High-temperature-resistant ceramic separation membrane and preparation and application thereof

Abstract

The application belongs to the technical field of separation membranes, and discloses a high-temperature-resistant ceramic separation membrane and a preparation and application thereof.A high-temperature-resistant ceramic separation membrane is obtained by sequentially performing acid etching, hydrophobic material soaking and irradiation cross-linking treatment on a tubular membrane or a hollow fiber membrane.The high-temperature-resistant ceramic membrane effectively realizes the separation of hydrogen and water vapor at high temperature, realizes the reuse of high-temperature water vapor, reduces the consumption of heat energy and water resources in the high-temperature water vapor electrolysis technology, and significantly reduces the production cost in the high-temperature water vapor electrolysis process.

Description

Technical Field

[0001] This invention belongs to the field of separation membrane technology, and specifically relates to a high-temperature resistant ceramic separation membrane and its preparation and application. Background Technology

[0002] In high-temperature water electrolysis for hydrogen production, the product hydrogen and some unelectrolyzed water vapor are discharged together from the electrolysis system. Therefore, hydrogen and water vapor separation technology is a crucial step in the hydrogen purification process. Currently, the main method involves cooling the high-temperature hydrogen and water vapor, condensing the water vapor, and then removing the moisture from the hydrogen through a steam-water separator and dryer. This process consumes a significant amount of energy. The unelectrolyzed water vapor is directly separated in the steam-water separator and discharged through the bottom waste outlet, resulting in a waste of water resources and thermal energy. Increased energy consumption leads to higher hydrogen production costs. A suitable high-temperature separation material and technology are needed to achieve the separation of hydrogen and water vapor.

[0003] Currently, the separation technologies for different gas components, different liquid components, and gas and liquid components are involved in fields such as chemical engineering, pharmaceuticals, and biology. Separation membranes, with their advantages of low energy consumption, low emissions, and small footprint, are increasingly used in processes separating different components. Ceramic membranes are a type of inorganic membrane, primarily using inorganic ceramic materials such as alumina, zirconium oxide, titanium dioxide, and silicon oxide as supports, which are then coated on the surface and sintered at high temperatures. Compared to traditional polymer separation membrane materials, ceramic membranes offer advantages such as good chemical stability, high temperature resistance, resistance to acids and alkalis, resistance to organic solvents, narrow pore size distribution, and high separation efficiency, making them more suitable for separating different components under high-temperature conditions. Summary of the Invention

[0004] In order to overcome the shortcomings and deficiencies of the prior art, the primary objective of this invention is to provide a method for preparing a high-temperature resistant dense ceramic separation membrane.

[0005] Another objective of this invention is to provide a high-temperature resistant ceramic separation membrane prepared by the above method.

[0006] Another object of the present invention is to provide the application of the above-mentioned high-temperature resistant ceramic separation membrane in hydrogen purification processes.

[0007] The objective of this invention is achieved through the following solution:

[0008] A method for preparing a high-temperature resistant ceramic separation membrane includes the following steps:

[0009] (1) Acid etching treatment is performed on tubular membranes or hollow fiber membranes;

[0010] (2) Immerse the tubular membrane or hollow fiber membrane obtained in step (1) in a hydrophobic material solution, take out the tubular membrane or hollow fiber membrane, and dry it to obtain a hydrophobic modified tubular membrane or hollow fiber membrane.

[0011] (3) The hydrophobic modified tubular membrane or hollow fiber membrane from step (2) is subjected to irradiation crosslinking treatment to obtain a high-temperature resistant ceramic separation membrane.

[0012] The tubular membrane or hollow fiber membrane mentioned in step (1) can be purchased directly or prepared through the following steps:

[0013] 1) Perovskite materials were prepared by at least one of the following methods: co-precipitation, sol-gel, and molten salt methods;

[0014] 2) Tubular membranes or hollow fiber membranes were prepared by extrusion process and phase change conversion method, respectively.

