An electrochemical hydrogen pump for preparing high-pressure hydrogen

Abstract

The present invention relates to a multi-stage electrochemical hydrogen pump for preparing high-pressure hydrogen, wherein the multi-stage electrochemical hydrogen pump for preparing high-pressure hydrogen is composed of a fastening end plate and a fastening screw, an insulating plate, an electrode plate, a partitioning fixed plate, a gas-liquid transmission plate, a membrane electrode assembly, and the like. The partitioning fixed plate and the gas-liquid transmission plate form an air chamber assembly, and the inner hole space thereof is directly used as an air chamber, which reduces the dead volume and increases the safety; increases the contact area with the membrane electrode, provides the best support for the membrane electrode, and reduces the ohmic impedance at the same time, thereby improving the efficiency of the hydrogen pump; the multi-stage electrochemical hydrogen pump is composed of a plurality of hydrogen pumps connected in series to achieve step-by-step pressurization. The structure is simple, easy to process and manufacture, suitable for large-scale production, can greatly reduce costs, and at the same time make the assembly process and requirements relatively simple and easy to control. The technology has a wide range of applications, ranging from portable mobile hydrogen boosting equipment to fixed hydrogen refueling stations, and can also be used for high-purity hydrogen purification equipment.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogen production equipment, and in particular to an electrochemical hydrogen pump for preparing high-pressure hydrogen. Background Art

[0002] At present, making full use of natural energy and hydrogen energy is the best choice to achieve carbon emission reduction and cope with the depletion of fossil energy. The use of hydrogen energy requires solving key issues in the production, storage, transportation and utilization of hydrogen.

[0003] Hydrogen mostly exists in gaseous state. During storage and transportation, hydrogen must be compressed into high-pressure hydrogen or liquefied into liquid hydrogen. The method of compressing hydrogen into high-pressure hydrogen is mainly to compress hydrogen by repeatedly doing work with mechanical energy, and then store it in high-pressure gas cylinders. Not only is the boosting equipment huge, the working process consumes a lot of energy and is noisy, and the reciprocating movement of the booster pump will also cause seal wear and leakage. More importantly, when hydrogen is compressed to a certain high pressure, the compression factor increases, making it difficult to compress further, and it consumes more energy.

[0004] At present, electrochemical hydrogen pumps can be used to replace the commonly used reciprocating mechanical superchargers. Compared with the latter, electrochemical hydrogen pumps have many advantages, such as compactness, high boosting efficiency, no maintenance due to the lack of mechanical moving parts, and almost no noise. Electrochemical hydrogen pumps are basically composed of two gas chambers separated by a proton conduction membrane. Electrochemical catalysts are provided on both sides of the proton conduction membrane. When an external direct current is connected, the low-pressure hydrogen in the positive gas chamber dissociates into protons under the action of electrocatalysis and is transferred to the negative gas chamber through the proton conduction membrane to regenerate high-pressure hydrogen, as shown in formula (1).

[0005] E=(RT / 2F)ln(P2 / P2)+ir (1)

[0006] In formula (1), E is the DC voltage applied to both sides of the hydrogen pump (V), R is the gas constant (8.3145 J / K·mol), T is the temperature inside the hydrogen pump (K), F is the Faraday constant (96485 C / mol), P1 represents the pressure on the positive electrode side (Pa), P2 represents the pressure on the negative electrode side (Pa), i represents the current (A), and r represents the total battery resistance (Ω).

[0007] When the temperature, current and total resistance remain unchanged, the greater the DC voltage applied, the greater the multiple of the increase in hydrogen pressure. This multiple increase tends to the power of the natural constant of the voltage value, and the pressurization effect increases dramatically.

