System for directly electrolyzing hydrogen from non-pure water by using immersed energy-consumption-free mass transfer device

Abstract

The utility model relates to a system for directly electrolyzing hydrogen from non-pure water by using an immersed energy-consumption-free mass transfer device. The system comprises an energy supply module, an electrolytic hydrogen production module and an immersed electrolyte cyclic regeneration module, and the energy supply module is connected with the electrolytic hydrogen production module; an electrolytic hydrogen production module; and the immersed electrolyte cyclic regeneration module is connected with the electrolytic hydrogen production module. According to the system, the direct electrolysis hydrogen production process of the non-pure water solution can be achieved, the electrolysis energy consumption is equivalent to the energy consumption of industrial electrolysis purified water, and extra desalination / purification energy consumption is not needed.

Description

Technical Field

[0001] The utility model belongs to the technical field of electrolytic hydrogen production, in particular to a system for directly electrolyzing non-pure water to produce hydrogen by utilizing an immersed energy-free mass transfer device. Background Art

[0002] Hydrogen energy has the advantages of wide sources, storability, multiple uses, zero carbon and zero pollution, and high energy density, and is a key component of the future energy field. Currently, there are two ways to obtain hydrogen energy by electrolyzing water. One is to use natural seawater, river water or lake water to directly electrolyze hydrogen, which has the following problems:

[0003] (1) The composition is complex and varies with factors such as season, climate, temperature, region and human activities. Therefore, non-pure water direct hydrogen production electrolysis devices in different regions are not directly compatible;

[0004] (2) The solution is rich in Cl - In the electrolysis reaction, Cl - Can be oxidized in the oxygen evolution reaction to produce ClO which is toxic, environmentally harmful and corrosive - and Cl2;

[0005] (3) When direct hydrogen production from non-pure aqueous solution is carried out, H + and OH - The ion concentration is too small or the buffer molecules cannot transport OH at the cathode and anode. - and H + , resulting in low electrolysis efficiency, so additional additives or ion exchange membranes are needed, which greatly increases costs;

[0006] (4) Complex components such as impure ions, microorganisms, and organic matter in non-pure aqueous solutions can easily clog and contaminate ion exchange membranes, or even cause membrane inactivation, thereby significantly increasing subsequent maintenance costs;

[0007] (4) Due to the local pH difference during electrolysis, precipitation may occur with calcium and magnesium ions, and acid precipitation treatment is required, which incurs additional costs.

[0008] The second is to desalinate / purify the non-pure water solution to produce pure water for electrolysis to produce hydrogen. Taking seawater as an example, it needs to go through the desalination process. This method requires the establishment of a desalination plant on the coast, which greatly increases the cost in terms of construction, operation, manpower, and maintenance. It is also difficult to use offshore wind power coupling on a large scale to form an in-situ integrated green hydrogen production system to achieve stable storage of renewable energy. Utility Model Content

[0009] The object of the present utility model is to provide a system for directly electrolyzing non-pure water to produce hydrogen by using an immersion-type energy-free mass transfer device in view of the problems existing in the prior art. This system can directly obtain pure water from various non-pure waters such as seawater, river water, lake water, industrial wastewater, and domestic sewage through an electrolyte for hydrogen production. The present utility model can fundamentally solve problems such as the failure of ion exchange membranes, the inactivation of catalysts, the generation of precipitates and toxic gases due to complex ion components; save the equipment investment and desalination / purification costs of desalination / purification plants; at the same time, it helps the future hydrogen energy conversion to be unrestricted by time and space, providing strong technical support for the direct hydrogen production from non-pure aqueous solutions.

[0010] In order to achieve the above object of the utility model, the specific technical solution of the present utility model is as follows:

[0011] A system for directly electrolyzing non-pure water to produce hydrogen by using an immersion-type energy-free mass transfer device, which is a system for directly electrolyzing non-pure aqueous solutions to produce hydrogen. The system includes an energy supply module, an electrolytic hydrogen production module, and an immersion-type electrolyte circulation and regeneration module, wherein:

[0012] The energy supply module is connected to the electrolytic hydrogen production module; it is used to provide electrical energy for the hydrogen production reaction;

[0013] The electrolytic hydrogen production module includes an electrolytic cell. After the electrolyte is introduced into the electrolytic cell, an oxidation-reduction reaction occurs, consuming water and generating hydrogen and oxygen;

[0014] The immersion-type electrolyte circulation and regeneration module is connected to the electrolytic hydrogen production module; it is used to directly supplement pure water to the electrolyte from non-pure aqueous solutions; the immersion-type electrolyte circulation and regeneration module includes an immersion-type energy-free mass transfer device.

[0015] Furthermore, the energy source of the energy supply module is electrical energy converted from traditional coal power or renewable energy.

[0016] Furthermore, after the electrolytic hydrogen production module completes the electrolytic hydrogen production work, the electrolytic cell is any one of an alkaline electrolytic cell (AWE), a (proton exchange membrane) PEM electrolytic cell, an (anion exchange membrane) AEM electrolytic cell, or a combination formed by connecting any electrolytic cell in series or in parallel. The electrolyte filled in the electrolytic cell is a liquid electrolyte or a solid gel electrolyte; wherein the liquid electrolyte is a liquid with a low saturated vapor pressure or a liquid with the function of absorbing water vapor; wherein the solid electrolyte is a substance that induces the phase change and liquefaction of water vapor.

[0017] Furthermore, the immersion type energy-free mass transfer device is a hollow device including a waterproof and breathable layer (for example, a waterproof and breathable layer is provided on any one side (partial or all) of the outer surface of the cavity, and the remaining surfaces are made of waterproof and corrosion-resistant materials; the electrolyte is pumped in through the opened holes in advance and then the holes are sealed; the waterproof and breathable layer can also be provided on any two sides, any three sides, any four sides, any five sides of the outer surface of the hollow cavity device; the immersion type energy-free mass transfer device can also be a three-dimensional cavity with all six sides composed of waterproof and breathable layers; when the immersion type energy-free mass transfer device is an irregular hollow cavity, all its surfaces can be composed of waterproof and breathable layers).

