Preparation method of seawater desalination mixed matrix membrane, seawater desalination and hydrogen production integrated device and seawater desalination and hydrogen production method

Abstract

According to the preparation method of the seawater desalination mixed matrix membrane, the seawater desalination and hydrogen production integrated device and the seawater desalination and hydrogen production method, seawater is contained in the seawater desalination and hydrogen production integrated device, and gas (such as oxygen and hydrogen) generated in the seawater electrolysis process can improve the pressure in the device; and seawater is driven to penetrate through the mixed matrix membrane electrode, so that the purpose of seawater desalination is achieved. The mixed matrix membrane electrode utilizes a reverse osmosis method to press water molecules in seawater from one side of a mixed matrix membrane to the other side of the membrane, so that salt is removed to obtain clean water, and high-purity hydrogen is collected at the same time. The integrated device based on the mixed matrix membrane electrode prepared by the invention can efficiently remove salt in seawater and prepare high-purity hydrogen, and has a great application prospect.

Description

Technical Field

[0001] The present application belongs to the technical field of seawater desalination and hydrogen production, and in particular relates to a method for preparing a seawater desalination mixed matrix membrane, a seawater desalination and hydrogen production integrated device, and a seawater desalination and hydrogen production method. Background Art

[0002] Reverse osmosis (RO) is a membrane-based seawater desalination technology that applies a pressure greater than the osmotic pressure on one side of the seawater (raw water) to push the water molecules in the seawater (raw water) to the other side of the membrane, thereby removing salt and obtaining clean water.

[0003] In recent years, seawater desalination and electrolysis hydrogen production technology have received widespread attention. Hydrogen energy is considered to be one of the most ideal alternative clean energy sources to traditional fossil energy due to its high energy density and pollution-free characteristics. In particular, hydrogen energy can be obtained by electrolysis of water resources that exist in large quantities in nature. However, freshwater resources on land are extremely limited, so it is of great significance to use seawater for direct or indirect (first desalination) electrolysis to produce hydrogen. In the past few decades, people have designed and manufactured various forward / reverse osmosis membrane seawater desalination devices to improve the efficiency of seawater desalination and desalination.

[0004] The main methods for preparing polymer membranes are sintering, stretching, track etching, and phase inversion. Sintering is the simplest method for preparing porous membranes. It is to compact polymer powder particles and heat them evenly at high temperature to melt the powder particles but not completely melt them, so that certain pores are formed, so that a membrane can be prepared. The stretching method is suitable for some membrane materials that are solvent-free at room temperature. It is mainly used for the preparation of polyolefin flat membranes and hollow fiber membranes, which broadens the scope of use of membrane materials. Its principle is to stretch the film at room temperature, and slit-like pores will appear in the stretching direction, and then shape it at a higher temperature to obtain a symmetrical porous membrane. The track etching method is to expose the membrane material to vertical high-energy particle radiation, so that the polymer material is damaged to form an incomplete track. After that, the film is immersed in an etching agent to form pores. Its characteristic is that the formed pores are more evenly distributed. This method uses both physical and chemical effects to prepare the membrane. The phase inversion method refers to the preparation of a homogeneous polymer solution of a certain composition, and the use of certain physical methods to allow the solution to undergo mass transfer exchange between the solvent and the non-solvent in the surrounding environment, thereby changing the thermodynamic state of the solution, causing it to undergo phase separation from a homogeneous polymer solution and transform into a three-dimensional macromolecular network gel structure, which is eventually solidified into a film.

[0005] However, the water treatment polymer membranes prepared by the above methods are not suitable for direct use as membrane electrodes in seawater electrolysis devices due to their lack of conductivity. Current research shows that the membrane electrodes used in seawater desalination and electrolysis integrated devices must have excellent seawater desalination capacity, corrosion resistance, and electrocatalytic hydrogen / oxygen evolution capabilities at the same time, so that it is possible to achieve the integration of seawater desalination and electrolytic hydrogen production. Summary of the invention

[0006] 1. Problem to be solved

[0007] In view of the technical problems in the prior art that the efficiency of seawater desalination and electrolytic hydrogen production is low and it is difficult to achieve them simultaneously using devices and materials, a method for preparing a seawater desalination mixed matrix membrane, an integrated seawater desalination and hydrogen production device based on the seawater desalination mixed matrix membrane, and a seawater desalination and seawater electrolysis hydrogen production method based on the seawater desalination mixed matrix membrane are proposed.

