathode product treatment system to recycle the CO2 circulating gas and improve the carbon dioxide conversion rate.

[0009] The inlet of the anode product treatment system is connected to the second outlet of the carbon dioxide electrocatalytic conversion unit for treating the anode products of the carbon dioxide electrocatalytic conversion unit; the fourth inlet of the carbon dioxide electrocatalytic conversion unit is connected to the electrolyte outlet of the anode product treatment system for recycling the electrolyte.

[0010] Furthermore, in the aforementioned carbon dioxide electrocatalytic conversion system, the carbon dioxide electrocatalytic conversion unit is composed of multiple single cells connected in parallel or series; wherein, each single cell includes: a cathode plate, an anode plate, and a gas diffusion layer, a cathode catalyst layer, an anion exchange membrane, an anode catalyst layer, and a titanium mesh support structure arranged sequentially from the cathode plate to the anode plate; the gas diffusion layer, cathode catalyst layer, anion exchange membrane, anode catalyst layer, and titanium mesh support structure constitute a membrane electrode assembly; wherein,

[0011] A cathode flow channel region is provided on the side of the cathode plate near the gas diffusion layer, and a cathode heat medium flow channel region is formed on the upper surface of the cathode plate. The cathode heat medium flow channel region is formed by sequentially splicing and laying multiple sets of first vertical pipe assemblies and first horizontal pipe assemblies. The first vertical pipe assembly includes a first vertical pipe and a second vertical pipe arranged in parallel, with the first vertical pipe and the second vertical pipe respectively located near and away from the gas diffusion layer. A first heat medium inlet and a first heat medium outlet are respectively formed at both ends of the cathode heat medium flow channel region.

[0012] An anode flow channel area is provided on the side of the anode plate near the titanium mesh support structure. An anode heat medium flow channel area is formed on the upper surface of the anode plate. The anode heat medium flow channel area is formed by sequentially splicing and laying multiple sets of second vertical pipe assemblies and second horizontal pipe assemblies. The second vertical pipe assembly includes a third vertical pipe and a fourth vertical pipe arranged in parallel. The third vertical pipe and the fourth vertical pipe are respectively located near and away from the titanium mesh support structure. A second heat medium inlet and a second heat medium outlet are respectively formed at both ends of the anode heat medium flow channel area.

[0013] Furthermore, in the aforementioned carbon dioxide electrocatalytic conversion system, a gas inlet and a gas outlet are respectively provided at both ends of the cathode flow channel region. This allows pressurized CO2 to flow in through the gas inlet, where a gas-liquid-solid three-phase catalytic reaction occurs on the membrane electrode assembly, yielding reduction products, which are then discharged through the gas outlet. The gas outlet is located on the same side as the first heat medium inlet, and the gas inlet is located on the same side as the first heat medium outlet, ensuring that the flow direction of the heat medium is opposite to the flow direction of the carbon dioxide gas, thus achieving countercurrent heat exchange; and / or

[0014] The anode flow channel region has an electrolyte inlet and a product outlet at each end, respectively, so that pressurized electrolyte enters through the electrolyte inlet and undergoes a catalytic reaction on the anode catalyst layer to obtain an oxidation product mainly composed of oxygen, which is discharged through the product outlet. The product outlet and the second heat medium inlet are on the same side, and the electrolyte inlet and the second heat medium outlet are on the same side, so as to ensure that the flow direction of the heat medium is opposite to that of the electrolyte, so as to perform countercurrent heat exchange.

[0015] Furthermore, in the above-mentioned carbon dioxide electrocatalytic conversion system, the size of the cathode flow channel region matches the size of the membrane electrode assembly; the flow channel of the cathode flow channel region is serpentine, U-shaped, or a hybrid type; and / or the size of the anode flow channel region matches the size of the anode catalyst layer and the titanium mesh support structure; the flow channel of the anode flow channel region is serpentine, U-shaped, or a hybrid type.

[0016] Furthermore, in the above-mentioned carbon dioxide electrocatalytic conversion system, the cathode plate is a graphite plate; and / or the anode plate is a metal plate.

[0017] Furthermore, in the above-mentioned carbon dioxide electrocatalytic conversion system, the length of the first vertical pipe is more than three times the length of the second vertical pipe; and / or the length of the third vertical pipe is more than three times the length of the fourth vertical pipe; and / or the length of the third vertical pipe is 1 / 4 to 1 / 2 of the length of the first vertical pipe.

[0018] Furthermore, in the above-mentioned carbon dioxide electrocatalytic conversion system, the length of the first vertical pipe is more than 5 times its diameter; and / or the length of the third vertical pipe is more than 5 times its diameter.

[0019] Furthermore, in the aforementioned carbon dioxide electrocatalytic conversion system, the cathode product processing system includes: a cathode product cooler, a gas-liquid separator, and a cathode product circulation unit; wherein,

[0020] The inlet of the cathode product cooler is connected to the first outlet of the carbon dioxide electrocatalytic conversion unit to cool the cathode product of the carbon dioxide electrocatalytic conversion unit; the inlet of the gas-liquid separator is connected to the outlet of the cathode product cooler to separate the gas phase and liquid phase in the cathode product.

[0021] The gas phase outlet of the gas-liquid separator is connected to the inlet of the cathode product circulation unit to transport the gas phase substances in the cathode product to the cathode product circulation unit.

[0022] The outlet of the cathode product recycling unit is connected to the first inlet of the carbon dioxide electrocatalytic conversion unit to transport the cathode product to the cathode area for recycling.

[0023] Furthermore, in the aforementioned carbon dioxide electrocatalytic conversion system, the anode product processing system includes: an anode product cooler, an oxygen separator, and an electrolyte circulation and pressurization pump; wherein,

[0024] The inlet of the anode product cooler is connected to the second outlet of the carbon dioxide electrocatalytic conversion unit to cool the anode product of the carbon dioxide electrocatalytic conversion unit; the inlet of the oxygen separator is connected to the outlet of the anode product cooler to separate the oxygen from the anode product and output it as a by-product.