[0018] The immersion type energy-free mass transfer device with a waterproof and breathable layer is placed in a non-pure aqueous solution. The waterproof and breathable layer isolates the electrolyte in the cavity of the immersion type energy-free mass transfer device, preventing the electrolyte and the non-pure aqueous solution from penetrating each other; it is a module for realizing the "liquid-gas-liquid" phase change migration process, and this module uses the non-pure aqueous solution to directly supplement pure water into the relatively high-concentration electrolyte solution. The immersion type energy-free mass transfer device is a device capable of realizing the "liquid-gas-liquid" phase change migration process; when the immersion type energy-free mass transfer device is immersed in the non-pure aqueous solution, the interfacial vapor pressure difference between the non-pure aqueous solution and the electrolyte in the immersion type energy-free mass transfer device causes the non-pure aqueous solution to undergo phase change gasification (the saturated vapor pressure of the electrolyte is lower than that of the non-pure aqueous solution), and the generated water vapor enters the immersion type energy-free mass transfer device through the waterproof and breathable layer, and under the action of the interfacial vapor pressure difference, the water vapor is induced to liquefy and undergo a secondary phase change, realizing the process of "liquid-gas-liquid" phase change migration; in addition, the waterproof and breathable layer blocks the impurities in the non-pure aqueous solution outside and prevents the mutual penetration and pollution of the electrolyte and the non-pure aqueous solution.

[0019] The non-pure aqueous solution described above is selected from seawater, river water, lake water, wastewater or domestic sewage.

[0020] Furthermore, the waterproof and breathable layer in the immersion type energy-free mass transfer device is a commercially mature waterproof and breathable layer, or is selected from any one of porous TPU membranes, PDMS, and PTFE membranes, or a porous waterproof and breathable mass transfer layer prepared from graphene, PVDF particles, and PTFE particles by spraying, screen printing or electrospinning processes. More preferably, the electrolytic hydrogen production module includes an electrolytic cell and an electrolyte temperature controller; the electrolytic cell and the electrolyte temperature controller are connected.

[0021] More preferably, the immersion type electrolyte circulation and regeneration module includes an immersion type energy-free mass transfer device, a heat exchanger, a filter, an electrolyte circulation pump, and an electrolyte check valve; both the anode and the cathode of the electrolytic cell are connected to the heat exchanger, and after the heat exchanger is connected to the filter, it is connected to the immersion type energy-free mass transfer device; the immersion type energy-free mass transfer device is connected to the electrolyte temperature controller of the electrolytic hydrogen production module through the electrolyte circulation pump and the electrolyte check valve.

[0022] Furthermore, for the electrolytic hydrogen production system without pure water, the system further includes a hydrogen collection module and an oxygen collection module; wherein the hydrogen collection module includes a hydrogen separator, a hydrogen scrubber, a hydrogen cooler, and a hydrogen storage tank; the oxygen collection module includes an oxygen separator, an oxygen scrubber, an oxygen cooler, and an oxygen storage tank; both the hydrogen separator and the oxygen separator are respectively connected to the electrolytic cell, and a hydrogen scrubber, a hydrogen cooler, and a hydrogen storage tank are sequentially connected after the hydrogen separator; an oxygen scrubber, an oxygen cooler, and an oxygen storage tank are sequentially connected after the oxygen separator. It is used to separate the electrolyte / water entrained in hydrogen and oxygen, and at the same time wash, dry, and store the collected gas.

[0023] More preferably, a hydrogen regulating valve and a check valve are provided between the hydrogen scrubber and the hydrogen cooler; an oxygen regulating valve and a check valve are provided between the oxygen scrubber and the oxygen cooler.

[0024] Furthermore, the non-pure aqueous solution electrolytic hydrogen production system further includes a cooling module, and the cooling module includes a radiator, a cooling water tank, and a cooling water pump; the cooling water tank is connected to the radiator and is connected to the hydrogen separator, the hydrogen scrubber, the hydrogen cooler, the oxygen separator, the oxygen scrubber, the oxygen cooler, and the heat exchanger through the cooling water pump for providing cooling water.

[0025] Furthermore, the electrolyte pumped out from the electrolytic cell, as well as the electrolytes collected in the hydrogen separator, the oxygen separator, the hydrogen scrubber, and the oxygen scrubber, enter the immersion type energy-free mass transfer device after passing through the heat exchanger and the filter.

[0026] Furthermore, each module in the system is connected to the control system for automatic control of the process.

[0027] In this application, the immersion type energy-free mass transfer device is the most important part of the whole system and is also the key component that differentiates from the traditional electrolytic hydrogen production system process. The immersion type energy-free mass transfer device is a device including a waterproof and breathable layer. The waterproof and breathable layer isolates the electrolyte in the cavity of the immersion type energy-free mass transfer device, preventing the electrolyte from mutually penetrating with the non-pure aqueous solution. When the immersion type energy-free mass transfer device is immersed in the non-pure aqueous solution, the interfacial vapor pressure difference between the non-pure aqueous solution and the electrolyte causes the non-pure aqueous solution to undergo phase change gasification. The generated water vapor enters the electrolyte side through the waterproof and breathable layer and is induced to liquefy to undergo a secondary phase change under the action of the interfacial vapor pressure difference. It is a process of "liquid-gas-liquid" phase change migration and is a continuous process of directly using the non-pure aqueous solution to supplement pure water into the relatively high-concentration electrolyte. In addition, the waterproof and breathable layer effectively blocks the impurities in the non-pure aqueous solution and prevents the mutual penetration and pollution of the electrolyte and the non-pure aqueous solution. This process continuously supplements pure water to the electrolyte for electrolysis use. During electrolysis, water is consumed to maintain the interfacial vapor pressure difference between the electrolyte and the non-pure aqueous solution in the immersion type energy-free mass transfer device, thereby inducing the continuous replenishment of water into the electrolyte.