[0008] 2. Technical solution

[0009] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0010] The present invention provides a method for preparing a mixed matrix membrane for seawater desalination, comprising the following steps:

[0011] Step 1: Dissolving polysulfone or polyethersulfone

[0012] Take a polymer material commonly used in seawater desalination reverse osmosis membranes such as polysulfone (PSU) or polyethersulfone (PESf) or triacetyl cellulose (TAC) or aromatic polyamide (APA), and an additive such as polyvinyl pyrrolidone (PVP) or polyethylene glycol (PEG), add them to a liquid organic solvent such as N-methylpyrrolidone (NMP) or N,N-dimethylformamide (DMF), and fully dissolve them to obtain, for example, a milky white polymer solution;

[0013] Step 2: Ball milling raw materials

[0014] Add powders of carbon materials (such as carbon fiber, graphite) or metals (such as nickel, titanium alloy) or conductive ceramics (such as titanium carbide) to the above polymer solution, mix by ball milling to obtain a uniform slurry, and remove bubbles in the slurry by vacuuming;

[0015] Step 3: Phase inversion casting

[0016] The slurry is scraped and coated into a film green body with controllable thickness by a cast coater, and then quickly transferred into water, taken out after standing for a period of time, and then dried to obtain a seawater desalination mixed matrix membrane.

[0017] Preferably, the specific steps of step 1 are:

[0018] Step 1-1, first add PSU, PESf, TAC, APA, etc. and PVP or PEG, etc. into NMP or DMF, and then ball-mill for 2-4 hours to obtain, for example, a milky white polymer solution.

[0019] Preferably, the specific steps of step 2 are:

[0020] After adding the carbon material, metal or conductive ceramic powder to the polymer solution, the mixture is ball-milled for 24-48 hours to obtain a uniformly mixed slurry, which is then vacuumed for 20-30 minutes to remove bubbles in the slurry.

[0021] Preferably, the specific steps of step 3 are:

[0022] The slurry after the bubbles are removed is placed on a cast coating machine, and the scraper height is adjusted to control the thickness of the cast green body. The casting speed is 10-100 cm / min, and then it is quickly transferred to a water tank with a water depth of 20-40 cm. After standing for 12-24 hours, it is taken out and then naturally dried at room temperature or dried at 100-200°C for 2-5 hours to obtain a seawater desalination mixed matrix membrane.

[0023] The invention discloses a seawater desalination mixed matrix membrane, wherein the membrane material is prepared by the above-mentioned preparation method.

[0024] The embodiment of the present invention provides a method for seawater desalination and seawater electrolysis hydrogen production based on seawater desalination mixed matrix membrane, the method comprising:

[0025] The oxygen evolution reaction at the anode during seawater electrolysis produces oxygen, and the hydrogen evolution reaction at the cathode produces hydrogen, so as to increase the pressure inside the device and drive seawater through the mixed matrix membrane electrode;

[0026] The seawater desalination mixed matrix membrane electrode uses reverse osmosis to press water molecules in seawater from one side of the mixed matrix membrane electrode to the other side of the membrane electrode, thereby removing salt to obtain clean water, and at the same time collecting high-purity hydrogen and oxygen.

[0027] The present invention discloses a seawater desalination and hydrogen production integrated device based on a mixed matrix membrane, which comprises: a seawater desalination and electrolysis reaction chamber and a mixed matrix membrane arranged on both sides of the reaction chamber, wherein a hydrogen (oxygen) evolution working electrode is installed inside the reaction chamber or the mixed matrix membrane can be directly used as a hydrogen (oxygen) evolution membrane electrode. A hydrogen (oxygen) evolution reaction occurs through the hydrogen (oxygen) evolution working (membrane) electrode, so that the pressure in the reaction chamber is increased to drive seawater to pass through the mixed matrix membrane, and pure water is obtained in the pure water chamber. The seawater desalination mixed matrix membrane is prepared by the preparation method of the seawater desalination mixed matrix membrane as described above.

