High-temperature electrochemical hydrogen purification and compression device

Abstract

The invention discloses a high-temperature electrochemical hydrogen purification and compression device, and belongs to the field of hydrogen production equipment. The hydrogen purification and compression device comprises end plates on the two sides, a plurality of middle end plates are arranged between the two end plates, and membrane electrodes are arranged between the end plates and the middle end plates and between every two adjacent middle end plates; and etching flow fields are formed on the end plates and the middle end plate. The electrochemical hydrogen purification and compression device has good purification and compression effects on hydrogen mixed gas containing carbon monoxide. Test is carried out under the gas inlet conditions that the temperature is 150 DEG C, the gas inlet composition comprises hydrogen and carbon monoxide, the volume ratios of the hydrogen and the carbon monoxide are 95% and 5% respectively, and the pressure is normal pressure, the purity of the hydrogen reaches 99.99%, and the pressure is 31 MPa.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen production equipment, and in particular to a high-temperature electrochemical hydrogen purification and compression device for preparing high-purity and high-pressure hydrogen. Background Art

[0002] The hydrogen energy industry chain is long and the technology is complex, involving production, storage, transportation and use. Traditional hydrogen separation and purification technologies mainly include: pressure swing adsorption (PSA), cryogenic separation, metal hydride purification and membrane separation, but hydrogen compression and purification methods have problems of high energy consumption and high cost. Therefore, the development of high-efficiency, low-cost, reliable performance and large-scale hydrogen separation, purification and compression technology will be the key link.

[0003] Electrochemical purification and compression of hydrogen technology provides a new option for hydrogen storage and transportation. Electrochemical hydrogen purification and compression technology is based on electrochemical principles and can simultaneously purify and compress hydrogen. Compared with traditional mechanical compression technology, electrochemical purification and compression of hydrogen technology has the following obvious advantages: using an external electric field to simultaneously purify and compress hydrogen, with high separation efficiency and compression efficiency; no moving parts, no noise, no lubricating oil pollution of high-pressure hydrogen products; the device has a compact structure and is easy to scale up. The theoretical compression ratio is infinite, and it has high compression efficiency at a high compression ratio. In addition to realizing the low-energy hydrogen compression function, the catalytic selectivity of the electrode and the separation selectivity of the proton exchange membrane can also simultaneously purify hydrogen and directly prepare high-pressure hydrogen with a purity of >99%. Electrochemical purification and compression of hydrogen technology is considered to be a more effective and commercially promising method of compressing hydrogen. The operating temperature of the currently commonly used electrochemical purification and compression hydrogen technology is usually room temperature. However, the current upstream hydrogen often contains carbon monoxide impurity gas. The toxic effect of low-temperature carbon monoxide on the system cannot be ignored. Therefore, it is of great significance to develop a high-temperature electrochemical purification and compression hydrogen device to reduce the impact of carbon monoxide on system performance. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a high-temperature electrochemical hydrogen purification and compression device.

[0005] The present invention is achieved by adopting the following technical solutions.

[0006] A high-temperature electrochemical hydrogen purification and compression device comprises end plates on both sides, a plurality of intermediate end plates are arranged between the two end plates, membrane electrodes are arranged between the end plates and the intermediate end plates and between two adjacent intermediate end plates; an etched flow field is formed on the end plates and the intermediate end plates.

[0007] Furthermore, sealing gaskets and insulating gaskets are provided between the end plate and the middle end plate and between two adjacent middle end plates.

[0008] Furthermore, the insulating gasket is made of a material including polytetrafluoroethylene, and the thickness of the insulating gasket is 2 to 20 μm.

[0009] Furthermore, the sealing gasket is an O-ring, which is embedded in the sealing grooves on the end plate and the middle end plate, and the sealing grooves are arranged outside the etching flow field of the end plate and the middle end plate.

[0010] Furthermore, the end plate is also provided with a gas transmission hole and a liquid transmission hole.

[0011] Furthermore, the liquid transmitted by the liquid transmission hole selects the corresponding liquid type according to the required control temperature range; water is selected as the liquid medium below 90°C, and alkylbenzene heat transfer oil is selected as the liquid medium above 90°C and below 300°C.

[0012] Furthermore, the end plate is connected with a conductive sheet, and the material of the conductive sheet includes gold, platinum, titanium, and gold-plated metal.

[0013] Furthermore, the membrane electrode comprises a proton exchange membrane, a catalyst layer is arranged on both sides of the proton exchange membrane, a gas diffusion layer is arranged outside the catalyst layer, and a metal plate is arranged outside the gas diffusion layer; the membrane electrode has a thickness of 50 to 200 μm.

[0014] Furthermore, the materials used for the proton exchange membrane include sulfonated hydrocarbons, acid-doped alkaline polymers, preferably sulfonated polyetheretherketone, sulfonated polysulfone, and sulfonated polyimide; the catalyst layer is Pd / C; the materials used for the gas diffusion layer include porous carbon cloth, carbon felt, and carbon paper.