[0015] The preparation method of tubular membrane and hollow fiber membrane in step (1) specifically includes the following steps: EDTA, citric acid and metal ions are mixed, the pH is adjusted to 5-8 with nitric acid and ammonia, and stirred at 50-80°C until a gel is formed; the mixture is burned at 150-400°C to generate powder; the powder is extruded and then sintered at 800-1500°C to obtain tubular membrane or hollow fiber membrane;

[0016] The metal ions are provided by one of Ba(NO3)2 or Sr(NO3)2, Ce(NO3)3, and Ni(NO3)2; the molar ratio of Ba(NO3)2 or Sr(NO3)2, Ce(NO3)3, and Ni(NO3)2 is 1:1:0.1 to 1:1:0.5; the molar ratio of total metal ions: EDTA: citric acid is 1:1:2 to 1:2:4.

[0017] The acid mentioned in step (1) is one of sulfuric acid, nitric acid, or hydrochloric acid; the mass concentration of the acid is 50%-98%.

[0018] The acid etching process in step (1) takes 0.5 to 5 hours.

[0019] The hydrophobic material in step (2) includes at least one of polydimethylsiloxane, fluorosilicone resin, polytetrafluoroethylene, and polyethylene.

[0020] In step (2), the mass concentration of the hydrophobic material in the hydrophobic material solution is 50% to 60%.

[0021] The solvent for the hydrophobic material solution in step (2) is an organic solvent, preferably at least one of acetone, tetrahydrofuran, and n-hexane.

[0022] The soaking time in step (2) is 1 to 5 minutes; the drying is vacuum drying at a temperature of 40 to 70°C.

[0023] The irradiation crosslinking treatment in step (3) involves irradiating the hydrophobically modified membrane with at least one of X-rays or γ-rays for a treatment time of 10 to 30 minutes.

[0024] A high-temperature resistant dense ceramic separation membrane prepared by the above method.

[0025] The application of the above-mentioned high-temperature resistant dense ceramic separation membrane in hydrogen purification process.

[0026] The application of the high-temperature resistant dense ceramic separation membrane in the hydrogen purification process specifically includes the following steps:

[0027] A. High-temperature resistant ceramic separation membranes are bonded together using sealant to achieve the combination of separation membranes;

[0028] B. Assemble the combined ceramic membrane to obtain a high-temperature resistant membrane separation component, install the component on the membrane separation process, thereby realizing the application of the high-temperature resistant ceramic separation membrane in the hydrogen purification process;

[0029] The sealant mentioned in step A is at least one of silicone sealant and ceramic sealant.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] This invention prepares a membrane separation material suitable for hydrogen and water vapor under high temperature conditions. It eliminates the need for water vapor condensation, achieving a low-energy-consumption and high-efficiency separation and purification technology for hydrogen, making rational use of resources and reducing hydrogen production costs.

[0032] The high-temperature resistant ceramic separation membrane prepared by this invention can be applied to high-temperature membrane separation components in hydrogen purification processes. It combines high-temperature membrane separation technology with hydrophobic surface treatment and irradiation crosslinking techniques. The hydrophobic surface treatment effectively solves the problem of supersaturated water vapor condensing and accumulating on the surface of the high-temperature membrane separation component under high-temperature conditions, leading to a reduction in the effective area of ​​the membrane separation component and a severe decrease in hydrogen permeability. The irradiation crosslinking technique enhances the stability and temperature resistance of the polymer organic composite membrane on the surface. This enables the separation of hydrogen and high-temperature water vapor from high-temperature electrolysis products under high-temperature conditions, allowing for the reuse of the high-temperature water vapor. It also reduces the heat and water consumption in high-temperature water vapor electrolysis technology, significantly lowering the production cost of the high-temperature water vapor electrolysis process.

[0033] This invention can be applied to the hydrogen purification process in high-temperature water electrolysis for hydrogen production, and can also be applied to the purification of high-temperature, high-humidity, hydrogen-rich tail gas products from petrochemical enterprises. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the high-temperature hydrogen-water vapor membrane separator of the present invention. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. Unless otherwise specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments used, unless otherwise specified, are all commercially available conventional products.

[0036] Unless otherwise specified, all reagents used in the examples are commercially available.