[0028] 3. Beneficial effects

[0029] Compared with the prior art, the present invention has the following effects and advantages:

[0030] 1. The present invention provides a method for preparing a mixed matrix membrane for seawater desalination and a mixed matrix membrane material prepared therefrom, which is prepared by phase inversion casting and has abundant finger-like straight pores, which is beneficial to improving the permeation flux of pure water; the mixed matrix membrane prepared by the phase inversion casting method has an asymmetric membrane structure, wherein the porous layer side is beneficial to increasing the contact area between the membrane electrode and the electrolyte, and the dense layer side is beneficial to hindering the passage of anions and cations in seawater. In addition, the membrane preparation method has a wide range of applications, high production efficiency, and is easy to scale up for industrial production.

[0031] 2. The present invention provides a method for seawater desalination and seawater electrolysis hydrogen production based on seawater desalination mixed matrix membrane, which utilizes the hydrogen evolution reaction at the cathode to produce hydrogen and the oxygen evolution reaction at the anode to produce oxygen during the seawater electrolysis process to increase the pressure in the electrolysis device and drive seawater through the mixed matrix membrane electrode; the mixed matrix membrane electrode utilizes reverse osmosis to remove salt from seawater to obtain clean pure water. This method couples seawater desalination and seawater electrolysis hydrogen production, realizing the integration of seawater desalination and hydrogen production, and the total energy consumption of the system is lower than that of seawater desalination followed by electrolysis hydrogen production.

[0032] 3. The present invention provides an integrated desalination and hydrogen production device based on a desalination mixed matrix membrane. The electrolysis adopts direct seawater electrolysis without desalination treatment. Therefore, it breaks through the bottleneck of seawater desalination and hydrogen production restricted by time, climate, human activities and other factors, breaks through the bottleneck of traditional seawater desalination and hydrogen production technology, and does not need to build desalination plants and electrolysis plants on a large scale respectively, which greatly reduces the cost of construction, operation, manpower, maintenance and other aspects. At the same time, it can also be used for the desalination and electrolysis of high-salinity aqueous solutions such as salt lake water and industrial high-salinity water, which greatly broadens the source range of fresh water and hydrogen energy, and is not restricted by time and space. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 The overall principle diagram of the integrated device for seawater desalination and hydrogen production based on seawater desalination mixed matrix membrane provided by the present invention in Example 2;

[0034] Figure 2 The overall principle diagram of the integrated seawater desalination and hydrogen production device based on seawater desalination mixed matrix membrane provided by the present invention in Example 3;

[0035] Figure 3 The overall principle diagram of the integrated desalination and hydrogen production device based on the desalination mixed matrix membrane provided by the present invention in Example 4;

[0036] Figure 4 The overall principle diagram of the integrated seawater desalination and hydrogen production device based on seawater desalination mixed matrix membrane provided by the present invention in Example 5;

[0037] Figure 5 The overall principle diagram of the integrated desalination and hydrogen production device based on the desalination mixed matrix membrane provided by the present invention in Example 6;

[0038] The following are marked in the attached figure:

[0039] 2, 6, 13, 19, 22, 26 - seawater desalination mixed matrix membrane, 3, 9, 12, 16 - hydrogen or oxygen evolution working electrode, 4, 7, 10, 11, 15, 18, 23, 25 - seawater electrolysis reaction chamber, 1, 5, 14, 20, 21, 27 - pure water chamber, 8, 17, 24 - proton exchange membrane or anion exchange membrane. DETAILED DESCRIPTION

[0040] In order to further understand the content of the present invention, the present invention is described in detail with reference to the accompanying drawings and embodiments.

