Alkaline electrolytic hydrogen diaphragm and production method thereof

Abstract

The invention discloses an alkaline electrolytic hydrogen diaphragm and a production method thereof, and the production method comprises the following steps: respectively pulping and dispersing PPS fibers with different forms according to a ratio to obtain PPS fibers with different specifications; according to the requirements and the use mode of the electrolytic hydrogen diaphragm, the PPS fibers, the PPS short fiber pulp and the PPS pulp of various specifications are controlled to be added, the PPS fibers, the PPS short fiber pulp and the PPS pulp are proportioned and dispersed according to the content, and auxiliary materials are added in the pulp blending process to achieve the auxiliary effects of dispersing and wet bonding. And then carrying out a short papermaking process to obtain a formed wet film, carrying out vacuum and squeezing dehydration on the papermaking wet film, drying the papermaking wet film in a drying cylinder, carrying out high-temperature hot pressing to form a film, and carrying out hydrophilic modification treatment to obtain the alkaline electrolytic hydrogen diaphragm. The effects of low quantification, high film forming strength, high temperature resistance, alkali resistance, good hydrophilicity, good air tightness and good durability are achieved.

Description

Technical Field

[0001] The present invention relates to a production method for preparing an alkaline hydrogen electrolysis diaphragm by wet papermaking, and in particular to a diaphragm preparation method with simple preparation process, high mechanical strength, burst resistance, alkali resistance, low resistance and high air tightness. Background Art

[0002] As the energy crisis and environmental pollution become increasingly serious, people are looking for clean and renewable new energy. Hydrogen energy, with its green, efficient, storable and transportable characteristics, has received widespread attention and application in the fields of electronics, military industry, transportation, chemical industry, etc. The green hydrogen produced by water electrolysis technology can achieve true zero emissions and will occupy a large proportion in the future hydrogen production field.

[0003] The technology of hydrogen production by water electrolysis is divided into alkaline water electrolysis, proton exchange membrane water electrolysis, solid oxide water electrolysis, and anion exchange membrane water electrolysis. Currently, the most widely used and most efficient one is alkaline water electrolysis hydrogen production, and the diaphragm is a key component of alkaline hydrogen electrolysis. Asbestos diaphragm was the earliest alkaline hydrogen electrolysis diaphragm, but due to its high resistance and poor airtightness, it is easy to dissolve in the electrolyte at high temperature to cause pollution, and asbestos is carcinogenic, so people began to look for various alternatives to asbestos diaphragms as alkaline hydrogen electrolysis diaphragms.

[0004] Polyphenylene sulfide diaphragms have good corrosion resistance and high temperature resistance, and are fully capable of being used as diaphragms for alkaline electrolysis of hydrogen. However, due to its poor solubility in organic solvents, polyphenylene sulfide diaphragms are mostly prepared by fiber weaving and other means, including needle-punched nonwoven polyphenylene sulfide diaphragms, and polyphenylene sulfide diaphragms prepared by melt-blowing. At the same time, polyphenylene sulfide has poor hydrophilicity, and the surface of the diaphragm is prone to produce more bubbles during use, resulting in a higher resistance of the diaphragm, and many methods are used to hydrophilize it. By blending polyphenylene sulfide fibers with vinylon fibers, sulfonating polyphenylene sulfide nonwoven fabrics with 90% to 98% H2SO4 at 70 to 120°C, modifying polyphenylene sulfide resins with inorganic nanoparticles, and spinning and weaving fibers into cloth through melt spinning. Summary of the invention

[0005] The object of the present invention is to provide an alkaline hydrogen electrolysis diaphragm and a production method thereof, specifically an alkaline hydrogen electrolysis diaphragm with high film strength, alkali resistance, good hydrophilicity and high air tightness.