[0025] The inlet of the electrolyte circulation pressurization pump is connected to the outlet of the oxygen separator to pressurize the electrolyte separated by the oxygen separator; the outlet of the electrolyte circulation pressurization pump is connected to the second inlet of the carbon dioxide electrocatalytic conversion unit to transport the pressurized electrolyte to the anode area of ​​the carbon dioxide electrocatalytic conversion unit for recycling.

[0026] Furthermore, the aforementioned carbon dioxide electrocatalytic conversion system also includes: an intake air mixing system; wherein,

[0027] The first and second inlets of the air intake mixing system are respectively connected to the outlet of the CO2 pressurization system and the outlet of the cathode product treatment system. The outlet of the air intake mixing system is connected to the first inlet of the carbon dioxide electrocatalytic conversion unit, so as to mix the pressurized CO2 and the circulating gas generated by the carbon dioxide electrocatalytic conversion unit and then transport them to the carbon dioxide electrocatalytic conversion unit.

[0028] The carbon dioxide electrocatalytic conversion system of this invention pressurizes CO2 from the fossil energy utilization system and delivers it to the carbon dioxide electrocatalytic conversion unit. Green electricity is provided by a renewable energy power generation system to carry out the electrocatalytic conversion reaction. Simultaneously, a heat medium circulation system provides heat energy, increasing the temperature and pressure of the electrocatalytic conversion reaction, thus significantly improving the carbon dioxide processing capacity and conversion rate. The cathode product treatment system enables the recycling of CO2 circulating gas, further improving the CO2 conversion rate. The anode product treatment system enables the recycling of electrolyte, reducing electrolyte consumption.

[0029] On the other hand, the present invention also proposes a carbon dioxide electrocatalytic conversion method, comprising: a CO2 pressurization system pressurizing the carbon dioxide generated by the fossil energy utilization system to obtain CO2 at a preset pressure; a renewable energy power generation system using renewable energy to generate green electricity; and a heat medium circulation system using industrial waste heat, superheated steam or green electricity generated by the fossil energy utilization system to provide heat to the heat medium, heating the heat medium to a preset temperature.

[0030] The carbon dioxide electrocatalytic conversion unit performs electrocatalytic conversion on the pressurized CO2. The cathode product treatment system and the anode product treatment system respectively treat the cathode product and the anode product of the carbon dioxide electrocatalytic conversion unit to achieve the recycling of the cathode product and the anode product.

[0031] Furthermore, in the above-mentioned carbon dioxide electrocatalytic conversion method, the preset pressure is 0.5-3.5 MPa; the preset temperature is 70-130℃.

[0032] Furthermore, in the above-mentioned carbon dioxide electrocatalytic conversion method, the electrochemical reactions occurring in the carbon dioxide electrocatalytic conversion unit are as follows:

[0033] Cathode side: CO2 + H2O + ne – → CO / C2H4 / C2H6O + OH -

[0034] 2H₂O + 2e⁻ → H₂ + 2OH⁻ -

[0035] Anode side: 2OH - → O2 + 2H + + 2e – .

[0036] Furthermore, in the above-mentioned carbon dioxide electrocatalytic conversion method, the temperature of a single cell in the carbon dioxide electrocatalytic conversion unit is 60-120℃; the reaction pressure in the cathode region of the single cell is 0.5-3MPa, the reaction pressure in the anode region is 0.1-2MPa, and the pressure difference between the cathode region and the anode region is 0.4-1MPa.

[0037] The carbon dioxide electrocatalytic conversion method provided by this invention pressurizes the upstream carbon dioxide and delivers it to the carbon dioxide electrocatalytic conversion unit. By controlling the temperature of the carbon dioxide electrocatalytic reaction, the performance of the ion exchange membrane is improved, the rate of carbon dioxide electrocatalytic reduction reaction is increased, the single-pass conversion rate of carbon dioxide is improved, the cell pressure of the electrolysis system is reduced, and the power consumption is reduced, thus greatly increasing the efficiency of the carbon dioxide electrocatalytic conversion system. Attached Figure Description

[0038] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0039] Figure 1 This is a structural block diagram of the carbon dioxide electrocatalytic conversion system provided in an embodiment of the present invention;

[0040] Figure 2 This is a schematic diagram of the structure of a single cell in the carbon dioxide electrocatalytic conversion system provided in an embodiment of the present invention. Detailed Implementation

[0041] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0042] System Implementation Example:

[0043] See Figure 1The carbon dioxide electrocatalytic conversion system of this invention includes: a heat medium circulation system 10, a CO2 pressurization system 20, a carbon dioxide electrocatalytic conversion unit 30, a cathode product treatment system 40, and an anode product treatment system 50; wherein, the inlet of the CO2 pressurization system 20 is connected to the first outlet of the fossil energy utilization system 60 to pressurize the CO2 generated by the fossil energy utilization system 60; the first inlet, second inlet, and third inlet of the carbon dioxide electrocatalytic conversion unit 30 are respectively connected to the outlet of the CO2 pressurization system 20, the first green electricity outlet of the renewable energy power generation system 70, and the first outlet of the heat medium circulation system 10, to utilize the pressurized carbon dioxide, the electrical energy generated by the renewable energy power generation system 70, and the heat energy generated by the heat medium circulation system 10 to carry out the electrocatalytic conversion reaction of carbon dioxide;

[0044] The inlet of the cathode product treatment system 40 is connected to the first outlet of the carbon dioxide electrocatalytic conversion unit 30 to treat the cathode product e of the carbon dioxide electrocatalytic conversion unit 30; the first inlet of the carbon dioxide electrocatalytic conversion unit 30 is connected to the CO2 circulating gas outlet of the cathode product treatment system 40 to recycle the CO2 circulating gas and improve the carbon dioxide conversion rate.