[0041] The structures, proportions, sizes, etc. drawn in the drawings of this specification are only used to match the contents disclosed in the specification for the understanding and reading of those familiar with this technology. They are not used to limit the limiting conditions for the implementation of the present invention, so they have no substantial technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size should still fall within the scope of the technical content disclosed by the present invention without affecting the effects and purposes that can be achieved by the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and so on quoted in this specification are only for the convenience of description, and are not used to limit the scope of implementation. The change or adjustment of their relative relationship should also be regarded as the scope of implementation of the present invention without substantial change of the technical content; in addition, the various embodiments of the present invention are not independent of each other, but can be combined.

[0042] The present invention provides a method for preparing a mixed matrix membrane for seawater desalination, and the preparation effect is as follows Figure 1 As shown, the steps include:

[0043] Step 1: Dissolving polysulfone or polyethersulfone

[0044] Take a polymer such as polysulfone, dissolve it in a liquid solvent, and obtain a polymer solution of milky white or other colors after it is fully dissolved; the specific steps are:

[0045] Polysulfone (PSU) or polyethersulfone (PESf) or triacetyl cellulose (TAC) or aromatic polyamide (APA) and other polymer materials used in common seawater desalination reverse osmosis membranes, as well as additives such as polyvinylpyrrolidone (PVP) or polyethylene glycol (PEG), are added to a liquid organic solvent such as N-methylpyrrolidone (NMP) or N,N-dimethylformamide (DMF), and ball-milled for 2-4 hours to fully dissolve them to obtain, for example, a milky white polymer solution.

[0046] Step 2: Ball milling slurry

[0047] Conductive carbon fiber powder is added to the above polymer solution, and then ball milled to obtain a uniformly mixed slurry, and bubbles in the slurry are removed; the specific steps are:

[0048] Take powders of carbon materials (such as carbon fiber, graphite) or metals (such as nickel, titanium alloy) or conductive ceramics (such as titanium carbide) and add them to the above polymer solution, mix them by ball milling for 24-48 hours to obtain a uniform slurry, and vacuum for 20-30 minutes to remove bubbles in the slurry.

[0049] Step 3: Phase inversion casting

[0050] The slurry is coated by a cast coating machine to form a green film with controllable thickness, and then quickly transferred into water, taken out after standing for a period of time, and then dried to obtain a seawater desalination mixed matrix membrane; the specific steps are:

[0051] The slurry after removing bubbles is placed on a cast coating machine at a casting speed of 10-100 cm / min, and then quickly transferred to a water tank with a water depth of 20-40 cm, left to stand for 12-24 hours, and then dried naturally at room temperature or dried at 100-200°C for 2-5 hours to obtain a seawater desalination mixed matrix membrane.

[0052] After the seawater desalination mixed matrix membrane of the present invention is prepared, it is used in a seawater desalination and hydrogen production integrated device based on the seawater desalination mixed matrix membrane of the present invention, such as Figure 2 As shown, it includes a seawater electrolysis reaction chamber, a seawater desalination mixed matrix membrane, a pure water chamber, and a gas chamber.

[0053] Example 1

[0054] The preparation method of a mixed matrix membrane for seawater desalination in this embodiment is being implemented, and the specific process is as follows:

[0055] Take polysulfone (PSU) or polyethersulfone (PESf) or triacetyl cellulose (TAC) or aromatic polyamide (APA), etc., and additives such as polyvinyl pyrrolidone (PVP) or polyethylene glycol (PEG), etc., add PSU or PESf or TAC or APA, etc. and PVP or PEG, etc. into N-methylpyrrolidone (NMP) or N,N-dimethylformamide (DMF), and fully dissolve PSU or PESf or TAC or APA, etc. to obtain, for example, a milky white polymer solution;

[0056] In order to make the carbon fiber powder or metal titanium powder or titanium carbide ceramic powder uniformly distributed in the polymer solution, commercially used 200 mesh or other mesh powders are added to the above polymer solution, ball milled for 48 hours to obtain a uniformly mixed slurry, and vacuumed for 20 minutes to remove bubbles in the slurry;

[0057] The slurry after removing bubbles was placed on a cast coater at a casting speed of 20 cm / min, and then the cast green body was quickly transferred to a water tank with a water depth of 40 cm, left to stand for 12 hours, and dried at 200°C for 2 hours to obtain a seawater desalination mixed matrix membrane.