[0028] Preferably, the waterproof and breathable layer in the self-made immersion type energy-free mass transfer device is preferably any one of a commercially mature waterproof and breathable layer, a porous TPU film, PDMS, and a PTFE film, or a porous waterproof and breathable mass transfer layer prepared by spraying, screen printing, or electrospinning processes using graphene, PVDF particles, and PTFE particles.

[0029] Preferably, the electrolyte filled in the electrolytic cell and the immersion type energy-free mass transfer device is a liquid electrolyte or a solid gel electrolyte; wherein the liquid electrolyte is a liquid with a relatively low saturated water vapor pressure or a liquid with the function of absorbing water vapor, including alkaline liquid electrolytes, acidic liquid electrolytes, and ionic liquids; the alkaline liquid electrolytes are selected from one of KOH solution, K2CO3 solution, KHCO3 solution, NaOH solution, Na2CO3 solution, NaHCO3 solution, K3PO4 solution, CH3COOK solution, Ca(OH)2 and other alkaline substances, or a combination thereof. The acidic liquid electrolytes are, for example, one of H2SO4 solution, H3PO4 solution and other acidic substances, or a combination thereof. The ionic liquids are, for example, 1-ethyl-3-methylimidazolium acetate, etc. The organic hygroscopic liquid is PEG, etc. The solid electrolyte is a substance that can induce the phase change liquefaction of water vapor. The solid gel electrolyte is, for example, polyacrylamide hydrogel, poly(sulfonic acid group acrylamide) hydrogel, poly(methacrylamide) hydrogel, poly(benzyl acrylamide) hydrogel, poly(phenyl acrylamide) hydrogel, poly(ethyl acrylamide) hydrogel, poly(tert-butyl acrylamide) hydrogel, etc., and is one of all hygroscopic gels with hydrophilic groups such as hydroxyl group, sulfonic acid group, carboxyl group, amino group, and ether group, or a combination thereof.

[0030] Preferably, all components in the system device are connected to the control system for automating the system process.

[0031] Preferably, the energy source of the energy supply module can be traditional coal power or electric energy converted from renewable energy such as solar energy and wind energy.

[0032] A system for directly electrolyzing non-pure water to produce hydrogen using an immersion type energy-free mass transfer device, wherein the immersion type energy-free mass transfer device is a device including a waterproof and breathable layer; specifically, the immersion type energy-free mass transfer device is a container with a waterproof and breathable layer on any one or more sides and filled with electrolyte inside. The specific structure of the system is as follows: it includes an energy supply module, an electrolytic cell, a hydrogen separator, a hydrogen scrubber, a hydrogen regulating valve, a hydrogen check valve, a hydrogen cooler, a hydrogen storage tank, an oxygen separator, an oxygen scrubber, an oxygen regulating valve, an oxygen check valve, an oxygen cooler, an oxygen storage tank, a radiator, a cooling water tank, a cooling water pump, a heat exchanger, a filter, an immersion type energy-free mass transfer device, an electrolyte circulation pump, an electrolyte check valve, and an electrolyte thermostat; among them, the immersion type energy-free mass transfer device is a device capable of realizing the "liquid-gas-liquid" phase change migration process. When the immersion type energy-free mass transfer device is immersed in a non-pure aqueous solution, the non-pure aqueous solution spontaneously supplements pure water to the electrolyte in the immersion type energy-free mass transfer device; the energy supply module is connected to the cathode and anode of the electrolytic cell to provide electric energy; a hydrogen separator is arranged on the cathode side of the electrolytic cell, and a hydrogen scrubber, a hydrogen regulating valve, a hydrogen check valve, a hydrogen cooler, and a hydrogen storage tank are sequentially arranged behind the hydrogen separator; an oxygen separator is arranged on the anode side of the electrolytic cell, and an oxygen scrubber, an oxygen regulating valve, an oxygen check valve, an oxygen cooler, and an oxygen storage tank are sequentially arranged behind the oxygen separator; the electrolytic cell, the hydrogen separator, and the oxygen separator are all connected to the heat exchanger, and the heat exchanger is connected to the filter and then communicated with the immersion type energy-free mass transfer device; the immersion type energy-free mass transfer device is connected to the electrolyte thermostat through the electrolyte circulation pump and the electrolyte check valve, and the electrolyte thermostat is connected to the electrolytic cell; the cooling water tank is connected to the hydrogen separator, the hydrogen scrubber, the hydrogen cooler, the oxygen separator, the oxygen scrubber, the oxygen cooler, and the heat exchanger respectively through the cooling water pump.

[0033] Using the system for directly electrolyzing non-pure water to produce hydrogen with the described immersion type energy-free mass transfer device to perform the electrolytic hydrogen production process without pure water, which includes the following steps:

[0034] First, the electrolyte is introduced into the cathode of the electrolytic cell, or the anode, or both the cathode and anode simultaneously, and an oxidation-reduction reaction occurs to generate hydrogen and oxygen.

[0035] If the electrolytic cell is an alkaline electrolytic cell or an AEM electrolytic cell, the electrolyte first undergoes a reduction hydrogen evolution reaction at the cathode, generating OH -The electrolyte enters the anode through the diaphragm or anion exchange membrane and undergoes an oxidation reaction to produce oxygen. If the electrolyzer is a PEM electrolyzer, the electrolyte first undergoes an oxidation reaction at the anode to produce H + Enter the cathode through the proton exchange membrane and undergo a reduction reaction to produce hydrogen;

[0036] The generated hydrogen and oxygen enter the hydrogen separator and oxygen separator respectively, and this process separates the generated hydrogen and oxygen from the mixed electrolyte or water; the separated hydrogen and oxygen enter the hydrogen scrubber and oxygen scrubber respectively, and this process further fully cleans the electrolyte and water that are not separated cleanly in the gas; the cleaned hydrogen enters the hydrogen cooler under the control of the hydrogen regulating valve and the check valve to dry and cool the hydrogen, and then is stored in the hydrogen storage tank; the cleaned oxygen enters the oxygen cooler under the control of the oxygen regulating valve and the check valve to dry and cool the oxygen, and then is stored in the hydrogen storage tank;