[0045] The inlet of the anode product treatment system 50 is connected to the second outlet of the carbon dioxide electrocatalytic conversion unit 30 to treat the anode product f of the carbon dioxide electrocatalytic conversion unit 30; the fourth inlet of the carbon dioxide electrocatalytic conversion unit 30 is connected to the outlet of the anode product treatment system 50 to recycle the electrolyte.

[0046] Specifically, the fossil energy utilization system 60 includes a coal-fired power generation system, an iron and steel smelting furnace and a coking and chemical unit, a cement calcining furnace, a building materials smelting furnace, and a coal chemical, petrochemical, and natural gas chemical conversion furnace. These systems generate hot flue gas containing carbon dioxide. After purification, cooling, and carbon capture, high-concentration carbon dioxide is obtained. The carbon dioxide is then transported to the CO2 pressurization system 20 for pressurization to obtain CO2 gas with a pressure of 0.5-3.5 MPa.

[0047] In this embodiment, it may further include an intake mixing system 80; wherein the first inlet and the second inlet of the intake mixing system 80 are respectively connected to the outlet of the CO2 pressurization system 20 and the outlet of the cathode product treatment system 40, and the outlet of the intake mixing system 80 is connected to the first inlet of the carbon dioxide electrocatalytic conversion unit 30, for mixing the pressurized CO2 and the circulating gas generated by the carbon dioxide electrocatalytic conversion unit 30 and then conveying them to the carbon dioxide electrocatalytic conversion unit 30. That is, in this embodiment, the two inlets of the intake mixing system 80 are respectively connected to the outlet of the CO2 pressurization system 20 and the outlet of the product circulation unit of the cathode product treatment system 40, so as to mix the CO2 from the fossil energy utilization system 60 and the circulating CO2 from the cathode product treatment system 40 and then convey them to the carbon dioxide electrocatalytic conversion unit 30.

[0048] The renewable energy power generation system 70 includes renewable energy power generation equipment that does not produce carbon emissions, such as solar, hydropower, wind power, geothermal energy, and tidal energy, and can be a single energy source or a combination thereof. The electricity generated from various forms is converted into direct current by a power conversion system, which can be used in the subsequent carbon dioxide electrocatalytic conversion unit 30 and the heat medium circulation system 10.

[0049] The heat transfer medium circulation system 10 uses heat transfer oil or superheated steam as the heat transfer medium. The system includes a heat transfer oil heating unit and a heat transfer oil circulation pump. Industrial waste heat or superheated steam generated by the fossil energy utilization system 60 is used for indirect contact heat exchange with the heat transfer oil medium in the heating unit. Alternatively, green electricity generated by a renewable energy system can be used to electrically heat the heat transfer oil in the heating unit. Specifically, this can be done in the form of a partition wall heat exchanger, with the heat transfer oil flowing through the tube side and the shell side through which waste heat medium (waste flue gas or superheated steam) generated by the fossil energy utilization system 60 is introduced. Alternatively, it can be configured as an electric heater, with electric heating rods installed in the outer chamber of the heating unit to indirectly heat the heat transfer oil in the inner chamber. The heated heat transfer oil is then sent to the carbon dioxide electrocatalytic conversion unit 30 to provide heat. After cooling, the heat transfer oil is returned to the heating unit via the heat transfer oil circulation pump to continue circulating and increasing its temperature.

[0050] In specific implementation, the first inlet of the heat medium circulation system 10 is connected to the second outlet of the fossil energy utilization system 60 to heat the heat medium using industrial waste heat or superheated steam generated by the fossil energy utilization system 60; and / or the second inlet of the heat medium circulation system 10 is connected to the second green electricity outlet of the renewable energy power generation system 70 to heat the heat medium using green electricity generated by the renewable energy power generation system 70.

[0051] The heat medium circulation system 10, which uses superheated steam as the heat medium, is heated by industrial waste heat or green electricity and then used as the heat source for the carbon dioxide electrocatalytic conversion unit 30.

[0052] The three inlets of the carbon dioxide electrocatalytic conversion unit 30 are respectively connected to the outlet of the CO2 pressurization system 20, the first green electricity outlet of the renewable energy power generation system 70, and the first outlet of the heat medium circulation system 10, so as to carry out the electrocatalytic conversion reaction of pressurized CO2 under the action of electrical energy and heat energy. Simultaneously, the inlet of the cathode product treatment system 40 is connected to the first outlet of the carbon dioxide electrocatalytic conversion unit 30, and the CO2 circulating gas outlet of the cathode product treatment system 40 is connected to the first inlet of the carbon dioxide electrocatalytic conversion unit 30, so as to realize the treatment and recycling of the product in cathode region e. Since the reduction reaction of CO2 occurs in cathode region e of the carbon dioxide electrocatalytic conversion unit 30, it is beneficial to improve the conversion rate of carbon dioxide by supplying the CO2 circulating gas and the CO2 pressurized by the CO2 pressurization system 20 together to the carbon dioxide electrocatalytic conversion unit 30. In this embodiment, the high-concentration gaseous product after multiple cycles between cathode region e and cathode product treatment system 40 is discharged from the system.

[0053] The inlet of the anode product treatment system 50 is connected to the second outlet of the carbon dioxide electrocatalytic conversion unit 30, and the outlet of the anode product treatment system 50 is connected to the fourth inlet of the carbon dioxide electrocatalytic conversion unit 30. Since the oxygen evolution reaction occurs in the anode region f, the electrolyte is introduced, and the product oxygen is discharged together with the electrolyte through the anode outlet. The electrolyte can be recycled by entering the carbon dioxide electrocatalytic conversion unit 30 through the fourth inlet of the carbon dioxide electrocatalytic conversion unit 30, thereby reducing the consumption of electrolyte.