[0037] like Figure 1 As shown, in the high-temperature water vapor membrane separator of this invention, hollow fiber membrane modules arranged like those in a shell-and-tube heat exchanger are filled inside. A high-temperature hydrogen-water vapor mixture enters the separator from the inlet. The high-temperature hydrogen selectively enters the hollow fiber membrane modules for separation. After being drawn in by a vacuum pump at the hydrogen outlet, a pressure difference exists between the inside and outside of the hollow fiber membrane. The specific pressure value depends on the power of the vacuum pump and the performance of the hollow fiber membrane. Residual high-temperature water vapor remaining in the shell flows out from the bottom of the membrane separator for reuse.

[0038] Example 1

[0039] Preparation of hollow fiber membranes:

[0040] EDTA and citric acid were used as complexing agents, and analytically pure Ba(NO3)2, Ce(NO3)3, and Ni(NO3)2 were used as metal ion sources. The molar ratio of Ba(NO3)2, Ce(NO3)3, and Ni(NO3)2 was 1:1:0.3, and the molar ratio of total metal ions to EDTA to citric acid was 1:1:3. The metal ion sources, EDTA, and citric acid were mixed, and the pH of the solution was adjusted to 6 using nitric acid and ammonia. The mixture was stirred at 70°C until a gel was formed, and then heated to 300°C in a furnace to generate a powder. The powder was extruded and sintered at 1000°C to obtain a hollow fiber membrane.

[0041] Preparation of high-temperature resistant dense ceramic separation membrane:

[0042] Hollow fiber membranes were immersed in 70% sulfuric acid for 1 hour to obtain acid-etched hollow fiber membranes. These membranes were then immersed in a 4:1 acetone mixture of polydimethylsiloxane (MW 9000–10000) and fluorosilicone resin (mass concentration >99.9%) for 3 minutes, with a total mass concentration of 60%. After removal, the membranes were dried under vacuum at 60°C to evaporate excess solvent. The hydrophobically treated hollow fiber membranes were then subjected to gamma irradiation for 20 minutes.

[0043] Applications of high-temperature resistant dense ceramic separation membranes:

[0044] The irradiated crosslinked hollow fiber membranes are bonded together using silicone adhesive. The treated membrane modules are then assembled to obtain high-temperature resistant membrane separation modules. After airtightness testing, they are installed on the membrane separation process, and insulation is provided for the corresponding operating temperature.

[0045] The experimental test results are shown in Table 1: S1 represents the membrane separation data of the hollow fiber membrane in Example 1 without surface hydrophobic treatment and irradiation crosslinking treatment; S2 represents the membrane separation data of the hollow fiber membrane in Example 1 after surface hydrophobic treatment; and S3 represents the membrane separation data of the hollow fiber membrane in Example 1 after surface hydrophobic treatment and irradiation crosslinking treatment. Compared with S1 and S2, the hydrogen volume ratio in the permeate gas of the hollow fiber membrane S3 after surface hydrophobic treatment and irradiation crosslinking treatment is significantly increased. This effectively solves the problem of water vapor droplets adsorbing onto the surface of the hollow fiber membrane during hydrogen purification, leading to a decrease in membrane separation performance, and further enhances the separation performance of the hollow fiber membrane.

[0046] Table 1. Membrane separation performance data of laboratory-synthesized hollow fiber membranes before and after treatment.

[0047]

[0048] Example 2

[0049] Preparation of high-temperature resistant dense ceramic separation membrane:

[0050] A commercially available tubular membrane (purchased from Pulang Membrane) was placed in 70% sulfuric acid for 2 hours to obtain an acid-etched tubular membrane. The acid-etched tubular membrane was then placed in a 50% tetrahydrofuran emulsion of polytetrafluoroethylene (99.9% concentration, particle size 1-10 μm) for 2 minutes. After removal, it was dried at 70°C under vacuum to evaporate excess solvent. The hydrophobically treated tubular membrane was then subjected to X-ray irradiation for 30 minutes.