[0008] Panasonic Corporation of Japan has done some work on electrochemical hydrogen pumps. In Chinese Patent 110552014A, it mainly describes the strong support structure of the membrane in single-stage pressurization. In Chinese Patent 111082091A, it mainly describes the multi-unit hydrogen pump structure. In Japanese Patents 666751B1, 6719054B2, 6719075B1, 2020117782A, etc., the multi-unit hydrogen pump structures described all adopt the applied voltage as a series mode, and the low-pressure hydrogen entering each unit hydrogen pump is in a parallel mode connected together (the same common pipeline, the same gas pressure), and the high-pressure hydrogen coming out of multiple groups of hydrogen pumps is also in a parallel mode connected together (the same common pipeline, the same gas pressure). Such a structure can only increase the generation of high-pressure hydrogen, and does not increase the hydrogen pressure several times. Summary of the invention

[0009] Based on this, it is necessary to provide an electrochemical hydrogen pump for preparing high-pressure hydrogen to address the problems of high energy consumption, high noise and low efficiency in the pressurization process of current hydrogen production equipment.

[0010] The above purpose is achieved through the following technical solutions:

[0011] An electrochemical hydrogen pump for preparing high-pressure hydrogen comprises a fixed end plate, an insulating plate, an electrode plate, a partitioning fixed plate, a gas-liquid transmission plate and a membrane electrode assembly which are fixedly connected as one body, wherein the gas-liquid transmission plate is fixedly connected to the partitioning fixed plate to form a gas chamber assembly; the fixed end plate, the insulating plate and the electrode plate are each two in number and are arranged opposite to each other, and are sequentially arranged from the outside to the inside in the order of the fixed end plate, the insulating plate and the electrode plate; the gas chamber assemblies are multiple in number, and are arranged between two of the electrode plates, and one membrane electrode assembly is arranged between any two adjacent gas chamber assemblies.

[0012] In one of the embodiments, the partition fixing plate and the gas-liquid transmission plate have the same thickness, the partition fixing plate is provided with a mounting step, the gas-liquid transmission plate is provided with a mounting boss, and the mounting boss is snapped onto the mounting step to fix the gas-liquid transmission plate to the partition fixing plate.

[0013] In one of the embodiments, a groove is provided on one side or both sides of the partition fixing plate, the thickness of the gas-liquid transmission plate is equal to the depth of the groove, the gas-liquid transmission plate is embedded in the groove and fixedly connected to the partition fixing plate; a through hole is provided on the partition fixing plate, and the through hole is opened on the bottom surface of the groove.

[0014] In one of the embodiments, the through holes on the partition fixing plates of two adjacent air chamber assemblies are staggered.

[0015] In one embodiment, the electrode plate includes a positive electrode plate and a negative electrode plate, a low-pressure hydrogen inlet and a low-pressure hydrogen outlet are provided on the fixed end plate close to the positive electrode plate, and a high-pressure hydrogen outlet is provided on the fixed end plate close to the negative electrode plate.

[0016] In one embodiment, the gas-liquid transmission plate is a porous conductive metal plate or a porous conductive carbon plate.

[0017] In one embodiment, the membrane electrode assembly includes a proton conducting membrane, a catalyst layer and a diffusion layer arranged in sequence from inside to outside.

[0018] In one of the embodiments, carbon paper, carbon felt or other common porous conductive materials are provided between the membrane electrode assembly and the gas-liquid transmission plate.

[0019] The beneficial effects of the present invention are:

[0020] 1. The multi-stage electrochemical hydrogen pump for preparing high-pressure hydrogen has many advantages, such as compactness, high boosting efficiency, no maintenance and almost no noise due to the lack of mechanical moving parts;

[0021] 2. The porous gas-liquid transmission plate is used, and its inner pore space is directly used as the gas chamber, which reduces the gas space of the multi-stage electrochemical hydrogen pump, reduces the dead volume, increases the safety, and reduces the volume of the multi-stage hydrogen pump; at the same time, the contact area with the membrane electrode is increased, providing the best support for the membrane electrode, while increasing and reducing the ohmic impedance and improving the efficiency of the hydrogen pump;