[0006] The present invention provides an alkaline hydrogen electrolysis diaphragm and a production method thereof. PPS fibers of different forms are pulped and dispersed in different proportions to obtain PPS fibers of different specifications. According to the requirements and usage of the hydrogen electrolysis diaphragm, PPS fibers, PPS short fiber pulp and PPS pulp of various specifications are added, and the PPS fibers, PPS short fiber pulp and PPS pulp are proportioned and dispersed according to the content. When mixing the slurry, auxiliary materials are added to play an auxiliary role of dispersion and wet bonding. Then, a formed wet film is obtained through a short papermaking process. The wet film is vacuum and pressed for dehydration, dried by a drying cylinder, and formed into a film by high temperature hot pressing. Then, it is subjected to hydrophilic modification treatment to form an alkaline hydrogen electrolysis diaphragm. The effects of low quantitative, high film strength, high temperature resistance, alkali resistance, good hydrophilicity, good air tightness and good durability are achieved.

[0007] The PPS pulp is made of PPS pulp with an average diameter of 2 μm, which is beaten in a trough beater at a concentration of 1% to 5%, and the beating time is controlled to be 40 to 60 minutes until the average length of the pulp fiber cut is less than about 2 mm. The PPS staple fiber pulp is made of 0.89D filaments, which are beaten in a beater at a concentration of 1% to 5%, and the beating degree is controlled to be 55±3°SR. The PPS fiber is made of 0.89D*6mm or 3.2D*8mm PPS staple fiber or a composite of two staple fibers, which is dispersed at a high speed of 1% to 5% for 10 minutes in a high-speed disperser. The PPS pulp accounts for 30% to 70%, the PPS staple fiber pulp accounts for 30% to 70%, and the PPS fiber accounts for 30% to 70%.

[0008] Furthermore, when preparing the pulp, the solid content of the dispersed pulp prepared by the PPS fiber, the PPS short fiber pulp and the PPS pulp is 0.2% to 0.6%.

[0009] Furthermore, in the short papermaking process, the total solid content of the added PPS fibers, PPS staple pulp and PPS pulp is 0.02% to 0.05%.

[0010] The drying process of the drying cylinder controls the temperature to be 80-95°C for drying.

[0011] In the high temperature hot pressing film forming process, the embryonic membrane is hot pressed at a high temperature of 150° C. to 280° C. to form the film, and the hot pressing line pressure is controlled to be not less than 20 to 50 KN / m to form the film.

[0012] Compared with the prior art, the excellent effects of the present invention are embodied in:

[0013] The membrane is made by composite papermaking of various pulps and fibers, and the prepared membrane has a higher porosity and a lower pore size, so that the membrane has a lower resistance and a higher air tightness.

[0014] The diaphragm after hot pressing treatment has good mechanical strength and high burst resistance, and can adapt to the working environment of alkaline hydrogen electrolysis.

[0015] The wet papermaking membrane making process is simple and has good industrial application prospects. DETAILED DESCRIPTION

[0016] The present invention is further described below by way of examples, but the present invention is not limited to the implementation cases.

[0017] Example 1

[0018] Diaphragm used for alkaline electrolytic hydrogen electrolyzer. Its main requirements are: low quantitative, high film strength, high temperature resistance, alkali resistance, good hydrophilicity, good air tightness, good durability, etc. PPS pulp with an average diameter of 2μm is used for pulping in a trough beater, with a concentration of 2%. The pulping time is controlled for 50min until the average length of the pulp fiber is cut less than about 2mm. 0.89D*6mm and 3.2D*8mm short fibers are dispersed at a high speed of 2% for 10min in a high-speed disperser at a weight ratio of 3:7 for use. 40% pulp + 60% short fibers are mixed and prepared into a dispersed slurry with a concentration of 0.5% according to the total amount (net weight). Add 0.035% (solid content) of the total fiber pulp, add to the pulp pool or add continuously through the high-level box, and dilute to a concentration of 0.4% PAM and PEO compound dispersant (PAM+PEO compound, compounding process: 1000mL water gradually adds 1g PEO to dissolve and stir for 40 minutes, then gradually adds 3g PAM and continues to stir and dissolve for 90 minutes for standby use). The wet film embryo is formed through a circular net or an inclined net, and is dehydrated by vacuum suction and squeezing, and enters a drying cylinder group controlled at 85°C for drying. After drying, the film is hot-pressed in a high-temperature oven at 230±10°C to form a film, and the hot pressing line pressure is controlled to be not less than 20KN / m. After film formation, the film is treated with plasma for hydrophilicity.

