Device for preparing water electrolysis hydrogen production composite diaphragm

Abstract

The device for preparing the electrolytic water hydrogen production composite diaphragm comprises 1) a stirring mechanism which is used for being connected with a raw material supply system and mixing raw materials to obtain a membrane casting solution, 2) a coating mechanism which is used for coating a base membrane with the membrane casting solution; the gas phase inversion mechanism is used for evaporating part of the solvent in the membrane casting solution and forming compact holes in the surface of the base membrane; the freeze drying mechanism comprises a freezing area, a vacuum drying area and a liquid nitrogen storage tank; and (5) the winding mechanism is used for receiving the dried composite diaphragm from the vacuum drying area and winding the composite diaphragm into a roll shape. Through combination of a gas phase inversion technology and a freeze drying method, the composite diaphragm with compact and uniform pore channels is obtained, the diameter of the pore channels is accurately controlled to be 100 nm or below, and the bubble point pressure rises to be higher than 3 bar and is far higher than the industrial standard. According to the invention, uniform distribution of the inorganic hydrophilic material in the diaphragm is also realized, and the comprehensive performance of the diaphragm is further enhanced, so that the diaphragm can maintain excellent stability and durability in a complex electrolytic environment.

Description

Technical Field

[0001] This utility model relates to the field of water electrolysis for hydrogen production technology, specifically an apparatus for preparing a composite membrane for water electrolysis for hydrogen production. Background Technology

[0002] Hydrogen-producing composite membranes for water electrolysis are typically composed of multiple materials. Taking the novel alkaline water electrolysis composite membrane independently developed by Carbon Energy Technology as an example, its material composition includes organic polymers, inorganic ceramic powders, and an inner lining support. This composite material can meet various performance requirements of the membrane, such as chemical stability, physical stability, hydrophilicity, and ionic conductivity.

[0003] The composite diaphragm for hydrogen production via water electrolysis is mainly used in alkaline electrolyzers to separate the cathode and anode, preventing the mixing of hydrogen and oxygen while allowing the free movement of ions within the electrolyzer's circuitry. Its main functions include: gas isolation, strictly separating the hydrogen produced at the cathode from the oxygen produced at the anode to prevent safety hazards caused by gas mixing; and ion conduction, allowing the free movement of ions (such as potassium ions and hydroxide ions) within the electrolyzer's circuitry, ensuring the smooth operation of the electrolysis process.

[0004] In existing technologies, the preparation method of composite membranes for water electrolysis to produce hydrogen is shown in patent CN115803477A. ​​This involves coating both sides of a base membrane with a slurry, followed by a two-step phase separation process using gas-phase inversion (VIPS) and liquid-phase inversion (LIPS) to prepare a membrane with dense pores. However, in engineering practice, problems such as large membrane width and uneven phase transformation conditions lead to uneven dispersion of inorganic materials and non-uniform pores in the prepared composite membrane. Consequently, it is prone to defects such as cracking and high hydrogen permeability during water electrolysis to produce hydrogen.

[0005] Furthermore, this method uses water as a liquid phase transformation separation method. During the liquid phase transformation process, water and solvent in the membrane will exchange, and the solvent will be extracted from the water to form dense channels. However, during the scale-up process, the exchange between water and solvent is a slow process, so the prepared pore size distribution is wide and there are large pores, resulting in a low bubble point pressure (typically 2-3 bar) and high hydrogen permeability. Utility Model Content

[0006] To address the shortcomings of existing technologies, this invention provides an apparatus for preparing a composite membrane for hydrogen production via water electrolysis, comprising:

[0007] —A stirring mechanism is used to connect with the raw material supply system to mix the raw materials to obtain the casting solution;

[0008] —A coating mechanism used to coat the coating solution onto the base film;

[0009] a gas phase phase inversion mechanism for evaporating part of the solvent in the casting solution to form a dense hole on the surface of the base film;

[0010] a freeze-drying mechanism including a freezing area, a vacuum drying area and a liquid nitrogen storage tank;

[0011] a winding mechanism for receiving the dried composite diaphragm from the vacuum drying area and winding it into a roll.