[0022] 3. The separation fixing plate and the gas-liquid transmission plate are processed into corresponding convex and concave shapes to form an assembly, so that they can jointly bear the pressure difference on both sides of the membrane electrode, effectively support the membrane electrode, prevent it from deformation, and extend the stability and life of the membrane electrode and hydrogen pump;

[0023] 4. Multiple hydrogen pumps are connected in series to form a multi-stage electrochemical hydrogen pump. Electronic conduction and ion conduction are connected in series in sequence, and from the low-pressure gas chamber to the high-pressure gas chamber, they are connected in series in sequence to improve the boosting effect and reduce energy consumption.

[0024] 5. The structure is simple, easy to process and manufacture, suitable for large-scale production, which can greatly reduce costs, and at the same time make the assembly process and requirements relatively simple and easy to control. It can be used in portable mobile hydrogen boosting equipment and fixed hydrogen refueling stations, and can also be used in high-purity hydrogen preparation equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the structure of a gas chamber component in an electrochemical hydrogen pump for preparing high-pressure hydrogen provided by an embodiment of the present invention;

[0026] Figure 2 for Figure 1A schematic diagram of the structure of an electrochemical hydrogen pump for preparing high-pressure hydrogen provided in an embodiment;

[0027] Figure 3 A schematic structural diagram of a gas chamber assembly in an electrochemical hydrogen pump for preparing high-pressure hydrogen provided by another embodiment of the present invention;

[0028] Figure 4 for Figure 3 The embodiment provides a schematic diagram of the structure of an electrochemical hydrogen pump for preparing high-pressure hydrogen.

[0029] in:

[0030] Fastening end plate 1; screw 2; insulating pad 3; positive plate 4; negative plate 5; partition fixing plate 6; partition fixing plate original plate 6a; gas-liquid transmission plate 7; gas chamber assembly 6-7; membrane electrode assembly 8; through hole 9; through hole 10; low-pressure hydrogen inlet 11, low-pressure hydrogen outlet 12; high-pressure hydrogen outlet 13. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0032] The serial numbers of the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0033] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0034] The present invention provides an electrochemical hydrogen pump for preparing high-pressure hydrogen. By adopting a multi-stage electrochemical hydrogen pump series mode, that is, the applied direct current is in a series mode, and the positive and negative electrode gas chambers in the hydrogen pump are also in a series mode, the hydrogen pressure can be rapidly increased step by step. The technology has a wide range of applications, ranging from portable mobile hydrogen boosting equipment to fixed hydrogen refueling stations, and can also be used for high-purity hydrogen preparation equipment.

[0035] Specifically, the electrochemical hydrogen pump for preparing high-pressure hydrogen provided by the present invention includes a fixed end plate, an insulating plate, an electrode plate, a partitioning fixed plate, a gas-liquid transmission plate and a membrane electrode assembly that are fixedly connected as one. The gas-liquid transmission plate is fixedly connected to the partitioning fixed plate to form a gas chamber assembly. The partitioning fixed plate is used to support the gas-liquid transmission plate and seal the gas-liquid transmission plate. The gas-liquid transmission plate is a porous conductive plate to ensure the passage of hydrogen and water. There are multiple gas chamber assemblies, and the gas chamber assembly is arranged between two electrode plates. A membrane electrode assembly is arranged between any two adjacent gas chamber assemblies; two gas chamber assemblies and one membrane electrode assembly constitute a single-stage hydrogen pump, and multiple single-stage hydrogen pumps are connected in series to form a multi-stage electrochemical hydrogen pump, wherein electronic conduction and ion conduction are connected in series in sequence, and multiple gas chambers are connected in series in sequence to achieve step-by-step pressurization from low pressure to high pressure. There are two fixed end plates, insulating plates and electrode plates, and they are arranged oppositely. From the outside to the inside, they are fixed end plates, insulating plates and electrode plates.