[0051] Applications of high-temperature resistant dense ceramic separation membranes:

[0052] After irradiation crosslinking treatment, the tubular membranes are bonded together using silicone sealant. The treated membrane modules are then assembled to obtain high-temperature resistant membrane separation modules. After airtightness testing, they are installed on the membrane separation process, and insulation is provided for the corresponding operating temperature.

[0053] The experimental test results are shown in Table 2: S1 represents the membrane separation data of the tubular membrane in Example 2 without surface hydrophobic treatment and irradiation crosslinking treatment; S2 represents the membrane separation data of the tubular membrane with surface hydrophobic treatment; and S3 represents the membrane separation data of the tubular membrane with surface hydrophobic treatment and irradiation crosslinking treatment. Compared with S1 and S2, the volume ratio of hydrogen in the permeate gas of the tubular membrane S3 after surface hydrophobic treatment and irradiation crosslinking treatment is significantly increased. This effectively solves the problem of water vapor droplets adsorbing onto the surface of the tubular membrane during hydrogen purification, leading to a decrease in membrane separation performance, and further enhances the separation performance of the tubular membrane.

[0054] Table 2. Membrane separation performance data of commercially available tubular membrane treatment before and after treatment.

[0055]

[0056] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. The application of a high-temperature resistant ceramic separation membrane in the hydrogen purification process of high-temperature water electrolysis for hydrogen production, characterized in that, The preparation of the high-temperature resistant ceramic separation membrane includes the following steps: (1) Acid etching treatment is performed on tubular membranes or hollow fiber membranes; The acid is one of sulfuric acid, nitric acid, or hydrochloric acid; the mass concentration of the acid is 50%-98%. The acid etching process takes 0.5 to 5 hours. The preparation method of the tubular membrane and hollow fiber membrane specifically includes the following steps: mixing EDTA, citric acid, and metal ions, adjusting the pH to 5-8 with nitric acid and ammonia, and stirring at 50-80°C until a gel is formed; burning at 150-400°C to generate powder; extruding the powder into shape, and then sintering at high temperature at 800-1500°C to obtain a tubular membrane or hollow fiber membrane; (2) Immerse the tubular membrane or hollow fiber membrane obtained in step (1) in a hydrophobic material solution, take out the tubular membrane or hollow fiber membrane, and dry it to obtain a hydrophobic modified tubular membrane or hollow fiber membrane. The hydrophobic material includes at least one of polydimethylsiloxane, fluorosilicone resin, polytetrafluoroethylene, and polyethylene; the mass concentration of the hydrophobic material in the solution is 50% to 60%; and the soaking time is 1 to 5 minutes. (3) The hydrophobic modified tubular membrane or hollow fiber membrane from step (2) is subjected to irradiation crosslinking treatment to obtain a high-temperature resistant ceramic separation membrane. The irradiation crosslinking treatment involves irradiating the hydrophobically modified membrane with at least one of X-rays or γ-rays for a duration of 10-30 minutes.

2. The application according to claim 1, characterized in that: The metal ions in step (1) are provided by one of Ba(NO3)2 or Sr(NO3)2, Ce(NO3)3, and Ni(NO3)2; the molar ratio of Ba(NO3)2 or Sr(NO3)2, Ce(NO3)3, and Ni(NO3)2 is 1:1:0.1 to 1:1:0.5; the molar ratio of total metal ions: EDTA: citric acid is 1:1:2 to 1:2:

4.

3. The application according to claim 1, characterized in that: The solvent for the hydrophobic material solution in step (2) is at least one of acetone, tetrahydrofuran, and n-hexane.

4. The application according to claim 1, characterized in that, Specifically, the following steps are included: A. High-temperature resistant ceramic separation membranes are bonded together using sealant to achieve the combination of separation membranes; B. Assemble the combined ceramic membrane to obtain a high-temperature resistant membrane separation component. Install the component on the membrane separation process to realize the application of the high-temperature resistant ceramic separation membrane in the hydrogen purification process of high-temperature water electrolysis for hydrogen production. The sealant mentioned in step A is at least one of silicone sealant and ceramic sealant.

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