[0058] In this embodiment, the prepared seawater desalination mixed matrix membrane is applied to the above-mentioned seawater desalination and hydrogen production integrated device.

[0059] Example 2

[0060] In this embodiment, a desalination and hydrogen production integrated device is specifically provided. When the device is used, the reaction chamber is filled with various high-salt aqueous solutions such as seawater, salt lake water, and industrial high-salt water. The hydrogen and oxygen generated by electrolysis drive the seawater through the desalination mixed matrix membrane to complete the desalination process, and the hydrogen and oxygen are collected in the gas chamber.

[0061] like Figure 1 As shown, the integrated desalination and hydrogen production device comprises: a seawater electrolysis reaction chamber 4 and a seawater desalination mixed matrix membrane 2 arranged on the left side of the seawater electrolysis reaction chamber 4, and a hydrogen evolution reaction working electrode 3 is installed inside the seawater electrolysis reaction chamber 4. Hydrogen is generated by the hydrogen evolution reaction working electrode 3 and oxygen is generated by the oxygen evolution mixed matrix membrane electrode 2, so that the pressure of the seawater electrolysis reaction chamber 4 increases to drive the seawater to pass through the seawater desalination mixed matrix membrane 2, and pure water is obtained in the pure water chamber 1.

[0062] Based on the above-mentioned integrated desalination and hydrogen production device, its working principle is as follows:

[0063] First, the energy source of the device can be electric energy converted from renewable energy such as solar energy and wind energy. The seawater in the seawater electrolysis reaction chamber 4 undergoes a hydrogen evolution reaction on the surface of the hydrogen evolution working electrode 3 to produce hydrogen. The reaction formula is as follows:

[0064] 2H + +2e - →H 2 or 2H 2 O+2e - →2OH - +H 2

[0065] Oxygen evolution reaction occurs on the seawater desalination mixed matrix membrane electrode 2 on the left side of the seawater electrolysis reaction chamber 4 to produce oxygen, and the reaction formula is as follows:

[0066] 2H 2 O-4e - →O 2 +4H + or 4OH - -4e - →O 2 +2H 2 O

[0067] The generated hydrogen and oxygen are accumulated in the seawater electrolysis reaction chamber 4, so that the pressure increases and drives the seawater to be desalinated to pass through the seawater desalination mixed matrix membrane 2, completing the desalination process. In the above, the available hydrogen evolution working electrode 3 includes but is not limited to: platinum sheet, modified Raney nickel, platinum-plated nickel mesh, corrosion-resistant Pt, Pd noble metals and their alloys, etc.; the available seawater desalination mixed matrix membrane 2 includes but is not limited to: polymer-based mixed matrix membranes such as polyphenylene sulfide (PPS) or PSU or PESf or TAC or APA.

[0068] Example 3

[0069] like Figure 2 As shown, the integrated seawater desalination and hydrogen production device includes: a seawater electrolysis reaction chamber is separated by a proton exchange membrane (or anion exchange membrane) 8 into a seawater electrolysis reaction chamber 7 and a seawater electrolysis reaction chamber 10, and a hydrogen evolution working electrode 9 located in the seawater electrolysis reaction chamber 10, a seawater desalination mixed matrix membrane electrode 6 for oxygen evolution reaction, and a pure water chamber 5.