[0012] In a preferred embodiment, the freezing area is connected to the output end of the gas phase phase inversion area for freezing the solvent in the casting solution coated on the surface of the base film; the vacuum drying area is connected to the output end of the freezing area to remove the solvent in the casting solution coated on the surface of the base film by sublimation; the liquid nitrogen storage tank is connected to the freezing area to provide a low-temperature environment for the freezing area.

[0013] In a preferred embodiment, the gas phase phase inversion mechanism includes a gas phase phase inversion area and a water vapor storage tank; wherein:

[0014] the gas phase phase inversion area is connected to the output end of the film head for evaporating part of the solvent in the casting solution to form a dense hole on the surface of the base film,

[0015] the water vapor storage tank is connected to the gas phase phase inversion area for providing the gas phase phase inversion area with a preset temperature and a preset humidity.

[0016] In a preferred embodiment, the stirring mechanism includes a vacuum pump and a stirring tank, wherein:

[0017] the stirring tank is connected to the raw material supply system for mixing the raw materials to obtain a mixed slurry,

[0018] the vacuum pump is connected to the stirring tank for vacuum defoaming treatment of the mixed slurry in the stirring tank to obtain a casting solution.

[0019] In a preferred embodiment, the coating mechanism includes a base film unwinding member and a film head, wherein: the base film unwinding member is used to provide a base film to be coated,

[0020] the film head receives the casting solution treated by the vacuum pump from the stirring tank and coats the base film provided by the base film unwinding member;

[0021] Preferably, the raw materials include inorganic powder, resin and poor solvent.

[0022] Preferably, the inorganic powder is inorganic hydrophilic powder, for example, the inorganic hydrophilic powder can be one or a combination of ultra-fine silicon oxide, bentonite, diatomite, iron oxide, boehmite, aluminum hydroxide and zirconium oxide.

[0023] Preferably, the resin can be one or several of polyphenylene sulfide, polysulfone, polyethersulfone, polyimide, polyether ether ketone, polyvinylidene fluoride, polyolefin, or a high molecular alloy composed of one or several of them.

[0024] More preferably, the resin constitutes the membrane matrix.

[0025] More preferably, the membrane matrix can be one or more (two or more) layers of resin.

[0026] More preferably, the resin can be a polyolefin matrix.

[0027] In particular, the polyolefin matrix can be a polyethylene membrane matrix, a polypropylene membrane matrix, a polyethylene-polypropylene double-layer membrane matrix, or a polyethylene-polypropylene-polyethylene three-layer membrane matrix.

[0028] Preferably, the poor solvent includes one or more of water, alcohol, ether, ester, ketone, nitrile, alkane, halogenated hydrocarbon, aromatic hydrocarbon, and is preferably a solvent selected from one or more combinations of water, N,N-dimethylformamide, methanol, ethanol, diethyl ether, tetrahydrofuran, acetonitrile, valeronitrile, methoxypropionitrile, butyronitrile, adiponitrile, phenylacetonitrile, chloroacetonitrile, acetone, cyclohexane, dichloromethane, chloroform, carbon tetrachloride, ethyl acetate, acetone, N-methylpyrrolidone, toluene, and petroleum ether.

[0029] Preferably, the raw material further includes an organic binder.

[0030] More preferably, the organic binder is at least one of polyvinyl alcohol, polytetrafluoroethylene, polyvinylidene fluoride, modified styrene-butadiene rubber (modified SBR), fluorinated rubber, and polyurethane.

[0031] Preferably, the coating thickness of the membrane head on both sides of the base film is 50-500 μm, preferably 80-400 μm, and more preferably 100-300 μm.

[0032] Preferably, the temperature of the gas phase phase inversion zone is 5-150°C, preferably 10-120°C, and more preferably 15-100°C.

[0033] Preferably, the relative humidity of the gas phase phase inversion zone is 20-150% RH, preferably 30-120% RH, and more preferably 50-100% RH.