[0037] The electrolyte after the reaction in the electrolytic cell, as well as the electrolyte separated and recovered from the hydrogen separator, hydrogen scrubber, oxygen separator and oxygen scrubber, all pass through a heat exchanger and remove possible impurities in a filter; the electrolyte after impurity removal enters an immersion-type energy-free mass transferor, which is separated from the non-pure aqueous solution by a waterproof and breathable layer, allowing only water vapor to pass through, and not allowing liquid water to penetrate and pollute each other; when the immersion-type energy-free mass transferor is immersed in the non-pure aqueous solution, under the action of the interface vapor pressure difference between the immersion-type energy-free mass transferor and the non-pure aqueous solution, the non-pure aqueous solution is gasified on the surface of the waterproof and breathable layer to generate water vapor, and the water vapor enters the electrolyte side of the immersion-type energy-free mass transferor through the waterproof and breathable layer, and induces the water vapor phase change to liquefy under the action of the interface vapor pressure difference to replenish water for the electrolyte; the electrolyte replenished with water is circulated into the electrolytic cell again for electrolysis.

[0038] The vapor pressure difference between the electrolyte and the non-pure aqueous solution at their interface, calculated using seawater with 0.5 M NaCl, has a vapor pressure of 3.131 kPa at room temperature; the vapor pressures of KOH solutions at concentrations of 10 wt%, 20 wt%, 30 wt%, 40 wt%, and 50 wt% are 2.92 kPa, 2.47 kPa, 1.89 kPa, 1.32 kPa, and 0.86 kPa respectively. The vapor pressure differences between the two reach 0.2 kPa, 0.66 kPa, 1.25 kPa, 1.81 kPa, and 2.27 kPa. All of these can enable, under the action of the vapor pressure difference at the interface between the two, the non-pure aqueous solution to undergo gasification on the surface of the waterproof and breathable layer to generate water vapor. The water vapor passes through the waterproof and breathable layer and enters the electrolyte side, and is induced to undergo a phase change to liquefy under the action of the interface vapor pressure difference to supplement water to the electrolyte. In fact, as long as the vapor pressure difference (vapor pressure of the non-pure aqueous solution - vapor pressure of the electrolyte) is greater than 0, water molecules will enter the electrolyte from the non-pure aqueous solution in the form of a "liquid-gas-liquid" phase change migration.

[0039] Compared with the prior art, the positive effects of the present utility model are reflected in:

[0040] (1) This system can realize the direct electrolytic hydrogen production process of non-pure aqueous solutions, and the electrolysis energy consumption is equivalent to that of industrial electrolysis of pure water, without additional desalination / purification energy consumption.

[0041] (2) In the electrolyte circulation and regeneration module, the waterproof and breathable layer isolates the electrolyte from the non-pure aqueous solution to prevent mutual penetration and contamination between the two; in addition, the interface vapor pressure difference between the electrolyte and the non-pure aqueous solution induces the non-pure aqueous solution to undergo a gasification phase change, and the generated water vapor passes through the waterproof and breathable layer and enters the electrolyte side, and is induced to undergo a phase change to liquefy under the action of the interface vapor pressure difference to supplement the water in the electrolyte for electrolysis use; at the same time, electrolysis consumes water synchronously to continuously maintain the interface vapor pressure difference between the electrolyte and the non-pure aqueous solution, thereby continuing to induce water to enter the electrolyte from the non-pure aqueous solution. The realization of this process enables the system to continuously use non-pure aqueous solutions for hydrogen production.

[0042] (3) All devices, components, and units in the present utility model can use existing commercially available and mature items, which greatly ensures the stability and feasibility of the system. Moreover, due to the mature system, it is easy to quickly achieve large-scale preparation.

[0043] (4) The present utility model can directly utilize commercial electrolytic cells and electrolytes, greatly improving the conductivity and electrochemical performance of the electrolysis system, and avoiding the problem of low conductivity and low transfer efficiency at the anode and cathode in direct hydrogen production from non-pure aqueous solutions.

[0044] (5) This system collects hydrogen and oxygen independently, and can simultaneously collect high-purity hydrogen and oxygen.

[0045] (6) The present utility model breaks through the technical bottleneck of traditional non-pure aqueous solution electrolysis for hydrogen production, eliminating the need for non-pure aqueous solution desalination / purification processes. Therefore, there is no need to build large-scale desalination / purification plants, significantly reducing costs in aspects such as construction, operation, manpower, and maintenance. This system can achieve a dynamic continuous hydrogen production process using any aqueous solution without time and space differences. Additionally, it can convert and stably store unstable renewable energy, providing a technical means for the construction of future energy systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a schematic structural diagram of the system for directly electrolyzing non-pure water to produce hydrogen using an immersion-type energy-free mass transfer device according to the present utility model;

[0047] Figure 2 It is a schematic structural diagram of the immersion-type energy-free mass transfer device in Embodiment 5 according to the present utility model;

[0048] Figure 3 It is a schematic structural diagram of the electrolytic cell in Embodiment 5 according to the present utility model;

[0049] Figure 4 The system stability diagram of directly electrolyzing non-pure water to produce hydrogen using an immersion-type energy-free mass transfer device in Embodiment 5 according to the present utility model

[0050] Figure 5 The system stability diagram of directly electrolyzing non-pure water to produce hydrogen using an immersion-type energy-free mass transfer device in Embodiment 6 according to the present utility model

[0051] Figure 6 The system stability diagram of directly electrolyzing non-pure water to produce hydrogen using an immersion-type energy-free mass transfer device in Embodiment 7 according to the present utility model

[0052] Figure 1 Markings and corresponding component names: 1 - energy supply module; 2 - electrolytic cell; 3 - hydrogen separator; 4 - hydrogen scrubber; 5 - hydrogen regulating valve; 6 - check valve I; 7 - hydrogen cooler; 8 - hydrogen storage tank; 9 - oxygen separator; 10 - oxygen scrubber; 11 - oxygen regulating valve; 12 - check valve II; 13 - oxygen cooler; 14 - oxygen storage tank; 15 - radiator; 16 - cooling water tank; 17 - cooling water pump; 18 - heat exchanger; 19 - filter; 20 - immersion-type energy-free mass transfer device; 21 - electrolyte circulation pump; 22 - check valve III; 23 - electrolyte thermostat; DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] In order to make the utility model purpose, technical solution and advantages of the present utility model clearer and more understandable, the following further detailed description of the present utility model is made in conjunction with specific embodiments. However, this should not be construed as limiting the scope of the above-mentioned subject matter of the present utility model to the following embodiments. Without departing from the above-mentioned technical idea of the present utility model, various substitutions and changes made according to common general knowledge and customary means in the art should be included within the scope of the present utility model.