[0015] Furthermore, the metal plate is provided with a plurality of holes, and the hole diameter is 20-200 meshes; the material selected for the metal plate includes titanium alloy and stainless steel.

[0016] This application has the following beneficial effects.

[0017] The electrochemical hydrogen purification and compression device of the present invention has good purification and compression effects on hydrogen mixed gas containing carbon monoxide. Under the conditions of 150°C, the intake gas composition is hydrogen and carbon monoxide, the volume ratio is 95% and 5% respectively, and the pressure is normal pressure, the hydrogen purity reaches 99.99% and the pressure is 31MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the present invention;

[0019] Figure 2 is a front view of the end plate of the present invention;

[0020] Figure 3 is a top view of the end plate of the present invention;

[0021] Figure 4 It is a schematic diagram intended to embody the structure of the second etching flow field and the second sealing slot on the middle end plate of the present invention.

[0022] Among them, 1. end plate; 2. sealing gasket; 3. membrane electrode; 4. insulating gasket; 5. middle end plate; 6. etching flow field one; 7. sealing slot one; 8. conductive sheet; 9. gas transmission hole; 10. liquid transmission hole; 11. etching flow field two; 12. sealing slot two. DETAILED DESCRIPTION

[0023] The present patent application is further described below in conjunction with embodiments.

[0024] like Figure 1-4 As shown, a high-temperature electrochemical hydrogen purification and compression device includes four parts: an end plate 1 with a heating oil bath, a gasket, a membrane electrode 3, and an intermediate end plate 5.

[0025] Specifically, two end plates 1 are provided, which are located on both sides of the entire device. The end plate 1 is composed of two metal plates, and an etching flow field 6 is formed in the center of the metal plate located on the inner side, and an annular sealing groove 7 is provided around the etching flow field 6. The end plate 1 also forms a gas transmission hole 9 and a liquid transmission hole 10. The gas transmission hole 9 is used for mixed gases such as hydrogen, nitrogen, and carbon monoxide to enter the system or pure hydrogen to be discharged from the system; the liquid transmission hole 10 is used for liquid medium to enter and discharge the system. The type of corresponding liquid medium is selected according to the required control temperature range. Water is preferably used as the liquid medium below 90°C, and alkylbenzene heat transfer oil is preferably used as the liquid medium above 90°C and below 300°C. The present application also connects a conductive sheet 8 to the end plate 1. The conductive sheet 8 is preferably made of gold, platinum, titanium, and other metals with gold-plated surfaces.

[0026] The intermediate end plate 5 is provided with several pieces and is placed between the two end plates 1. The intermediate end plate 5 is composed of two metal plates, and the centers of the two metal plates form an etching flow field 2 11, and an annular sealing groove 2 12 is provided around the etching flow field 2 11. The intermediate end plate 5 is also connected to a conductive sheet 8.

[0027] The membrane electrode 3 is provided in several pieces and is installed between the end plate 1 and the middle end plate 5 and between two adjacent middle end plates 5. The membrane electrode 3 is composed of a proton exchange membrane, a catalyst layer, a gas diffusion layer, and a metal plate. Specifically, the catalyst layer is covered on both sides of the proton exchange membrane, the gas diffusion layer is covered on the outside of the catalyst layer, and the metal plate is covered on the outside of the gas diffusion layer, so as to prepare the membrane electrode 3. The proton exchange membrane of the present application can be a sulfonated hydrocarbon type, an acid-doped alkaline polymer type; the gas diffusion layer is preferably a porous carbon cloth, a carbon felt, a carbon paper, etc. The metal plate is a porous titanium alloy, a porous stainless steel, etc., and the pore size is preferably 20-200 mesh.

[0028] In order to ensure the sealing of the entire device, the present application provides gaskets between the end plate 1 and the intermediate end plate 5 and between two adjacent intermediate end plates 5, and the gaskets include two types: sealing gasket 2 and insulating gasket 4. The sealing gasket 2 is an O-ring, which is embedded in the sealing card groove 1 7 and the sealing card groove 2 12. The insulating gasket 4 is made of polytetrafluoroethylene (PTFE) and the like. According to the material and thickness of the membrane electrode 3, the thickness of the insulating gasket 4 can be preferably 2 to 20 μm.

[0029] The hydrogen purification and compression device used in the following embodiments of the present application is as follows: Figure 1 As shown, it includes two end plates 1, between which two middle end plates 5, three membrane electrodes 3, three insulating gaskets 4 and several sealing gaskets 2 are arranged, and the above components are connected by bolts. The working principle is as follows: a mixed gas such as hydrogen, nitrogen, and carbon monoxide enters the system through an end plate 1 on one side. Driven by the electric field, the low-pressure raw gas on the inlet side of the end plate generates protons through a hydrogen oxidation reaction. The protons pass through the proton exchange membrane electrode and transfer to the other side end plate 1, and then are reduced to high-pressure product gas through a hydrogen evolution reaction, while the impurity gas cannot pass through the proton exchange membrane, and the reduced hydrogen is enriched on the sealed cathode side.