[0034] Preferably, the residence time of the base film coated with the casting solution in the gas phase phase inversion zone is 5-500 s, preferably 5-400 s, and more preferably 5-300 s.

[0035] Preferably, the temperature of the freezing area is -150℃ to -30℃, preferably -120℃ to -40℃, more preferably -100℃ to -60℃.

[0036] Preferably, the residence time of the base film coated with the casting solution in the freezing area is 2-30min, preferably 3-20min, more preferably 5-10min.

[0037] Preferably, the temperature of the vacuum drying is controlled at 60-100℃.

[0038] In a preferred embodiment, the method of using the device, the steps include:

[0039] Mixing and defoaming the raw materials using a stirred tank and a vacuum pump to obtain a casting solution;

[0040] Coating the casting solution to both sides of the base film through a film head;

[0041] Transferring the base film coated with the casting solution to the gas phase phase inversion area, adjusting the temperature, humidity of the gas phase phase inversion area and the residence time of the base film, so that a dense pore structure is formed on the surface of the base film;

[0042] Transferring the base film to the freezing area, adjusting the temperature of the freezing area and the residence time of the base film, and freezing the solvent of the casting solution on the surface of the base film;

[0043] Transferring the base film to the vacuum drying area, and removing the solvent of the casting solution coated on the surface of the base film by sublimation to obtain a coated membrane, i.e. the electrolytic water hydrogen composite membrane

[0044] The coated membrane is arranged and wound by a winding mechanism.

[0045] Preferably, the mixing and defoaming steps include:

[0046] Mixing the inorganic hydrophilic powder, resin, poor solvent and other raw materials uniformly in a stirred tank, and then performing vacuum defoaming treatment by a vacuum pump to obtain a casting solution.

[0047] More preferably, the thickness of the coated film is 50-500μm, preferably 80-400μm, more preferably 100-300μm.

[0048] Preferably, the temperature of the gas phase phase inversion area is 5-150℃, preferably 10-120℃, more preferably 15-100℃.

[0049] Preferably, the relative humidity of the gas phase phase inversion area is 20-150% RH, preferably 30-120% RH, more preferably 50-100% RH.

[0050] Preferably, the base film coated with the casting solution has a residence time in the gas phase phase inversion zone of 5-500s, preferably 5-400s, more preferably 5-300s.

[0051] Preferably, the temperature of the freezing zone is -150℃ to -30℃, preferably -120℃ to -40℃, more preferably -100℃ to -60℃.

[0052] Preferably, the base film coated with the casting solution has a residence time in the freezing zone of 2-30min, preferably 3-20min, more preferably 5-10min.

[0053] Preferably, the temperature of the vacuum drying is controlled at 60-100℃.

[0054] The beneficial effects of the present application are:

[0055] The utility model provides a device for preparing electrolytic water hydrogen composite diaphragm, through the combination of gas phase phase inversion technology and freeze drying method, the optimization preparation process has obtained the composite diaphragm of dense and even pore. BRIEF DESCRIPTION OF DRAWINGS

[0056] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiment or prior art description will be briefly introduced below, and obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creating creative labor.

[0057] Figure 1 It is the device structure schematic diagram of the utility model embodiment 1.

[0058] The reference signs are explained as follows: 101, vacuum pump; 102, stirred tank; 103, membrane head; 104, gas phase phase inversion zone; 105, freezing zone; 106, vacuum drying zone; 107, winding mechanism; 108, water vapor storage tank; 109, liquid nitrogen storage tank; 110, base film unwinding component. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the scope of the present application.

[0060] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship, movement condition, etc. between components in a certain specific posture (as shown in the drawings), and if the specific posture changes, the directional indications also change accordingly.

[0061] In the present application, unless otherwise explicitly specified and limited, the terms "connection", "fixation" and the like should be understood in a broad sense, for example, "fixation" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be direct connection, or indirect connection through an intermediate medium; can be internal communication of two elements or interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0062] In addition, if the embodiments of the present application involve "first", "second" and the like, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features with "first", "second" can explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. For example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of those skilled in the art, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the scope of protection required by the present application.