[0019] Example 1 Experimental data table

[0020]

[0021] Example 2

[0022] Diaphragm used for alkaline electrolytic hydrogen electrolyzer. Its main requirements are: low quantitative, high film strength, high temperature resistance, alkali resistance, good hydrophilicity, good air tightness, good durability, etc. PPS pulp with an average diameter of 2μm is used for pulping in a trough beater with a concentration of 2%. The pulping time is controlled for 40min until the average length of the pulp fiber is cut less than about 2mm. 0.89D*6mm PPS short fibers are dispersed at a high speed of 2% for 10min in a high-speed disperser for use. 50% pulp + 50% short fibers are mixed and prepared into a dispersed slurry with a concentration of 0.3% according to the total amount (net weight). Add 0.03% (solid content) of the total fiber pulp, add to the pulp pool or add continuously through the high-level box, dilute the concentration of 0.4% PAM and PEO compound dispersant (PAM+PEO compound, compounding process: 1000mL water gradually adds 1g PEO to dissolve and stir for 40min, then gradually adds 3g PAM and continues to stir and dissolve for 90min for standby use). Form the wet film embryo through the round net or inclined net, through vacuum suction and squeezing dehydration, enter the drying cylinder group controlled at 90℃ for drying, and after drying, the embryo film is hot-pressed at 220±10℃ to form a film, and the hot pressing line pressure is controlled to be not less than 30KN / m. After film formation, the membrane is treated with plasma for hydrophilicity.

[0023] Example 2 Experimental Data Table

[0024]

[0025] Example 3

[0026] Diaphragm used for alkaline electrolytic hydrogen electrolyzer. Its main requirements are: low quantitative, high film strength, high temperature resistance, alkali resistance, good hydrophilicity, good air tightness, good durability, etc. 0.89D filament is used for beating in a beating machine, the concentration is 3%, and the beating degree of the pulp is controlled to be 55±3°SR for pulping. 0.89D*6mm PPS staple fiber is dispersed at a high speed of 3% for 10 minutes by a high-speed disperser for use. According to the total amount (net weight) of 60% staple fiber pulp + 40% staple fiber, the pulp is mixed into a dispersed slurry with a concentration of 0.4%. Add 0.025% (solid content) of the total amount of fiber pulp, add it to the pulp pool or add it continuously through the high-level box, and the diluted concentration is 0.4% PAM and PEO compound dispersant (PAM+PEO compounding: compounding process: 1gPEO is gradually added to 1000mL water while stirring, and it is dissolved and stirred for 40min, and then 3g PAM is gradually added and stirred and dissolved for 90min for use). The wet film embryo is formed by a circular or inclined net, and then dehydrated by vacuum suction and pressing, and then enters the drying cylinder group controlled at 90℃ for drying. After drying, the film is continuously hot-pressed at 210±10℃ and 260±10℃ to form a film embryo, and the hot pressing line pressure is controlled to be no less than 30KN / m. After forming the film, the film is treated with plasma for hydrophilicity.

[0027] Example 3 Experimental Data Table

[0028]

[0029] Example 4

[0030] Diaphragm used for alkaline electrolytic hydrogen electrolyzer. Its main requirements are: low quantitative, high film strength, high temperature resistance, alkali resistance, good hydrophilicity, good air tightness, good durability, etc. PPS pulp with an average diameter of 2μm is used for pulping in a trough beater, with a concentration of 2%, and the pulping time is controlled for 50min until the average length of the pulp fiber is cut less than about 2mm. 0.89D filament is used for pulping in a beater, with a concentration of 2%, and the pulping degree is controlled to be 55±3°SR for pulping. 0.89D*6mm PPS staple fibers are dispersed at a high speed of 3% for 10min in a high-speed disperser for use. According to the total amount (net weight), 40% pulp + 30% staple fiber pulp + 30% staple fiber are mixed to form a dispersed slurry with a concentration of 0.4%. Add 0.030% (solid content) of the total fiber pulp, add to the pulp pool or through the high-level box, and continuously add and dilute the concentration of 0.4% PAM and PEO compound dispersant (PAM+PEO compounding: compounding process: 1g PEO is gradually added to 1000mL water while stirring, and then 3g PAM is gradually added and stirred for 90 minutes for standby use). The wet film embryo is formed through a circular net or an inclined net, and is dehydrated by vacuum suction and pressing, and enters a drying cylinder group controlled at 80°C for drying. After drying, the film is continuously hot-pressed at 150±5°C, 210±10°C, and 260±10°C to form a film embryo, and the hot pressing line pressure is controlled to be not less than 25KN / m, 35KN / m, and 40KN / m respectively. After film formation, the membrane is treated with plasma for hydrophilicity.