[0030] Example 1

[0031] Titanium alloy is used as the end plate and the middle end plate, the liquid medium is alkylbenzene heat transfer oil, and the phosphoric acid-doped polybenzimidazole membrane electrode is assembled into a high-temperature electrochemical purification and hydrogen compression device. The membrane electrode thickness is 50 μm, and the insulating gasket is a PTFE gasket with a thickness of 5 μm.

[0032] The performance of the membrane electrode was tested using an electrochemical hydrogen purification and compression device at a temperature of 150°C. The intake gas composition was hydrogen, nitrogen, and carbon monoxide, with volume ratios of 70%, 20%, and 10%, respectively. The pressure was normal pressure. After purification and compression, the hydrogen purity reached 99.88% and the pressure was 25MPa.

[0033] Example 2

[0034] Titanium alloy is used as the end plate and the middle end plate, the liquid medium is water, and the sulfonated polyetheretherketone membrane electrode is assembled into a high-temperature electrochemical purification and hydrogen compression device. The membrane electrode thickness is 80 μm, and the insulating gasket is a PTFE gasket with a thickness of 7 μm.

[0035] The performance of the membrane electrode was tested using an electrochemical hydrogen purification and compression device at a temperature of 80°C. The intake gas composition was hydrogen and carbon monoxide, with volume ratios of 95% and 5% respectively. The pressure was normal pressure. After purification and compression, the hydrogen purity reached 99.79% and the pressure was 30MPa.

[0036] Example 3

[0037] Gold-plated stainless steel is used as the end plate and the middle end plate, the liquid medium is alkylbenzene heat transfer oil, and the phosphoric acid-doped polybenzimidazole membrane electrode is assembled into a high-temperature electrochemical purification and hydrogen compression device. The membrane electrode thickness is 100 μm, and the insulating gasket is a PTFE gasket with a thickness of 10 μm.

[0038] The performance of the membrane electrode was tested using an electrochemical hydrogen purification and compression device at a temperature of 150°C. The intake gas composition was hydrogen and carbon monoxide, with volume ratios of 95% and 5% respectively. The pressure was normal pressure. After purification and compression, the hydrogen purity reached 99.99% and the pressure was 31MPa.

[0039] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-temperature electrochemical hydrogen purification and compression device, characterized in that: It comprises end plates (1) on both sides, a plurality of intermediate end plates (5) are arranged between the two end plates (1), and membrane electrodes (3) are arranged between the end plates (1) and the intermediate end plates (5) and between two adjacent intermediate end plates (5); an etched flow field is formed on both the end plates (1) and the intermediate end plates (5).

2. A high temperature electrochemical hydrogen purification and compression device according to claim 1, characterized in that: A sealing gasket (2) and an insulating gasket (4) are also provided between the end plate (1) and the middle end plate (5) and between two adjacent middle end plates (5).

3. A high temperature electrochemical hydrogen purification and compression device according to claim 2, characterized in that: The insulating gasket (4) is made of a material including polytetrafluoroethylene, and the thickness of the insulating gasket (4) is 2 to 20 μm.

4. A high temperature electrochemical hydrogen purification and compression device according to claim 2, characterized in that: The sealing gasket (2) is an O-ring, and the sealing gasket (2) is embedded in the sealing grooves on the end plate (1) and the middle end plate (5), and the sealing grooves are arranged outside the etching flow field of the end plate (1) and the middle end plate (5).

5. A high temperature electrochemical hydrogen purification and compression device according to claim 1, characterized in that: The end plate (1) is also provided with a gas transmission hole (9) and a liquid transmission hole (10).

6. A high temperature electrochemical hydrogen purification and compression device according to claim 5, characterized in that: The liquid transmitted by the liquid transmission hole (10) is selected according to the required control temperature range. Water is selected as the liquid medium below 90°C, and alkylbenzene heat transfer oil is selected as the liquid medium above 90°C and below 300°C.

7. A high temperature electrochemical hydrogen purification and compression device according to claim 1, characterized in that: The end plate (1) is connected to a conductive sheet (8), and the conductive sheet (8) is made of a material including gold, platinum, titanium, and a metal with a gold-plated surface.

8. A high temperature electrochemical hydrogen purification and compression device according to claim 1, characterized in that: The membrane electrode (3) comprises a proton exchange membrane, catalyst layers are arranged on both sides of the proton exchange membrane, a gas diffusion layer is arranged outside the catalyst layer, and a metal plate is arranged outside the gas diffusion layer; the membrane electrode (3) has a thickness of 50 to 200 μm.

9. A high temperature electrochemical hydrogen purification and compression device according to claim 8, characterized in that: The materials selected for the proton exchange membrane include sulfonated hydrocarbons and acid-doped alkaline polymers; the catalyst layer is Pd / C; and the materials selected for the gas diffusion layer include porous carbon cloth, carbon felt, and carbon paper.

10. A high temperature electrochemical hydrogen purification and compression device according to claim 8, characterized in that: The metal plate is provided with a plurality of holes, and the hole diameter is 20-200 meshes; the material selected for the metal plate includes titanium alloy and stainless steel.

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