[0054] In the following embodiments, the immersion type energy-free mass transfer device (the structure is shown in Figure 2 ) is used. The immersion type energy-free mass transfer device is a device with a chamber inside, with dimensions of 60 cm × 80 cm × 70 cm. A PTFE porous waterproof and breathable membrane (0.1 micron pore diameter, 60 microns thick) is used as the waterproof and breathable layer in the immersion type energy-free mass transfer device (only set on the top surface of the cuboid), and the rest of the surfaces are made of airtight waterproof and corrosion-resistant materials (such as stainless steel).

[0055] Embodiment 1:

[0056] A system for directly electrolyzing non-pure water to produce hydrogen using an immersion type energy-free mass transfer device. This system is a system for directly electrolyzing non-pure aqueous solutions to produce hydrogen. The system includes an energy supply module, an electrolytic hydrogen production module, and an immersion type electrolyte circulation and regeneration module, where:

[0057] The energy supply module is connected to the electrolytic hydrogen production module; it is used to provide electrical energy for the hydrogen production reaction;

[0058] The electrolytic hydrogen production module includes an electrolytic cell. After the electrolyte is introduced into the electrolytic cell, an oxidation-reduction reaction occurs, consuming water and generating hydrogen and oxygen;

[0059] The immersion type electrolyte circulation and regeneration module is connected to the electrolytic hydrogen production module; it is used to be directly immersed in the non-pure aqueous solution and use the non-pure aqueous solution to supplement pure water to the electrolyte.

[0060] The energy source of the energy supply module is the electrical energy converted from traditional coal power or renewable energy; such as solar energy, wind energy, etc.

[0061] After the electrolytic hydrogen production work is completed in the electrolytic hydrogen production module, the electrolytic cell is any one of an alkaline electrolytic cell (AWE), a (proton exchange membrane) PEM electrolytic cell, an (anion exchange membrane) AEM electrolytic cell, or a combination formed by series or parallel connection of any one electrolytic cell. The electrolyte filled in the electrolytic cell is a liquid electrolyte or a solid gel electrolyte; where the liquid electrolyte is a liquid with a low saturation and having the function of absorbing water vapor; where the solid electrolyte is a substance that induces the phase change of water vapor to liquefy.

[0062] The described immersion electrolyte circulation regeneration module includes an immersion energy-free mass transfer device, which is a device with a waterproof and breathable layer (for example, a chamber with a waterproof and breathable layer partially or entirely provided on any side and the remaining sides made of waterproof and corrosion-resistant materials; the electrolyte is pumped in through the opened holes in advance and then the holes are sealed; the immersion energy-free mass transfer device can also be a three-dimensional chamber with waterproof and breathable layers on any two sides, any three sides, any four sides or all sides). The immersion energy-free mass transfer device with a waterproof and breathable layer is placed in a non-pure aqueous solution, and the waterproof and breathable layer isolates the electrolyte in the cavity of the immersion energy-free mass transfer device, preventing the electrolyte and the non-pure aqueous solution from penetrating each other; it is a module for realizing the "liquid-gas-liquid" phase change migration process, and this module uses the non-pure aqueous solution to directly supplement pure water to the relatively high-concentration electrolyte solution. The immersion energy-free mass transfer device is a device capable of realizing the "liquid-gas-liquid" phase change migration process; when the immersion energy-free mass transfer device is immersed in the non-pure aqueous solution, the interfacial vapor pressure difference between the non-pure aqueous solution and the electrolyte in the immersion energy-free mass transfer device causes the non-pure aqueous solution to undergo phase change gasification (the saturated vapor pressure of the electrolyte is lower than that of the non-pure aqueous solution), and the generated water vapor enters the immersion energy-free mass transfer device through the waterproof and breathable layer, and under the action of the interfacial vapor pressure difference, the water vapor is induced to liquefy and undergo a secondary phase change, realizing the "liquid-gas-liquid" phase change migration process; in addition, the waterproof and breathable layer blocks the impurities in the non-pure aqueous solution and prevents the mutual penetration and pollution of the electrolyte and the non-pure aqueous solution.

[0063] The described non-pure aqueous solution is selected from seawater, river water, lake water, wastewater or domestic sewage.

[0064] The waterproof and breathable layer in the immersion energy-free mass transfer device is a commercially mature waterproof and breathable layer, or is selected from any one of porous TPU membranes, PDMS, and PTFE membranes, or a porous waterproof and breathable mass transfer layer prepared by spraying, screen printing or electrospinning processes using graphene, PVDF particles, and PTFE particles.

[0065] More preferably, the electrolytic hydrogen production module includes an electrolytic cell and an electrolyte temperature controller; the electrolytic cell and the electrolyte temperature controller are connected.

[0066] The electrolyte circulation regeneration module includes an immersion energy-free mass transfer device, a heat exchanger, a filter, an electrolyte circulation pump, and an electrolyte check valve; both the anode and cathode of the electrolytic cell are connected to the heat exchanger, and after the heat exchanger is connected to the filter, it is connected to the immersion energy-free mass transfer device; the immersion energy-free mass transfer device is connected to the electrolyte temperature controller of the electrolytic hydrogen production module through the electrolyte circulation pump and the electrolyte check valve.