[0070] Based on the above-mentioned integrated desalination and hydrogen production device, its working principle is as follows:

[0071] First, the energy source of the device can be electric energy converted from renewable energy such as solar energy and wind energy. The seawater in the seawater electrolysis reaction chamber 10 undergoes a hydrogen evolution reaction on the surface of the hydrogen evolution working electrode 9 to produce hydrogen. The reaction formula is as follows:

[0072] 2H + +2e - →H 2 or 2H 2 O+2e - →2OH - +H 2

[0073] Water molecules or OH in the seawater electrolysis reaction chamber 7 - Oxygen evolution reaction occurs on the seawater desalination mixed matrix membrane electrode 6 to generate oxygen and store it in the upper end of the seawater electrolysis reaction chamber 7. The reaction formula is as follows:

[0074] 2H 2 O-4e - →O 2 +4H + or 4OH- -4e - →O 2 +2H 2 O

[0075] The oxygen partial pressure in the seawater electrolysis reaction chamber 7 increases and drives the seawater in the seawater electrolysis reaction chamber 7 to pass through the seawater desalination mixed matrix membrane electrode 6, and obtains clean pure water in the pure water chamber 5. In the above, the available hydrogen evolution working electrode 9 includes but is not limited to: platinum sheet, modified Raney nickel, platinum-plated nickel mesh, corrosion-resistant Pt, Pd precious metals and their alloys, etc.; the available seawater desalination mixed matrix membrane electrode 6 includes but is not limited to: polymer-based mixed matrix membranes such as PPS or PSU or PESf or TAC or APA.

[0076] Example 4

[0077] like Figure 3 As shown, the integrated desalination and hydrogen production device includes: a seawater electrolysis reaction chamber 11 and a seawater desalination mixed matrix membrane electrode 13 and a pure water chamber 14 arranged on the right side of the reaction chamber. The seawater electrolysis reaction chamber 11 is equipped with an oxygen evolution working electrode 12.

[0078] Based on the above-mentioned integrated desalination and hydrogen production device, its working principle is as follows:

[0079] First, the energy source of the device can be electric energy converted from renewable energy such as solar energy and wind energy. The seawater in the seawater electrolysis reaction chamber 11 undergoes hydrogen evolution reaction on the surface of the seawater desalination mixed matrix membrane electrode 13 to produce hydrogen. The reaction formula is as follows:

[0080] 2H + +2e - →H 2 or 2H 2 O+2e - →2OH - +H 2

[0081] Water molecules or OH in seawater - An oxygen evolution reaction occurs on the oxygen evolution working electrode 12 in the seawater electrolysis reaction chamber 11 to produce oxygen, and the reaction formula is as follows:

[0082] 2H 2 O-4e - →O 2 +4H + or 4OH - -4e - →O 2 +2H 2 O

[0083] The generated hydrogen and oxygen are accumulated in the seawater electrolysis reaction chamber 11, so that the pressure increases and drives the seawater to be desalinated to pass through the seawater desalination mixed matrix membrane electrode 13 to complete the desalination process. Among the above, the available oxygen evolution working electrode 12 includes but is not limited to: RuO 2 、IrO 2 Other precious metal oxides, AB 2 O 4 Spinel oxides and ABO 3 Perovskite oxide materials; available hydrogen evolution-seawater desalination mixed matrix membrane electrode 13 includes but is not limited to: polymer-based mixed matrix membranes such as PPS or PSU or PESf or TAC or APA.

[0084] Example 5

[0085] like Figure 4 As shown, the integrated seawater desalination and hydrogen production device includes: a seawater electrolysis reaction chamber is separated into a seawater electrolysis reaction chamber 15 and a seawater electrolysis reaction chamber 18 by a proton exchange membrane (or anion exchange membrane) 17, the seawater electrolysis reaction chamber 15 is equipped with an oxygen evolution working electrode 16, and the right side of the seawater electrolysis reaction chamber 18 is a seawater desalination mixed matrix membrane electrode 19 and a pure water chamber 20.