[0063] Embodiment 1

[0064] The present embodiment provides a device for preparing an electrolytic water hydrogen production composite diaphragm, as shown in the figure, comprising: a stirring mechanism, a coating mechanism, a gas phase phase inversion mechanism, a freeze-drying mechanism, and a winding mechanism. Figure 1

[0065] ​The stirring mechanism is connected with the raw material supply system to mix the raw materials to obtain the casting solution. For example, the stirring mechanism can include a stirring tank 102 and a vacuum pump 101.

[0066] The stirring tank 102 is equipped with a stirring paddle to ensure that the raw materials (such as inorganic hydrophilic powder, resin, poor solvent and organic binder) are fully mixed to form a uniform mixed slurry.

[0067] The vacuum pump 101 is used to perform deep vacuum degassing treatment on the mixed slurry to remove bubbles in the slurry and ensure the high quality of the casting solution.

[0068] The coating mechanism is used to coat the casting solution onto the base film. For example, the coating mechanism can include a base film unwinding member 110 and a film head 103.

[0069] The film head 103 is used to ensure that the casting solution is uniformly coated on both sides of the base film with a thickness controlled within the range of 100-300 μm to achieve the best coating effect.

[0070] The base film unwinding mechanism 110 operates stably to ensure that the base film is released smoothly without wrinkles or stretching.

[0071] The gas phase phase inversion mechanism is used to evaporate part of the solvent in the casting solution to form a dense pore on the surface of the base film. For example, the gas phase phase inversion mechanism can include a gas phase phase inversion area 104 and a water vapor storage tank 108.

[0072] The gas phase phase inversion area 104 is designed as a sealed and controllable temperature and humidity environment and is equipped with a precise temperature and humidity control system. The temperature is set between 10-100℃ and the relative humidity is maintained at 50-100% RH to optimize the formation of the pore structure. The residence time of the base film in the gas phase phase inversion area is accurately controlled within 5-300s to ensure the density and uniformity of the pore structure.

[0073] The water vapor storage tank 108 maintains the temperature and humidity of the gas phase phase inversion area 104.

[0074] The freeze-drying mechanism includes a freezing area 105, a vacuum drying area 106 and a liquid nitrogen storage tank 109.

[0075] The freezing area 105 creates a low-temperature environment through the liquid nitrogen storage tank and uses liquid nitrogen rapid cooling technology to control the temperature within -100℃ to -60℃ to ensure that the solvent is frozen quickly.

[0076] The vacuum drying area 106 performs vacuum sublimation drying on the solvent.

[0077] The present patent can effectively avoid the influence of high temperature on the dispersibility of raw materials in traditional high temperature drying, and remove residual solvents.

[0078] The winding mechanism 107 is used to receive the composite diaphragm after drying in the vacuum drying area and wind it into a roll. For example, a high-precision winding device can be used to ensure that the coated diaphragm is wound flat and wrinkle-free, facilitating subsequent processing and storage.

[0079] Embodiment 2

[0080] The present embodiment provides a method for using the device described in embodiment 1.

[0081] The selection of raw materials is as follows:

[0082] (1) Inorganic hydrophilic powder: a combination of ultra-fine silicon oxide and bentonite is selected to improve the hydrophilicity and mechanical strength of the diaphragm.

[0083] (2) Resin: a high molecular alloy of polyphenylene sulfide and polyether sulfone is used as the base material to ensure the chemical corrosion resistance and thermal stability of the diaphragm.

[0084] (3) Poor solvent: a mixture of water and N,N-dimethylformamide is selected to optimize the dissolution effect and subsequent drying process.

[0085] (4) Organic binder: an appropriate amount of polyvinyl alcohol is added as a binder to improve the overall bonding strength of the diaphragm.

[0086] The steps of the method for use include:

[0087] S1, mixing and degassing: the selected raw materials are added to the stirring kettle 102 in proportion, thoroughly stirred and mixed, and then deep degassing is performed using the vacuum pump 101 to obtain high-quality casting solution.