[0036] In one embodiment, the thickness of the partition fixing plate and the gas-liquid transmission plate is the same, a mounting step is provided on the partition fixing plate, and a mounting boss is provided on the gas-liquid transmission plate, and the mounting boss is clamped on the mounting step to fix the gas-liquid transmission plate to the partition fixing plate. The gas chamber assembly forms a concave-convex structure composed of the mounting boss and the mounting step, which can effectively support the membrane electrode assembly so that the membrane electrode assembly does not deform under high pressure.

[0037] In one embodiment, a groove is provided on one or both sides of the partition fixing plate, the thickness of the gas-liquid transmission plate is equal to the depth of the groove, and the gas-liquid transmission plate is embedded in the groove and fixedly connected to the partition fixing plate. Since the groove structure does not penetrate the partition fixing plate, a through hole needs to be provided on the partition fixing plate, and the through hole is provided on the bottom surface of the groove so that the two sides of the partition fixing plate are connected, and the number of the through holes can be one or more.

[0038] In one of the embodiments, the through holes on the separation fixing plates between two adjacent air chamber components are staggered, and the staggered arrangement enables sufficient flow of gas and liquid.

[0039] In one embodiment, the electrode plate includes a positive plate and a negative plate, a low-pressure hydrogen inlet and a low-pressure hydrogen outlet are arranged on the fixed end plate close to the positive plate, and a high-pressure hydrogen outlet is arranged on the fixed end plate close to the negative plate.

[0040] In one embodiment, the gas-liquid transmission plate is a porous conductive metal plate or a porous conductive carbon plate, the porous space in the plate serves as the gas chamber of the hydrogen pump, and the porous space between two adjacent membrane electrode assemblies serves as the same gas chamber.

[0041] In one embodiment, the membrane electrode assembly includes a proton conducting membrane, a catalytic layer and a diffusion layer arranged from the inside to the outside, with the proton conducting membrane in the middle, the catalytic layers on both sides, and the diffusion layers on the two outer sides. The diffusion layer is connected to the gas-liquid transmission plate, and the catalytic layer can be directly placed on the proton conducting membrane or directly placed on the diffusion layer.

[0042] In one embodiment, carbon paper, carbon felt or other common porous conductive materials are provided between the membrane electrode assembly and the gas-liquid transmission plate to increase the supporting strength.

[0043] Based on the above embodiments, the electrochemical hydrogen pump for preparing high-pressure hydrogen provided by the present invention has at least the following advantages:

[0044] 1. The multi-stage electrochemical hydrogen pump for preparing high-pressure hydrogen has many advantages, such as compactness, high boosting efficiency, no maintenance and almost no noise due to the lack of mechanical moving parts;

[0045] 2. The porous gas-liquid transmission plate is used, and its inner pore space is directly used as the gas chamber, which reduces the gas space of the multi-stage electrochemical hydrogen pump, reduces the dead volume, increases the safety, and reduces the volume of the multi-stage hydrogen pump; at the same time, the contact area with the membrane electrode is increased, providing the best support for the membrane electrode, while increasing and reducing the ohmic impedance and improving the efficiency of the hydrogen pump;

[0046] 3. The separation fixing plate and the gas-liquid transmission plate are processed into corresponding convex and concave shapes to form an assembly, so that they can jointly bear the pressure difference on both sides of the membrane electrode, effectively support the membrane electrode, prevent it from deformation, and extend the stability and life of the membrane electrode and hydrogen pump;

[0047] 4. Multiple hydrogen pumps are connected in series to form a multi-stage electrochemical hydrogen pump. Electronic conduction and ion conduction are connected in series in sequence, and from the low-pressure gas chamber to the high-pressure gas chamber, they are connected in series in sequence to improve the boosting effect and reduce energy consumption.