[0086] Based on the above-mentioned integrated desalination and hydrogen production device, its working principle is as follows:

[0087] First, the energy source of the device can be electric energy converted from renewable energy such as solar energy and wind energy. The seawater in the seawater electrolysis reaction chamber 18 undergoes hydrogen evolution reaction on the surface of the seawater desalination mixed matrix membrane electrode 19 to produce hydrogen. The reaction formula is as follows:

[0088] 2H + +2e - →H 2 or 2H 2 O+2e - →2OH - +H 2

[0089] Water molecules or OH in the seawater electrolysis reaction chamber 15 - Oxygen evolution reaction occurs on the oxygen evolution working electrode to generate oxygen and store it at the upper end of the seawater electrolysis reaction chamber 15. The reaction formula is as follows:

[0090] 2H 2 O-4e - →O 2 +4H + or 4OH - -4e - →O 2 +2H 2 O

[0091] The generated hydrogen accumulates in the seawater electrolysis reaction chamber 18, causing the pressure to increase to drive the seawater to be desalinated to pass through the seawater desalination mixed matrix membrane electrode 19, completing the desalination process. Among the above, the available oxygen evolution working electrode 16 includes but is not limited to: RuO 2 、IrO 2 Other precious metal oxides, AB 2 O 4 Spinel oxides and ABO 3 Perovskite oxide materials; available hydrogen evolution-seawater desalination mixed matrix membrane electrode 19 includes but is not limited to: polymer-based mixed matrix membranes such as PPS or PSU or PESf or TAC or APA.

[0092] Example 6

[0093] like Figure 5 As shown, the integrated seawater desalination and hydrogen production device includes: a seawater electrolysis reaction chamber is separated into a seawater electrolysis reaction chamber 23 and a seawater electrolysis reaction chamber 25 by a proton exchange membrane (or anion exchange membrane) 24, and the left side of the seawater electrolysis reaction chamber 23 and the right side of the reaction chamber 25 are respectively an oxygen evolution-seawater desalination mixed matrix membrane electrode 22 and a hydrogen evolution-seawater desalination mixed matrix membrane electrode 26. The seawater desalinated by the seawater desalination mixed matrix membranes 22 and 26 finally reaches the pure water chamber 21 and the pure water chamber 27 respectively.

[0094] Based on the above-mentioned integrated desalination and hydrogen production device, its working principle is as follows:

[0095] First, the energy source of the device can be electric energy converted from renewable energy such as solar energy and wind energy. The seawater in the seawater electrolysis reaction chamber 25 undergoes hydrogen evolution reaction on the surface of the hydrogen evolution-seawater desalination mixed matrix membrane electrode 26 to produce hydrogen. The reaction formula is as follows:

[0096] 2H + +2e - →H 2 or 2H 2 O+2e - →2OH - +H 2

[0097] The generated hydrogen accumulates in the seawater electrolysis reaction chamber 25 so that the pressure increases to drive the seawater to be desalinated to pass through the seawater desalination mixed matrix membrane electrode 26, complete the desalination and collect pure water in the pure water chamber 27.

[0098] The seawater in the seawater electrolysis reaction chamber 23 undergoes an oxygen evolution reaction on the surface of the seawater desalination mixed matrix membrane electrode 22 to produce oxygen. The reaction formula is as follows:

[0099] 2H 2 O-4e- →O 2 +4H + or 4OH - -4e - →O 2 +2H 2 O

[0100] The generated oxygen accumulates in the seawater electrolysis reaction chamber 23 so that the pressure increases to drive the seawater to be desalinated to pass through the seawater desalination mixed matrix membrane electrode 22, completing the desalination process and collecting pure water in the pure water chamber 21.

[0101] Among the above, the available mixed matrix membranes for seawater desalination include but are not limited to: polymer-based mixed matrix membranes such as PPS or PSU or PESf or TAC or APA.

[0102] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention (including the claims) is limited to these examples. Under the concept of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0103] The embodiments of the present invention are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a mixed matrix membrane for seawater desalination, characterized in that the steps include: Step 1: Dissolving polysulfone or polyethersulfone Take a polymer material polysulfone PSU or polyethersulfone PESf or triacetyl cellulose TAC or aromatic polyamide APA, and an additive polyvinyl pyrrolidone PVP or polyethylene glycol PEG, add them into a liquid organic solvent N-methylpyrrolidone NMP or N,N-dimethylformamide DMF, and dissolve them to obtain, for example, a milky white polymer solution; Step 2: Ball milling slurry Add carbon material powder or metal powder or conductive ceramic powder to the above polymer solution, mix by ball milling to obtain slurry, and remove air bubbles in the slurry by vacuuming; Step 3: Phase inversion casting The slurry is scraped and coated into a film green body with controllable thickness by a cast coater, and then transferred into water, taken out after standing for a preset time, and then dried to obtain a seawater desalination mixed matrix membrane.