[0088] S2, coating: the casting solution is uniformly coated on both sides of the base film through the film head 103, and the coating thickness is controlled to be 100-300 μm.

[0089] S3, gas phase transformation: the base film coated with the casting solution is transferred to the gas phase transformation area 104, and the pore structure is formed according to the preset temperature and humidity conditions and residence time.

[0090] S4, freezing and drying: the base film obtained in S3 is then subjected to rapid freezing of the solvent in the freezing area 105, and then low-temperature sublimation drying in the vacuum drying area 106 to completely remove the residual solvent.

[0091] S5, winding: the composite diaphragm dried in S4 is arranged and wound by the winding mechanism 107 to obtain the finished diaphragm, i.e. the composite diaphragm for electrolytic water hydrogen production.

[0092] The above merely describes preferred embodiments of the present application, and is not intended to limit the patent scope of the present application, and any equivalent structural transformation or direct / indirect application in other related technical fields under the inventive concept of the present application, as described in the present application specification and drawings, is included in the patent protection scope of the present application.

Claims

1. An apparatus for preparing a composite separator for hydrogen production by electrolysis of water, characterized by, The application relates to a composite diaphragm production device, which comprises: a stirring mechanism connected with a raw material supply system, which is used for mixing raw materials to obtain casting solution; a coating mechanism, which is used for coating the casting solution on a base film; a gas phase phase inversion mechanism, which is used for evaporating part of the solvent in the casting solution to form a dense hole on the surface of the base film; a freeze-drying mechanism, which comprises a freezing area, a vacuum drying area and a liquid nitrogen storage tank; the freezing area is connected with the output end of the gas phase phase inversion area and is used for freezing the solvent in the casting solution coated on the surface of the base film; the vacuum drying area is connected with the output end of the freezing area and is used for removing the solvent in the casting solution coated on the surface of the base film in a sublimation mode; the liquid nitrogen storage tank is connected with the freezing area and is used for providing a low-temperature environment for the freezing area; a winding mechanism, which receives the dried composite diaphragm from the vacuum drying area and winds the composite diaphragm into a roll.

2. The apparatus of claim 1, wherein, The gas phase phase inversion mechanism comprises a gas phase phase inversion area and a water vapor storage tank; the gas phase phase inversion area is connected with the output end of the film head and is used for evaporating part of the solvent in the casting solution to form a dense hole on the surface of the base film, the water vapor storage tank is connected with the gas phase phase inversion area and is used for providing a preset temperature and a preset humidity for the gas phase phase inversion area.

3. The apparatus of claim 1, wherein, The stirring mechanism comprises a vacuum pump and a stirring kettle, the stirring kettle is connected with the raw material supply system and is used for mixing raw materials to obtain mixed slurry, the vacuum pump is connected with the stirring kettle and is used for performing vacuum defoaming treatment on the mixed slurry in the stirring kettle to obtain casting solution.

4. The apparatus of claim 1, wherein, The coating mechanism comprises a base film unwinding member and a film head, the base film unwinding member is used for providing a base film to be coated, the film head receives the casting solution treated by the stirring kettle and the vacuum pump and coats the base film provided by the base film unwinding member.

5. The apparatus of claim 1, wherein, The raw materials comprise inorganic powder, resin and poor solvent.

6. The apparatus of claim 5, wherein, The resin constitutes a diaphragm base body; the diaphragm base body comprises one or more layers of resin.

7. The apparatus of claim 4, wherein, The coating thickness of the film head on both sides of the base film is 100-300 mu m.

8. The apparatus of claim 1, wherein, The temperature of the gas phase phase inversion area is 10-100 DEG C; the relative humidity of the gas phase phase inversion area is 50-100% RH; the residence time of the base film coated with the casting solution in the gas phase phase inversion area is 5-300 s.

9. The apparatus of claim 1, wherein, The temperature of the freezing area is -100 DEG C to -60 DEG C; the residence time of the base film coated with the casting solution in the freezing area is 5-10 min.

10. The apparatus of claim 1, wherein, The temperature of the vacuum drying is controlled in the range of 60-100 DEG C.

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