[0054] It is evident from the above that the carbon dioxide electrocatalytic conversion system provided in this embodiment pressurizes CO2 from the fossil energy utilization system and delivers it to the carbon dioxide electrocatalytic conversion unit. Green electricity is provided by the renewable energy power generation system to conduct the electrocatalytic conversion reaction. Simultaneously, the heat medium circulation system provides heat energy, increasing the temperature and pressure of the electrocatalytic conversion reaction, thereby significantly improving the carbon dioxide processing capacity and conversion rate. The cathode product treatment system enables the recycling of CO2 circulating gas, further improving the CO2 conversion rate. The anode product treatment system enables the recycling of electrolyte, reducing electrolyte consumption.

[0055] See Figure 2In the above embodiments, the carbon dioxide electrocatalytic conversion unit 30 is composed of multiple single cells connected in parallel or series; wherein, each single cell includes: a cathode plate 301, an anode plate 307, and a gas diffusion layer 302, a cathode catalyst layer 303, an anion exchange membrane 304, an anode catalyst layer 305, and a titanium mesh support structure 306 arranged sequentially from the cathode plate 301 to the anode plate 307; wherein, a cathode flow channel region b is provided on the side of the cathode plate 301 near the gas diffusion layer 302, and a cathode thermal medium flow channel region a is formed on the upper surface of the cathode plate 301, the cathode thermal medium flow channel region a is formed by sequentially splicing and laying multiple sets of first vertical pipe assemblies and first horizontal pipe assemblies; the first vertical pipe assembly includes first vertical pipe assemblies arranged in parallel. Vertical pipe 3011 and second vertical pipe 3012 are respectively located near and away from the gas diffusion layer 302; the anode plate 307 has an anode flow channel area d near the titanium mesh support structure 306, and an anode heat medium flow channel area c is formed on the upper surface of the anode plate 307. The anode heat medium flow channel area c is formed by sequentially splicing and laying multiple sets of second vertical pipe assemblies and second horizontal pipe assemblies; the second vertical pipe assembly includes a third vertical pipe 3071 and a fourth vertical pipe 3072 arranged in parallel, and the third vertical pipe 3071 and the fourth vertical pipe 3072 are respectively located near and away from the titanium mesh support structure 306.

[0056] Specifically, the carbon dioxide electrocatalytic conversion unit is in the form of a membrane electrode assembly (MEA) reactor, specifically a multi-cell structure formed by parallel or series connection of single cells consisting of individual MEA assemblies, with multiple single cells arranged to form a battery pack. The single cell structure includes bipolar plates on both sides and a central MEA assembly. The MEA assembly specifically includes a gas diffusion layer 302, a cathode catalyst layer 303, an anion exchange membrane 304, an anode catalyst layer 305, and a titanium mesh support structure 306. Both the cathode plate 301 and the anode plate 307 are bipolar plates, i.e., current collectors. In this embodiment, the cathode plate 301 is a graphite plate, and the anion exchange membrane 304 divides the single cell into a cathode region e and an anode region f.

[0057] The size of the cathode flow channel region b is matched with the size of the membrane electrode and is slightly larger than the size of the membrane electrode. The specific flow channel can adopt various forms such as serpentine, U-shaped, and hybrid.

[0058] The cathode flow channel region b has a gas inlet 3015 and a gas outlet 3016 at both ends, which are used to allow pressurized CO2 to flow in through the gas inlet and undergo a gas-liquid-solid three-phase catalytic reaction on the membrane electrode assembly to obtain reduction products, which are then discharged through the gas outlet.

[0059] The cathode heat medium flow channel area a has a first heat medium inlet 3013 and a first heat medium outlet 3014 at its two ends respectively. The first heat medium inlet 3013 and the gas outlet 3016 are on the same side, and the first heat medium outlet 3014 and the gas inlet 3015 are on the same side, so as to ensure that the flow direction of the heat medium is opposite to the flow direction of the carbon dioxide gas, so as to carry out countercurrent heat exchange.

[0060] The cathode heat medium flow channel region a is a zigzag flow channel formed by sequentially splicing and laying multiple sets of first vertical pipe assemblies and first horizontal pipe assemblies. The heat medium is introduced into the pipe assembly to provide heat to the cathode region e and maintain the required temperature. The first vertical pipe assembly consists of a first vertical pipe 3011 and a second vertical pipe 3012 arranged in parallel. The first vertical pipe 3011 is located on the side of the cathode plate 301 near the gas diffusion layer 302, and the second vertical pipe 3012 is located on the side of the cathode plate 301 away from the gas diffusion layer 302.

[0061] Preferably, the length of the first vertical pipe 3011 is more than three times the length of the second vertical pipe 3012 to ensure that a larger heat exchange area is formed on the membrane electrode side, and the baffle flow pattern formed at the same time utilizes the internal fluid to enhance the turbulence and increase the heat transfer coefficient.

[0062] In a further preferred embodiment, the length of the first vertical pipe 3011 is more than 5 times its diameter to ensure the flow pattern of the heat medium inside it and enhance the heat conduction between it and the membrane electrode.

[0063] The anode plate 307 is a metal plate; graphite plates cannot be used to prevent oxidation and damage to the plate structure. The size of the anode flow channel region d matches the size of the internal anode catalyst layer 305 and the titanium mesh support structure 306, but is slightly larger than the size of the titanium mesh support structure 306. The flow channel can adopt various forms such as serpentine, U-shaped, or hybrid. Electrolyte inlet 3076 and product outlet 3075 are respectively opened at both ends of the anode flow channel region d. Pressurized electrolyte enters through electrolyte inlet 3076 and undergoes a catalytic reaction on the anode catalyst layer 305, yielding oxidation products mainly composed of oxygen, which are then discharged through product outlet 3075.