[0031] Example 4 Experimental Data Table

[0032]

[0033] Table 5 is a table of experimental parameters for Examples 1-4

[0034]

[0035] In summary, the present invention uses multiple pulps and fibers to compositely form membranes, and the prepared membrane has a higher porosity and a lower pore size, so that the membrane has a lower resistance and a higher air tightness. The membrane after hot pressing has good mechanical strength and high burst resistance, and can adapt to the working environment of alkaline hydrogen electrolysis. The wet papermaking membrane making process is simple and has good industrial application prospects.

Claims

1. A method for producing an alkaline hydrogen electrolysis membrane, characterized in that: PPS fibers of different shapes are used for beating and dispersion respectively to obtain PPS fibers of different specifications; according to the requirements and usage of the electrolytic hydrogen diaphragm, various specifications of PPS fibers, PPS short fiber pulp and PPS pulp are added, and the PPS fibers, PPS short fiber pulp and PPS pulp are proportioned and dispersed according to the content, and auxiliary materials are added when mixing the slurry to play an auxiliary role in dispersion and wet bonding. After that, the formed wet film is obtained through a short papermaking process, and the wet film is vacuum and squeezed for dehydration, dried by a drying cylinder, and formed into a film by high temperature hot pressing, and then subjected to hydrophilic modification to form an alkaline electrolytic hydrogen diaphragm.

2. The method for producing an alkaline hydrogen electrolysis membrane according to claim 1, characterized in that: The PPS pulp uses PPS pulp with an average diameter of 2 μm, and is beaten in a trough beater at a concentration of 1% to 5%, and the beating time is controlled to be 40 to 60 minutes until the average length of the pulp fibers cut is less than about 2 mm.

3. The method for producing an alkaline hydrogen electrolysis membrane according to claim 2, characterized in that: PPS short fiber pulp is pulped with 0.89D filament in a pulping machine, with a concentration of 1% to 5%, and the beating degree is controlled to be 55±3°SR.

4. The method for producing an alkaline hydrogen electrolysis membrane according to claim 3, characterized in that: The PPS fiber is 0.89D*6mm short fiber or 3.2D*8mm PPS short fiber, or a composite of the two short fibers, and is dispersed at a high speed for 10 minutes at a concentration of 1% to 5% by a high-speed disperser.

5. The method for producing an alkaline hydrogen electrolysis membrane according to claim 4, characterized in that: The PPS pulp accounts for 30% to 70%, the PPS staple pulp accounts for 30% to 70%, and the PPS fiber accounts for 30% to 70%.

6. The method for producing an alkaline hydrogen electrolysis membrane according to claim 5, characterized in that: When preparing the pulp, the solid content of the dispersed pulp made of PPS fiber, PPS short fiber pulp and PPS pulp is 0.2% to 0.6%.

7. The method for producing an alkaline hydrogen electrolysis membrane according to claim 6, characterized in that: In the short papermaking process, the total solid content of the added PPS fibers, PPS staple fiber pulp and PPS pulp is 0.02% to 0.05%.

8. The method for producing an alkaline hydrogen electrolysis membrane according to claim 7, characterized in that: In the short papermaking process, the added dispersant is obtained by compounding PAM and PEO with a concentration of 0.4%.

9. The method for producing an alkaline hydrogen electrolysis membrane according to claim 7, characterized in that: The drying process of the drying cylinder controls the temperature at 80-95°C.

10. The method for producing an alkaline hydrogen electrolysis membrane according to claim 7, characterized in that: During the high temperature hot pressing film forming process, the embryonic membrane is hot pressed at a temperature of 150°C to 280°C to form a film, and the hot pressing line pressure is controlled to be not lower than 20 to 50 KN / m to form a film.

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