[0048] 5. The structure is simple, easy to process and manufacture, suitable for large-scale production, which can greatly reduce costs, and at the same time make the assembly process and requirements relatively simple and easy to control. It can be used in portable mobile hydrogen boosting equipment and fixed hydrogen refueling stations, and can also be used in high-purity hydrogen preparation equipment.

[0049] Embodiment 1:

[0050] like Figure 1 and Figure 2As shown, a low-pressure hydrogen inlet 11 and a low-pressure hydrogen outlet 12 are processed on the fastening end plate 1, the insulating plate 3 and the positive plate 4 on one side, and a high-pressure hydrogen outlet 13 is processed on the fastening end plate 1, the insulating plate 3 and the negative plate 5 on the other side. Good sealing is done between the fastening end plate 1 and the insulating plate 3, between the insulating plate 3 and the electrode plates 4 and 5, and between the positive plate 4, the negative plate 5 and the partition fixing plate 6. Select the partition fixing plate original plate 6a with the same thickness as the gas-liquid transmission plate 7, process it into a built-in step shape 6, and process the gas-liquid transmission plate into a corresponding boss shape 7, as shown in FIG. Figure 1 As shown, the convex and concave separation fixing plate-gas-liquid transmission plate assembly effectively supports the membrane electrode assembly so that it does not deform under high pressure. The membrane electrode assembly 8 is prepared according to the conventional method of hydrogen-air fuel cells.

[0051] like Figure 2 As shown, the fastening end plate 1 on the low-pressure hydrogen side, the insulating plate 3, the positive plate 4, the first gas chamber assembly 6-7, the first membrane electrode assembly 8, the second gas chamber assembly 6-7, the second membrane electrode assembly 8, the third gas chamber assembly 6-7, the third membrane electrode assembly 8, the fourth gas chamber assembly 6-7, the fourth membrane electrode assembly 8, the fifth gas chamber assembly 6-7, the negative plate 5, the insulating plate 3, the fastening end plate 1 are assembled in sequence, and finally fastened with bolts 2 to assemble into a multi-stage electrochemical hydrogen pump. This embodiment is a four-stage electrochemical hydrogen pump.

[0052] A first air chamber is formed in the first air chamber assembly 6-7, and the internal pressure is P1; a second air chamber is formed in the second air chamber assembly 6-7, and the internal pressure is P2; a third chamber is formed in the third air chamber assembly 6-7, and the internal pressure is P3; a fourth air chamber is formed in the fourth air chamber assembly 6-7, and the internal pressure is P4; a fourth air chamber is formed in the fifth air chamber assembly 6-7, and the internal pressure is P5. Under the action of the external DC electric field, the hydrogen gas with a pressure of P1 in the first gas chamber is dissociated into protons under the action of the positive electrode electrocatalyst of the first membrane electrode assembly 8, and then passes through the proton conductive membrane in the first membrane electrode assembly 8, and then generates hydrogen gas with a pressure of P2 under the action of the negative electrode electrocatalyst on the other side of the first membrane electrode assembly 8. The hydrogen gas passes through the second gas chamber in the second gas chamber assembly 6-7 and reaches the positive electrode electrocatalyst of the second membrane electrode assembly 8, and then dissociates into protons and passes through the proton conductive membrane in the second membrane electrode assembly 8, and then generates hydrogen gas with a pressure of P3 under the action of the negative electrode electrocatalyst on the other side of the second membrane electrode assembly 8, and so on, and finally forms hydrogen gas with a pressure of P5 in the fifth gas chamber. Hydrogen is converted back and forth between hydrogen-proton-hydrogen, and conduction is converted back and forth between electron conduction-proton conduction-electron conduction. According to the above formula 1: E = (RT / 2F) ln (P2 / P2) + ir, under the action of the external electric field, after passing through the first hydrogen pump, the hydrogen pressure increases from P1 to P2; after passing through the second hydrogen pump, the hydrogen pressure increases from P2 to P3; and so on, the pressure is finally increased to P5. Since each pressurization process is exponential, a higher pressure can be reached through multiple stages of pressurization.