[0064] The two ends of the anode heat medium flow channel region c are respectively provided with a second heat medium inlet 3073 and a second heat medium outlet 3074. The second heat medium inlet 3073 and the product outlet 3075 are on the same side, and the second heat medium outlet 3074 and the electrolyte inlet 3076 are on the same side, so as to ensure that the flow direction of the heat medium is opposite to that of the electrolyte, so as to carry out countercurrent heat exchange.

[0065] The anode heat medium flow channel region c is a zigzag flow channel formed by sequentially splicing and laying multiple sets of second vertical pipe assemblies and second horizontal pipe assemblies. The heat medium is introduced into the pipe assembly to provide heat to the anode region f and maintain the required temperature. The second vertical pipe assembly consists of a third vertical pipe 3071 and a fourth vertical pipe 3072 arranged in parallel. The third vertical pipe 3071 is located on the side of the anode plate 307 close to the titanium mesh support structure 306, and the fourth vertical pipe 3072 is located on the side of the anode plate 307 away from the titanium mesh support structure 306.

[0066] Preferably, the length of the third vertical pipe 3071 is more than three times the length of the fourth vertical pipe 3072, ensuring that a larger heat exchange area is formed on the internal reaction side, while the baffle flow shape formed utilizes the internal fluid to enhance turbulence and increase the heat transfer coefficient.

[0067] In a further preferred embodiment, the length of the third vertical pipe 3071 is more than 5 times its diameter, ensuring that the heat medium forms a fully developed flow pattern inside it and enhancing heat conduction with the anode catalyst layer 305.

[0068] Since the electrolyte is introduced into the anode region f, more heat is required. Therefore, in this embodiment, the length of the third vertical pipe 3071 is 1 / 4 to 1 / 2 of the length of the first vertical pipe 3011, so as to ensure that the anode heat medium flow channels set on the electrode plate of the anode region f are more dense, which increases the heat exchange area and is conducive to enhancing the heat exchange effect.

[0069] In the above embodiments, the cathode product processing system 40 includes: a cathode product cooler 401, a gas-liquid separator 402, and a cathode product circulation unit 404; wherein, the inlet of the cathode product cooler 401 is connected to the first outlet of the carbon dioxide electrocatalytic conversion unit 30 for cooling the cathode product of the carbon dioxide electrocatalytic conversion unit 30; the inlet of the gas-liquid separator 402 is connected to the outlet of the cathode product cooler 401 for separating the gas phase and liquid phase in the cathode product; the gas phase outlet of the gas-liquid separator 402 is connected to the inlet of the cathode product circulation unit 404 for transporting the gas phase material in the cathode product to the cathode product circulation unit 404; the outlet of the cathode product circulation unit 404 is connected to the first inlet of the carbon dioxide electrocatalytic conversion unit 30 for transporting the cathode product to the cathode region e for recycling.

[0070] Preferably, a dryer 403 is provided between the gas-liquid separator 402 and the cathode product circulation unit 404. The inlet of the dryer 403 is connected to the gas phase outlet of the gas-liquid separator 402, and the outlet of the dryer 403 is connected to the inlet of the cathode product circulation unit 404, so as to dry the gas phase substances in the cathode product and then transport them to the cathode product circulation unit 404.

[0071] In this embodiment, the cathode product cooler 401 is a partition wall heat exchanger. The product in the cathode region e is discharged through the gas outlet and enters the cathode product cooler 401 for cooling. After that, the liquid phase product is separated by the gas-liquid separator 402. The gas phase product is then dried by the dryer 403 to remove the small amount of moisture entrained in the gas and enters the cathode product circulation unit 404. The cathode product circulation unit 404 is mainly a gas compressor. After being pressurized, part of the gas product is mixed again with the CO2 gas pressurized by the CO2 pressurization system 20 in the inlet mixing system 80 and then enters the cathode region e of the electrolytic cell of the carbon dioxide electrocatalytic conversion unit 30. The other gas phase product is discharged from the system through the product circulation unit.

[0072] Furthermore, the cathode product processing system 40 also includes a liquid phase product separation and purification system 405; wherein the inlet of the liquid phase product separation and purification system 405 is connected to the liquid phase outlet of the gas-liquid separator 402, for purifying the liquid phase product separated by the liquid phase separator.

[0073] In the above embodiments, the anode product processing system 50 includes: an anode product cooler 501, an oxygen separator 502, and an electrolyte circulation pressurization pump 504; wherein, the inlet of the anode product cooler 501 is connected to the second outlet of the carbon dioxide electrocatalytic conversion unit 30, for cooling the anode product of the carbon dioxide electrocatalytic conversion unit 30; the inlet of the oxygen separator 502 is connected to the outlet of the anode product cooler 501, for separating oxygen from the anode product and outputting it as a by-product; the inlet of the electrolyte circulation pressurization pump 504 is connected to the outlet of the oxygen separator 502, for pressurizing the electrolyte separated by the oxygen separator 502; the outlet of the electrolyte circulation pressurization pump 504 is connected to the second inlet of the carbon dioxide electrocatalytic conversion unit 30, for transporting the pressurized electrolyte to the anode region f of the carbon dioxide electrocatalytic conversion unit 30 for recycling.

[0074] Preferably, an electrolyte buffer tank 503 is provided between the oxygen separator 502 and the electrolyte circulation pressurization pump 504. One inlet of the electrolyte buffer tank 503 is connected to the outlet of the oxygen separator 502 to store the electrolyte separated by the oxygen separator 502; the outlet of the electrolyte buffer tank 503 is connected to the inlet of the electrolyte circulation pressurization pump 504 to deliver the electrolyte to the electrolyte circulation pressurization pump 504 for pressurization. The electrolyte buffer tank 503 is also provided with an electrolyte replenishment port to replenish a certain amount of fresh electrolyte in a timely manner according to the changes in the concentration and pH value of the returned electrolyte.