[0067] The electrolyte filled in the electrolytic cell and the electrolyte mass transfer chamber of the energy-free mass transfer device is a liquid electrolyte or a solid gel electrolyte; the liquid electrolyte is a liquid with a low saturated water vapor pressure or a function of absorbing water vapor, including alkaline liquid electrolytes, acidic liquid electrolytes, and ionic liquids; the alkaline liquid electrolytes are selected from one of KOH solution, K2CO3 solution, KHCO3 solution, NaOH solution, Na2CO3 solution, NaHCO3 solution, K3PO4 solution, CH3COOK solution, Ca(OH)2 and other alkaline substances, or their combinations. Acidic liquid electrolytes such as: H2SO4 solution, H3PO4 solution and other acidic substances, or their combinations. Ionic liquids such as: 1-ethyl-3-methylimidazolium acetate, etc. Organic hygroscopic liquids: PEG, etc. The solid electrolyte is a substance that induces the phase change and liquefaction of water vapor. Solid gel electrolytes such as: polyacrylamide hydrogel, poly(sulfonic acid group acrylamide) hydrogel, poly(methacrylamide) hydrogel, poly(benzyl acrylamide) hydrogel, poly(phenyl acrylamide) hydrogel, poly(ethyl acrylamide) hydrogel, poly(tert-butyl acrylamide) hydrogel, etc., any one of the hygroscopic gels with hydrophilic groups such as hydroxyl group, sulfonic acid group, carboxyl group, amine group, ether group, or their combinations.

[0068] A non-aqueous solution thermostat is provided between the non-aqueous solution circulation pump and the submerged energy-free mass transfer device, and the vapor pressure of the non-aqueous solution can be adjusted by controlling the temperature of the non-aqueous solution.

[0069] Preferably, all components in the system device are connected to the control system for automating the control system process.

[0070] Example 2:

[0071] On the basis of Example 1, the system for directly electrolyzing non-pure water to produce hydrogen using a submerged energy-free mass transfer device further includes a hydrogen collection module and an oxygen collection module; the hydrogen collection module includes a hydrogen separator, a hydrogen scrubber, a hydrogen cooler and a hydrogen storage tank; the oxygen collection module includes an oxygen separator, an oxygen scrubber, an oxygen cooler and an oxygen storage tank; the hydrogen separator and the oxygen separator are respectively connected to the electrolytic cell, and a hydrogen scrubber, a hydrogen cooler and a hydrogen storage tank are sequentially connected after the hydrogen separator; an oxygen scrubber, an oxygen cooler and an oxygen storage tank are sequentially connected after the oxygen separator. It is used to separate the electrolyte / water entrained in hydrogen and oxygen, and at the same time wash, dry and store the collected gas.

[0072] Preferably, a hydrogen regulating valve and a check valve are provided between the hydrogen scrubber and the hydrogen cooler; an oxygen regulating valve and a check valve are provided between the oxygen scrubber and the oxygen cooler.

[0073] Example 3:

[0074] Based on Embodiment 2, the electrolytic hydrogen production system without pure water further includes a cooling module, which includes a radiator, a cooling water tank, and a cooling water pump; the cooling water tank is connected to the radiator and is connected to the hydrogen separator, hydrogen scrubber, hydrogen cooler, oxygen separator, oxygen scrubber, oxygen cooler, and heat exchanger through the cooling water pump to provide cooling water.

[0075] Furthermore, the electrolyte pumped out of the electrolytic cell and the electrolytes collected in the hydrogen separator, oxygen separator, hydrogen scrubber, and oxygen scrubber enter the immersion type energy-free mass transfer device after passing through the heat exchanger and filter.

[0076] Furthermore, each module in this system is connected to the control system for automated control of the process.

[0077] Embodiment 4:

[0078] A system for directly electrolyzing non-pure water to produce hydrogen using an immersion type energy-free mass transfer device, the structure of which is further described based on Embodiment 3: The specific structure of the system is as follows: It includes an energy supply module, an electrolytic cell, a hydrogen separator, a hydrogen scrubber, a hydrogen regulating valve, a hydrogen check valve, a hydrogen cooler, a hydrogen storage tank, an oxygen separator, an oxygen scrubber, an oxygen regulating valve, an oxygen check valve, an oxygen cooler, an oxygen storage tank, a radiator, a cooling water tank, a cooling water pump, a heat exchanger, a filter, an immersion type energy-free mass transfer device, an electrolyte circulation pump, an electrolyte check valve, and an electrolyte temperature controller; among them, the immersion type energy-free mass transfer device is a device that can realize the "liquid-gas-liquid" phase change migration process. When the immersion type energy-free mass transfer device is immersed in a non-pure aqueous solution, the non-pure aqueous solution spontaneously supplements pure water to the electrolyte in the immersion type energy-free mass transfer device; the energy supply module is connected to the anode and cathode of the electrolytic cell to provide electrical energy; a hydrogen separator is arranged on the cathode side of the electrolytic cell, and a hydrogen scrubber, a hydrogen regulating valve, a hydrogen check valve, a hydrogen cooler, and a hydrogen storage tank are arranged in sequence behind the hydrogen separator; an oxygen separator is arranged on the anode side of the electrolytic cell, and an oxygen scrubber, an oxygen regulating valve, an oxygen check valve, an oxygen cooler, and an oxygen storage tank are arranged in sequence behind the oxygen separator; the electrolytic cell, hydrogen separator, and oxygen separator are all connected to the heat exchanger, and the heat exchanger is connected to the filter and then communicated with the immersion type energy-free mass transfer device; the immersion type energy-free mass transfer device is connected to the electrolyte temperature controller through the electrolyte circulation pump and the electrolyte check valve, and the electrolyte temperature controller is connected to the electrolytic cell; the cooling water tank is connected to the hydrogen separator, hydrogen scrubber, hydrogen cooler, oxygen separator, oxygen scrubber, oxygen cooler, and heat exchanger respectively through the cooling water pump.