2. The method for preparing a mixed matrix membrane for seawater desalination according to claim 1, characterized in that: The specific steps of step 1 are: Step 1-1, add polysulfone PSU or polyethersulfone PESf or cellulose triacetate TAC or aromatic polyamide APA and polyvinylpyrrolidone PVP or polyethylene glycol PEG to N-methylpyrrolidone NMP or N,N-dimethylformamide DMF, and obtain, for example, a milky white polymer solution after ball milling for 2-4 hours.

3. The method for preparing a mixed matrix membrane for seawater desalination according to claim 1, characterized in that: The specific steps of step 2 are: after adding the carbon material powder or metal powder or conductive ceramic powder into the polymer solution, ball milling is performed for 24-48 hours to obtain a uniformly mixed slurry, and then vacuuming is performed for 20-30 minutes to remove bubbles in the slurry.

4. The method for preparing a mixed matrix membrane for seawater desalination according to claim 1, characterized in that: The specific steps of step 3 are: placing the slurry after removing bubbles on a cast coating machine, and adjusting the scraper height to control the thickness of the cast green body, the casting speed is 10-100 cm / min, and then transferring it to a water tank with a water depth of 20-40 cm, taking it out after standing for 12-24 hours, and drying it naturally at room temperature or drying it at 100-200°C for 2-5 hours to obtain a seawater desalination mixed matrix membrane.

5. A method for seawater desalination and seawater electrolysis hydrogen production based on seawater desalination mixed matrix membrane, characterized in that: The method includes: The oxygen evolution reaction at the anode during seawater electrolysis produces oxygen, and the hydrogen evolution reaction at the cathode produces hydrogen, so as to increase the pressure in the electrolysis device and drive the seawater through the mixed matrix membrane electrode; The seawater desalination mixed matrix membrane electrode uses reverse osmosis to press water molecules in seawater from one side of the mixed matrix membrane electrode to the other side of the membrane electrode, thereby removing salt to obtain clean water, and at the same time collecting high-purity hydrogen and oxygen.

6. A seawater desalination and hydrogen production integrated device based on seawater desalination mixed matrix membrane, characterized in that: The device uses the seawater desalination mixed matrix membrane prepared by the preparation method of the seawater desalination mixed matrix membrane according to any one of claims 1 to 4 and is used to implement the seawater desalination and seawater electrolysis hydrogen production integrated method based on the seawater desalination mixed matrix membrane according to claim 5, and the device comprises: A seawater electrolysis reaction chamber, wherein the seawater electrolysis reaction chamber is filled with seawater to be electrolyzed; A seawater desalination mixed matrix membrane is arranged on the side of the seawater electrolysis reaction chamber, and the seawater electrolysis reaction chamber is connected to the pure water chamber through the mixed matrix membrane. The hydrogen and oxygen generated by electrolysis drive the seawater to pass through the mixed matrix membrane to obtain clean pure water through the reverse osmosis process, and hydrogen and oxygen are obtained at the cathode and anode at the same time; Anion and cation exchange membranes are installed in the seawater electrolysis reaction chamber to isolate the hydrogen and oxygen produced by electrolysis while allowing OH - Or protons pass through, accelerating the redox reaction of OH- or protons on the electrode.

7. The integrated desalination and hydrogen production device based on seawater desalination mixed matrix membrane according to claim 6, characterized in that: The desalination mixed matrix membrane is an asymmetric polymer-based mixed matrix conductive membrane prepared by a phase inversion casting method, including any one of Ti-PSU, TiC-TAC, graphite-PESf and carbon fiber-APA composite materials composed of polymer materials and metals, ceramics or carbon materials in pairs.

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