[0075] In this embodiment, an oxygen evolution reaction occurs in the anode region f, through which an electrolyte is passed. The product oxygen, along with the electrolyte, is discharged through the product outlet 3075 of the anode region f and enters the anode product cooler 501 for cooling. The gaseous oxygen product is then separated by the oxygen separator 502 and output as a by-product. The liquid electrolyte enters the electrolyte buffer tank 503 for storage. The electrolyte circulation pressurization pump 504 pressurizes the electrolyte delivered from the electrolyte buffer tank 503 to 0.5-2.5 MPa and then delivers it to the anode region f of the carbon dioxide electrocatalytic conversion unit 30.

[0076] Method Implementation Examples:

[0077] This invention also provides a method for electrocatalytic conversion of carbon dioxide, comprising:

[0078] In the carbon dioxide generation and pressurization step, the CO2 pressurization system 20 pressurizes the carbon dioxide generated by the fossil energy utilization system 60 to obtain CO2 at a preset pressure.

[0079] Specifically, the preset pressure is 0.5-3.5 MPa. Industries that use fossil fuels as fuel or raw materials, such as power generation, steel, cement, building materials, and chemicals, will produce carbon dioxide. Depending on the concentration of carbon dioxide in the flue gas, different capture methods are used to capture it, resulting in high-concentration carbon dioxide. The CO2 pressurization system 20 then pressurizes the upstream carbon dioxide.

[0080] In the power generation process, the renewable energy power generation system 70 utilizes renewable energy to generate green electricity.

[0081] Specifically, renewable energy sources, including solar, hydropower, wind, geothermal, and tidal energy, generate green electricity that does not produce carbon emissions. This electricity is converted into direct current by a power conversion system to provide energy for subsequent electrolysis and heating of the heat transfer medium.

[0082] In the heat medium circulation heating step, the heat medium circulation system 10 uses industrial waste heat generated by the fossil energy utilization system 60, superheated steam, or green electricity generated by the renewable energy power generation system 70 to provide heat to the heat medium and heat the heat medium to a preset temperature.

[0083] Specifically, the preset temperature is 70-130℃. Industrial waste heat, superheated steam, or renewable green electricity generated by the fossil energy utilization system 60 are used to provide the required heat for the circulating medium, heating it to 70-130℃. The specific heating temperature is adjusted according to the temperature required for the reaction in the carbon dioxide electrocatalytic conversion unit 30, ensuring that the temperature of the carbon dioxide electrocatalytic conversion reaction unit is maintained within the set range.

[0084] In the carbon dioxide electrocatalytic conversion step, the carbon dioxide electrocatalytic conversion unit 30 performs electrocatalytic conversion on the pressurized CO2, and the cathode product treatment system 40 and the anode product treatment system 50 respectively treat the cathode product and the anode product of the carbon dioxide electrocatalytic conversion unit 30 to realize the recycling of the cathode product and the anode product.

[0085] Specifically, pressurized CO2 from upstream is electrocatalytically converted in a single cell, resulting in the reduction of carbon dioxide. Different catalysts yield different products (CO, ethylene, ethanol, etc.). An oxygen evolution reaction occurs at the anode of the electrolytic cell, and the resulting oxygen product is discharged through the anode outlet along with the electrolyte. The specific reactions are as follows:

[0086] Cathode side: CO2 + H2O + ne – → CO / C2H4 / C2H6O + OH -

[0087] 2H₂O + 2e⁻ → H₂ + 2OH⁻ -

[0088] Anode side: 2OH - → O2 + 2H + + 2e –

[0089] In this embodiment, the temperature of a single cell in the carbon dioxide electrocatalytic conversion unit 30 is 60-120°C; the reaction pressure of the cathode region e of the single cell is 0.5-3 MPa, the reaction pressure of the anode region f is 0.1-2 MPa, and the pressure difference between the cathode region e and the anode region f is 0.4-1 MPa.

[0090] Increasing the temperature is beneficial for improving the reaction rate; the temperature of the electrolytic cell should be controlled at 60-120℃. Simultaneously, increasing the temperature significantly improves the performance of the anion exchange membrane 304, increasing the hydroxide ion conduction rate. However, the increased temperature also increases the hydrogen evolution side reaction on the cathode side, leading to an increase in the hydrogen content in the product. To reduce the hydrogen content in the product and increase the single-pass conversion rate of carbon dioxide, it is necessary to increase the carbon dioxide pressure on the cathode side, thereby increasing the carbon dioxide concentration and promoting the carbon dioxide electrolytic reduction reaction. The cathode side reaction pressure should be maintained at 0.5-3 MPa, and the anode side pressure at 0.1-2 MPa, with the pressure difference controlled at 0.4-1 MPa. This prevents excessive water from entering the cathode side through the anion exchange membrane 304, which could damage the membrane electrode structure, cause flooding, and affect the diffusion of carbon dioxide and the reduction reaction.

[0091] The product from cathode region e is discharged through the gas outlet and enters the cathode product cooler 401 for cooling. Afterwards, the liquid phase product is separated by the gas-liquid separator 402. The gas phase is then dried by the dryer 403 to remove any entrained moisture before entering the product circulation unit. After pressurization, the product is mixed again with the pressurized CO2 gas at the inlet in the inlet mixing system 80 and then enters the cathode side of the electrolytic cell for recycling, improving the total carbon dioxide conversion rate. In anode region f, an oxygen evolution reaction occurs, and electrolyte is introduced. The product oxygen, along with the electrolyte, is discharged through the product outlet 3075 of anode region f. After cooling by the anode product cooler 501, it enters the oxygen separator 502 to separate the gaseous oxygen product as a byproduct. The liquid electrolyte enters the electrolyte buffer tank 503, which is equipped with a fresh electrolyte replenishment port. Based on the returned electrolyte concentration and pH changes, a certain amount of fresh electrolyte is replenished in a timely manner to control the solution concentration in the electrolyte buffer tank 503 within the required range. The liquid in the electrolyte buffer tank 503 is pressurized to 0.5-2.5 MPa by the electrolyte circulation pump and then transported to the anode area f of the carbon dioxide electrocatalytic conversion unit 30 for recycling.