[0079] The process of electrolyzing non-pure water to produce hydrogen without using pure water using the non-pure aqueous solution direct electrolytic hydrogen production system described above includes the following steps:

[0080] First, the electrolyte is introduced into the cathode of the electrolytic cell, or the anode, or both the anode and cathode simultaneously, and an oxidation-reduction reaction occurs to generate hydrogen and oxygen;

[0081] If the electrolytic cell is an alkaline electrolytic cell or an AEM electrolytic cell, the electrolyte first undergoes a reduction hydrogen evolution reaction at the cathode, and the generated OH - enters the anode through a diaphragm or an anion exchange membrane and undergoes an oxidation reaction to generate oxygen; if the electrolytic cell is a PEM electrolytic cell, the electrolyte first undergoes an oxidation oxygen evolution reaction at the anode, and the generated H + enters the cathode through a proton exchange membrane and undergoes a reduction reaction to generate hydrogen;

[0082] The generated hydrogen and oxygen respectively enter a hydrogen separator and an oxygen separator, and in this process, the generated hydrogen and oxygen are separated from the entrained electrolyte or moisture; the separated hydrogen and oxygen respectively enter a hydrogen scrubber and an oxygen scrubber, and in this process, the electrolyte and moisture that are not completely separated in the gas are further thoroughly cleaned; the cleaned hydrogen, under the control and regulation of a hydrogen regulating valve and a check valve, enters a hydrogen cooler to dry and cool the hydrogen, and then is stored in a hydrogen storage tank; the cleaned oxygen, under the control and regulation of an oxygen regulating valve and a check valve, enters an oxygen cooler to dry and cool the oxygen, and then is stored in a hydrogen storage tank;

[0083] The electrolyte after the reaction in the electrolytic cell, as well as the electrolyte separated and recovered from the hydrogen separator, hydrogen scrubber, oxygen separator, and oxygen scrubber, all pass through a heat exchanger and impurities that may be carried are removed in a filter; the electrolyte after impurity removal enters an immersion type energy-free mass transfer device, and the immersion type energy-free mass transfer device and the non-aqueous solution are separated by a waterproof and breathable layer, which only allows water vapor to pass through and does not allow liquid water to penetrate and contaminate each other; when the immersion type energy-free mass transfer device is immersed in the non-aqueous solution, under the action of the vapor pressure difference at the interface between the immersion type energy-free mass transfer device and the non-aqueous solution, the non-aqueous solution undergoes a gasification effect on the surface of the waterproof and breathable layer to generate water vapor, and the water vapor passes through the waterproof and breathable layer and enters the electrolyte side of the immersion type energy-free mass transfer device, and under the action of the interface vapor pressure difference, the water vapor is induced to undergo a phase change and liquefy to supplement water for the electrolyte; the electrolyte supplemented with water is recycled into the electrolytic cell for electrolysis again.

[0084] Example 5: Electrolytic hydrogen production is carried out using a system for directly electrolyzing non-pure water to produce hydrogen using an immersion type energy-free mass transfer device described in any one of Examples 1 - 4.

[0085] Specific operation: Both the immersion type energy-free mass transfer device ( Figure 2 ) and the electrolytic cell are filled with a 30 wt% potassium hydroxide solution as the electrolyte solution; the electrolytic cell is a self-made electrolytic cell (the structure is shown in Figure 3) It is composed of 11 electrolysis units connected in parallel. Nickel foam molybdenum is used as the anode catalyst, nickel-plated platinum mesh is used as the cathode catalyst, polysulfone membrane is used as the diaphragm, and non-pure aqueous solution is the seawater of Shenzhen Bay. Figure 4 At 250 mA / cm 2 The test was carried out under such conditions. Among them, the seawater is calculated by 0.5 M NaCl. Its vapor pressure at room temperature is 3.131 kPa. The vapor pressure of KOH solution is 1.89 kPa when the concentration is 30 wt%. The vapor pressure difference between the two is 1.25 kPa. The device operates stably in the seawater of Shenzhen Bay for 1000 h, and the actual voltage of the stack is about 2.06 V.

[0086] Other implementation methods of using this system, the differences and results are shown in Table 1:

[0087]

[0088]

[0089] Example 6:

[0090] An electrolytic hydrogen production system using an immersion type energy-free mass transfer device described in Example 1 was used for electrolytic hydrogen production.

[0091] Specific operation: Both the immersion type energy-free mass transfer device and the electrolytic cell are filled with 30 wt% potassium hydroxide solution as the electrolyte solution. A commercial alkaline electrolytic cell is used as the electrolytic hydrogen production reactor. The non-pure aqueous solution and the electrolyte solution are both at room temperature. At 250 mA / cm 2 The test was carried out under such conditions, and the experimental results are as Figure 5 . Among them, the seawater is calculated by 0.5 M NaCl. Its vapor pressure at room temperature is 3.131 kPa. The vapor pressure of KOH solution is 1.89 kPa when the concentration is 30 wt%. The vapor pressure difference between the two is 1.25 kPa. As Figure 5 The device operates stably in the seawater of Shenzhen Bay for 500 h, and the actual voltage of the stack is about 2 V. It shows that this system can stably produce hydrogen without additional energy consumption, and the energy consumption is similar to that of electrolyzing pure water.

[0092] Other implementation modes of using this system, the differences and results are shown in Table 2: (The seawater is calculated by 0.5 M NaCl, and its vapor pressure at room temperature is 3.131 kPa; the vapor pressures of KOH solution at concentrations of 10 wt%, 20 wt%, 30 wt%, 40 wt% and 50 wt% are 2.92 kPa, 2.47 kPa, 1.89 kPa, 1.32 kPa and 0.86 kPa respectively, and the vapor pressure differences between the two reach 0.2 kPa, 0.66 kPa, 1.25 kPa, 1.81 kPa and 2.27 kPa)

[0093]

[0094]

[0095]

[0096]

[0097] Example 7:

[0098] Hydrogen production by direct electrolysis of non-pure water is carried out using the system for producing hydrogen by direct electrolysis of non-pure water using an immersion type energy-free mass transfer device described in Example 1.

[0099] Specific operation: Both the immersion type energy-free mass transfer device and the electrolytic cell are filled with 15 wt% sulfuric acid solution as the electrolyte solution. A commercial PEM electrolytic cell is used as the hydrogen production reactor by electrolysis. The non-pure aqueous solution and the electrolyte solution are both at room temperature. The test is carried out under the condition of 250 mA / cm 2 conditions, and the experimental results are as Figure 6 . As Figure 6 This device operates stably in the sea water of Shenzhen Bay for 100 h, and the actual voltage of the electrolytic cell is about 1.9 V. It shows that this system can stably produce hydrogen without additional energy consumption, and the energy consumption is similar to that of electrolyzing pure water.