[0053] Embodiment 2:

[0054] like Figure 3 and Figure 4 As shown, the difference between this embodiment and embodiment 1 is that the air chamber components 6-7 are different. In this embodiment, the partition fixing plate original plate 6a is selected, and the concave platforms 6 are processed on both sides of the partition fixing plate, and through holes 9 and through holes 10 are processed on the partition fixing plate, and the gas-liquid transmission plate is processed and embedded in the concave platforms of the partition fixing plate. When a multi-stage hydrogen pump is used and multiple partition fixing plates are used, it is best to choose to stagger the gas-liquid channels processed on adjacent partition fixing plates so that the gas and liquid can flow fully. Under the premise of ensuring good support, the gas-liquid channel can be one or more.

[0055] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0056] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An electrochemical hydrogen pump for preparing high-pressure hydrogen, characterized in that: It includes a fixed end plate, an insulating plate, an electrode plate, a partition fixed plate, a gas-liquid transmission plate and a membrane electrode assembly that are fixedly connected as one. The gas-liquid transmission plate is a porous conductive plate. The gas-liquid transmission plate is fixedly connected to the partition fixed plate to form a gas chamber assembly; the number of the fixed end plate, the insulating plate and the electrode plate are two and they are arranged opposite to each other, and from the outside to the inside, they are the fixed end plate, the insulating plate and the electrode plate in sequence; the number of the gas chamber assemblies is multiple, the gas chamber assembly is arranged between two of the electrode plates, and one membrane electrode assembly is arranged between any two adjacent gas chamber assemblies. The two gas chamber assemblies and one membrane electrode assembly constitute a single-stage hydrogen pump, and multiple single-stage hydrogen pumps are connected in series to form a multi-stage electrochemical hydrogen pump, wherein electronic conduction and ion conduction are sequentially connected in series, and multiple gas chambers are sequentially connected in series; The partition fixing plate and the gas-liquid transmission plate have the same thickness, the partition fixing plate is provided with a mounting step, the gas-liquid transmission plate is provided with a mounting boss, the mounting boss is clamped to the mounting step so that the gas-liquid transmission plate is fixed to the partition fixing plate; A groove is provided on one side or both sides of the partition fixing plate, the thickness of the gas-liquid transmission plate is equal to the depth of the groove, the gas-liquid transmission plate is embedded in the groove and fixedly connected to the partition fixing plate; a through hole is provided on the partition fixing plate, and the through hole is opened on the bottom surface of the groove.

2. The electrochemical hydrogen pump for preparing high-pressure hydrogen according to claim 1, characterized in that: The through holes on the partition fixing plates of two adjacent air chamber components are staggered.

3. The electrochemical hydrogen pump for preparing high-pressure hydrogen according to any one of claims 1-2, characterized in that: The electrode plate includes a positive electrode plate and a negative electrode plate. A low-pressure hydrogen inlet and a low-pressure hydrogen outlet are arranged on the fixed end plate close to the positive electrode plate, and a high-pressure hydrogen outlet is arranged on the fixed end plate close to the negative electrode plate.

4. The electrochemical hydrogen pump for preparing high-pressure hydrogen according to any one of claims 1-2, characterized in that: The gas-liquid transmission plate is a porous conductive metal plate or a porous conductive carbon plate.

5. The electrochemical hydrogen pump for preparing high-pressure hydrogen according to any one of claims 1-2, characterized in that: The membrane electrode assembly comprises a proton conducting membrane, a catalytic layer and a diffusion layer which are arranged in sequence from the inside to the outside.

6. The electrochemical hydrogen pump for preparing high-pressure hydrogen according to any one of claims 1-2, characterized in that: Carbon paper, carbon felt or other common porous conductive materials are arranged between the membrane electrode assembly and the gas-liquid transmission plate.

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