[0092] The relevant parts of the method embodiments and the system embodiments described above can be referred to each other, and will not be repeated here.

[0093] The carbon dioxide electrocatalytic conversion method provided by this invention pressurizes the upstream carbon dioxide and delivers it to the carbon dioxide electrocatalytic conversion unit. By controlling the temperature of the carbon dioxide electrocatalytic reaction, the performance of the ion exchange membrane is improved, the rate of carbon dioxide electrocatalytic reduction reaction is increased, the single-pass conversion rate of carbon dioxide is improved, the cell pressure of the electrolysis system is reduced, and the power consumption is reduced, thus greatly increasing the efficiency of the carbon dioxide electrocatalytic conversion system.

[0094] In summary, the carbon dioxide electrocatalytic conversion method provided by this invention significantly improves the carbon dioxide processing capacity and conversion rate per cell by increasing the temperature and pressure of the electrolysis reaction, while also increasing the reaction rate and reducing the cell pressure. The energy conversion efficiency is more than 30% higher than that of the prior art.

[0095] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A carbon dioxide electrocatalytic conversion system, characterized in that, include: The system includes a heat transfer medium circulation system, a CO2 pressurization system, a carbon dioxide electrocatalytic conversion unit, a cathode product treatment system, and an anode product treatment system; among which, The inlet of the CO2 pressurization system is connected to the first outlet of the fossil energy utilization system, in order to pressurize the CO2 generated by the fossil energy utilization system. The first inlet, second inlet, and third inlet of the carbon dioxide electrocatalytic conversion unit are respectively connected to the outlet of the CO2 pressurization system, the first green electricity outlet of the renewable energy power generation system, and the first outlet of the heat medium circulation system, so as to utilize the pressurized carbon dioxide, the electrical energy generated by the renewable energy power generation system, and the heat energy generated by the heat medium circulation system to carry out the electrocatalytic conversion reaction of carbon dioxide. The inlet of the cathode product treatment system is connected to the first outlet of the carbon dioxide electrocatalytic conversion unit to treat the cathode products of the carbon dioxide electrocatalytic conversion unit; the first inlet of the carbon dioxide electrocatalytic conversion unit is connected to the CO2 circulating gas outlet of the cathode product treatment system to recycle the CO2 circulating gas and improve the carbon dioxide conversion rate. The inlet of the anode product treatment system is connected to the second outlet of the carbon dioxide electrocatalytic conversion unit for treating the anode products of the carbon dioxide electrocatalytic conversion unit; the fourth inlet of the carbon dioxide electrocatalytic conversion unit is connected to the electrolyte outlet of the anode product treatment system for recycling the electrolyte. The carbon dioxide electrocatalytic conversion unit is composed of multiple single cells connected in parallel or series; wherein, each single cell includes: a cathode plate, an anode plate, and a gas diffusion layer, a cathode catalyst layer, an anion exchange membrane, an anode catalyst layer, and a titanium mesh support structure arranged sequentially from the cathode plate to the anode plate; the gas diffusion layer, cathode catalyst layer, anion exchange membrane, anode catalyst layer, and titanium mesh support structure constitute a membrane electrode assembly; wherein, A cathode flow channel region is provided on the side of the cathode plate near the gas diffusion layer, and a cathode heat medium flow channel region is formed on the upper surface of the cathode plate. The cathode heat medium flow channel region is formed by sequentially splicing and laying multiple sets of first vertical pipe assemblies and first horizontal pipe assemblies; the first vertical pipe assembly includes a first vertical pipe and a second vertical pipe arranged in parallel. The first vertical pipe and the second vertical pipe are respectively located near and away from the gas diffusion layer; the two ends of the cathode heat medium flow channel area are respectively provided with a first heat medium inlet and a first heat medium outlet; An anode flow channel area is provided on the side of the anode plate near the titanium mesh support structure. An anode heat medium flow channel area is formed on the upper surface of the anode plate. The anode heat medium flow channel area is formed by sequentially splicing and laying multiple sets of second vertical pipe assemblies and second horizontal pipe assemblies. The second vertical pipe assembly includes a third vertical pipe and a fourth vertical pipe arranged in parallel. The third vertical pipe and the fourth vertical pipe are respectively located near and away from the titanium mesh support structure. A second heat medium inlet and a second heat medium outlet are respectively formed at both ends of the anode heat medium flow channel area.

2. The carbon dioxide electrocatalytic conversion system according to claim 1, characterized in that, The cathode flow channel region has a gas inlet and a gas outlet at each end, respectively, to allow pressurized CO2 to flow in through the gas inlet and undergo a gas-liquid-solid three-phase catalytic reaction on the membrane electrode assembly, yielding reduction products, which are then discharged through the gas outlet. The gas outlet is located on the same side as the first heat medium inlet, and the gas inlet is located on the same side as the first heat medium outlet, to ensure that the flow direction of the heat medium is opposite to the flow direction of the carbon dioxide gas, thus achieving countercurrent heat exchange; and / or The anode flow channel region has an electrolyte inlet and a product outlet at each end, respectively, so that pressurized electrolyte enters through the electrolyte inlet and undergoes a catalytic reaction on the anode catalyst layer to obtain an oxidation product mainly composed of oxygen, which is discharged through the product outlet. The product outlet and the second heat medium inlet are on the same side, and the electrolyte inlet and the second heat medium outlet are on the same side, so as to ensure that the flow direction of the heat medium is opposite to that of the electrolyte, so as to perform countercurrent heat exchange.