[0100] Other implementation methods of using this system, the differences and results are shown in Table 3:

[0101]

[0102]

[0103] The above are only the preferred embodiments of the present invention, and are not used to limit the present invention. For those of ordinary skill in the art of this technology, improvements or changes can also be made according to the above description. All these improvements and changes should fall within the protection scope of the appended claims of the present invention.

Claims

1. A system for directly electrolyzing non-pure water to produce hydrogen using an immersion-type energy-free mass transfer device. This system is a direct electrolysis hydrogen production system for non-pure aqueous solutions, and is characterized in that The system includes an energy supply module, an electrolytic hydrogen production module, and an immersion electrolyte circulation and regeneration module, where: The energy supply module is connected to the electrolytic hydrogen production module; The immersion electrolyte circulation and regeneration module is connected to the electrolytic hydrogen production module; the immersion electrolyte circulation and regeneration module includes an immersion energy-free mass transfer device; the immersion energy-free mass transfer device is a hollow device including a waterproof and breathable layer; the immersion energy-free mass transfer device has a waterproof and breathable layer provided on any one side of the outer surface of the chamber, and the remaining sides are made of waterproof and corrosion-resistant materials; or the waterproof and breathable layer is provided on any two sides, any three sides, any four sides, any five sides or six sides of the outer surface of the hollow chamber device; when the immersion energy-free mass transfer device is an irregular hollow chamber, all its surfaces are made of waterproof and breathable layers.

2. The system for directly electrolyzing non-pure water to produce hydrogen by using an immersion-type energy-free mass transfer device as described in claim 1, wherein: The electrolytic hydrogen production module includes an electrolytic cell, which can be any one of an alkaline electrolytic cell, a PEM electrolytic cell, and an AEM electrolytic cell, or a combination formed by series or parallel connection of any one of the electrolytic cells.

3. The system for directly electrolyzing non-pure water to produce hydrogen by using an immersion-type energy-free mass transfer device as claimed in claim 1 or 2, characterized in that: The system further includes a hydrogen collection module and an oxygen collection module; The hydrogen collection module includes a hydrogen separator, a hydrogen scrubber, a hydrogen cooler, and a hydrogen storage tank; the oxygen collection module includes an oxygen separator, an oxygen scrubber, an oxygen cooler, and an oxygen storage tank; both the hydrogen separator and the oxygen separator are respectively connected to the electrolytic cell, and a hydrogen scrubber, a hydrogen cooler, and a hydrogen storage tank are sequentially connected after the hydrogen separator; an oxygen scrubber, an oxygen cooler, and an oxygen storage tank are sequentially connected after the oxygen separator.

4. The system for directly electrolyzing non-pure water to produce hydrogen by using an immersion type energy-free mass transfer device as claimed in claim 3, wherein: The system further includes a cooling module, which includes a radiator, a cooling water tank, and a cooling water pump; the cooling water tank is connected to the radiator, and the cooling water tank is connected to the hydrogen separator, the hydrogen scrubber, the hydrogen cooler, the oxygen separator, the oxygen scrubber, the oxygen cooler, and the heat exchanger through the cooling water pump.

5. The system for directly electrolyzing non-pure water to produce hydrogen by using an immersion type energy-free mass transfer device as claimed in claim 3, wherein: The electrolytic cell, the hydrogen separator, the oxygen separator, the hydrogen scrubber, and the oxygen scrubber are all connected to the immersion energy-free mass transfer device through a heat exchanger and a filter.

6. The system for directly electrolyzing non-pure water to produce hydrogen by using an immersion-type energy-free mass transfer device as claimed in claim 4, wherein: All modules in the system are connected to the control system.

7. A system for directly electrolyzing non-pure water to produce hydrogen using an immersion-type energy-free mass transfer device, characterized in that The immersion type energy-free mass transfer device is a device including a waterproof and breathable layer; specifically, the immersion type energy-free mass transfer device is a container with a waterproof and breathable layer provided on any one or more surfaces and filled with an electrolyte inside; this system is a non-pure aqueous solution direct electrolysis hydrogen production system, including an energy supply module, an electrolytic cell, a hydrogen separator, a hydrogen scrubber, a hydrogen regulating valve, a hydrogen check valve, a hydrogen cooler, a hydrogen storage tank, an oxygen separator, an oxygen scrubber, an oxygen regulating valve, an oxygen check valve, an oxygen cooler, an oxygen storage tank, a radiator, a cooling water tank, a cooling water pump, a heat exchanger, a filter, an immersion type energy-free mass transfer device, an electrolyte circulation pump, an electrolyte check valve, and an electrolyte thermostat; among them, the energy supply module is connected to the anode and cathode of the electrolytic cell; a hydrogen separator is arranged on the cathode side of the electrolytic cell, and a hydrogen scrubber, a hydrogen regulating valve, a hydrogen check valve, a hydrogen cooler, and a hydrogen storage tank are successively arranged behind the hydrogen separator; an oxygen separator is arranged on the anode side of the electrolytic cell, and an oxygen scrubber, an oxygen regulating valve, an oxygen check valve, an oxygen cooler, and an oxygen storage tank are successively arranged behind the oxygen separator; the electrolytic cell, the hydrogen separator, and the oxygen separator are all connected to the heat exchanger, and after the heat exchanger is connected to the filter, it is communicated with the immersion type energy-free mass transfer device; the immersion type energy-free mass transfer device is connected to the electrolyte thermostat through the electrolyte circulation pump and the electrolyte check valve, and the electrolyte thermostat is connected to the electrolytic cell; the cooling water tank is respectively connected to the hydrogen separator, the hydrogen scrubber, the hydrogen cooler, the oxygen separator, the oxygen scrubber, the oxygen cooler, and the heat exchanger through the cooling water pump.

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