3. The carbon dioxide electrocatalytic conversion system according to claim 1, characterized in that, The dimensions of the cathode flow channel region are matched to the dimensions of the membrane electrode assembly; the flow channel of the cathode flow channel region is serpentine, U-shaped, or a hybrid type; and / or The dimensions of the anode flow channel region are matched with the dimensions of the anode catalyst layer and the titanium mesh support structure; the flow channels of the anode flow channel region are serpentine, U-shaped, or a hybrid type.

4. The carbon dioxide electrocatalytic conversion system according to claim 1, characterized in that, The cathode plate is a graphite plate; and / or the anode plate is a metal plate.

5. The carbon dioxide electrocatalytic conversion system according to claim 1, characterized in that, The length of the first vertical pipe is more than three times the length of the second vertical pipe; and / or The length of the third vertical pipe is more than three times the length of the fourth vertical pipe; and / or The length of the third vertical pipe is 1 / 4 to 1 / 2 of the length of the first vertical pipe.

6. The carbon dioxide electrocatalytic conversion system according to claim 1, characterized in that, The length of the first vertical pipe is more than 5 times its diameter; and / or the length of the third vertical pipe is more than 5 times its diameter.

7. The carbon dioxide electrocatalytic conversion system according to claim 1, characterized in that, The cathode product processing system includes: a cathode product cooler, a gas-liquid separator, and a cathode product circulation unit; wherein... The inlet of the cathode product cooler is connected to the first outlet of the carbon dioxide electrocatalytic conversion unit to cool the cathode product of the carbon dioxide electrocatalytic conversion unit; the inlet of the gas-liquid separator is connected to the outlet of the cathode product cooler to separate the gas phase and liquid phase in the cathode product. The gas phase outlet of the gas-liquid separator is connected to the inlet of the cathode product circulation unit to transport the gas phase substances in the cathode product to the cathode product circulation unit. The outlet of the cathode product recycling unit is connected to the first inlet of the carbon dioxide electrocatalytic conversion unit to transport the cathode product to the cathode area for recycling.

8. The carbon dioxide electrocatalytic conversion system according to claim 1, characterized in that, The anode product processing system includes: an anode product cooler, an oxygen separator, and an electrolyte circulation and pressurization pump; wherein... The inlet of the anode product cooler is connected to the second outlet of the carbon dioxide electrocatalytic conversion unit to cool the anode product of the carbon dioxide electrocatalytic conversion unit; the inlet of the oxygen separator is connected to the outlet of the anode product cooler to separate the oxygen from the anode product and output it as a by-product. The inlet of the electrolyte circulation pressurization pump is connected to the outlet of the oxygen separator to pressurize the electrolyte separated by the oxygen separator; the outlet of the electrolyte circulation pressurization pump is connected to the second inlet of the carbon dioxide electrocatalytic conversion unit to transport the pressurized electrolyte to the anode area of ​​the carbon dioxide electrocatalytic conversion unit for recycling.

9. The carbon dioxide electrocatalytic conversion system according to claim 1, characterized in that, Also includes: Intake mixing system; among which, The first and second inlets of the air intake mixing system are respectively connected to the outlet of the CO2 pressurization system and the outlet of the cathode product treatment system. The outlet of the air intake mixing system is connected to the first inlet of the carbon dioxide electrocatalytic conversion unit, so as to mix the pressurized CO2 and the circulating gas generated by the carbon dioxide electrocatalytic conversion unit and then transport them to the carbon dioxide electrocatalytic conversion unit.

10. A method for electrocatalytic conversion of carbon dioxide using the carbon dioxide electrocatalytic conversion system as described in claim 1, characterized in that, include: The CO2 pressurization system pressurizes the carbon dioxide produced by the fossil energy utilization system to obtain CO2 at a preset pressure; Renewable energy power generation systems use renewable energy to generate green electricity; The heat medium circulation system uses industrial waste heat or superheated steam generated by the fossil energy utilization system or green electricity generated by the renewable energy power generation system to provide heat to the heat medium and heat the heat medium to a preset temperature; The carbon dioxide electrocatalytic conversion unit performs electrocatalytic conversion on the pressurized CO2. The cathode product treatment system and the anode product treatment system respectively process the cathode product and the anode product of the carbon dioxide electrocatalytic conversion unit to achieve the recycling of the cathode product and the anode product. In this process, the flow direction of the heat medium is ensured to be opposite to the flow direction of the carbon dioxide gas to achieve countercurrent heat exchange; or the flow direction of the heat medium is ensured to be opposite to the flow direction of the electrolyte to achieve countercurrent heat exchange.

11. The method for electrocatalytic conversion of carbon dioxide according to claim 10, characterized in that, The preset pressure is 0.5-3.5 MPa; the preset temperature is 70-130°C.

12. The method for electrocatalytic conversion of carbon dioxide according to claim 10, characterized in that, The electrochemical reactions occurring in the carbon dioxide electrocatalytic conversion unit are as follows: Cathode side: CO2 + H2O + ne - →CO / C2H4 / C2H6O+OH - 2H2O+2e - →H2 + 2OH - Anode side: 2OH - →O2+2H + +2e – .

13. The method for electrocatalytic conversion of carbon dioxide according to claim 10, characterized in that, The temperature of a single cell in the carbon dioxide electrocatalytic conversion unit is 60-120℃; the reaction pressure in the cathode region of the single cell is 0.5-3MPa, the reaction pressure in the anode region is 0.1-2MPa, and the pressure difference between the cathode region and the anode region is 0.4-1MPa.

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