Membrane module supported three-phase interface photocatalytic reaction device and method
By forming a three-phase interface on the surface of the gas diffusion layer and utilizing an ion exchange membrane to achieve the circulation of the redox medium, the problem of low CO2 mass transfer efficiency is solved, the overall efficiency and selectivity of the reactor are improved, and the reactor structure is simplified.
Patent Information
- Application Number
- CN202511857691.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-10
- Publication Date
- 2026-02-27
AI Technical Summary
In existing liquid-solid phase photocatalytic reactors, CO2 has low mass transfer efficiency, and oxidation and reduction products are easily mixed, resulting in low reaction rates and poor selectivity.
A membrane module-supported three-phase interface photocatalytic reaction device is designed. By forming a CO2-liquid-catalyst three-phase interface on the surface of the gas diffusion layer, the oxidation-reduction medium is circulated and regenerated using an ion exchange membrane, which promotes CO2 mass transfer and increases the CO2 concentration on the catalyst surface.
It significantly improved the CO2 mass transfer efficiency, enhanced the CO2 concentration on the catalyst surface, improved the overall reaction efficiency, suppressed the reverse reaction, simplified the reactor structure, and enabled the recycling of the medium.
Smart Images
Figure CN121571086A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of carbon capture and conversion utilization, and particularly relates to a membrane assembly supported three-phase interface photocatalytic reaction device and method. BACKGROUND
[0002] The combustion of fossil fuels releases a large amount of greenhouse gases dominated by CO2, causing a sustained increase in the average global temperature. In this context, CO2 emission reduction and resource conversion technology has become a global research hotspot. Photocatalytic CO2 reduction technology is considered to be a promising technology for simultaneously solving environmental and energy problems, because it can convert CO2 into hydrocarbon fuels or high-value chemicals, and realize artificial carbon cycle, by taking energy from renewable solar energy.
[0003] In order to improve the efficiency of photocatalytic conversion of CO2, in addition to developing high-performance photocatalysts, optimizing the design of the photo reactor is also important. Efficient mass transfer of CO2 and water, charge separation, and catalyst-reactant interaction are the keys to photocatalytic reaction. Therefore, a carefully designed photo reactor structure is needed. The traditional liquid-solid phase reactor has problems such as low CO2 mass transfer efficiency and easy mixing of oxidation and reduction products. The dual reactor simulating natural photosynthesis has two chambers, which can carry out oxidation and reduction reactions in different chambers, thereby inhibiting reverse reactions and improving product selectivity. However, in the current dual reactor, the reduction side and the oxidation side are both liquid-solid two-phase reaction systems. The poor solubility of CO2 and the limited diffusion coefficient in the liquid phase still significantly weaken the overall reaction rate. SUMMARY
[0004] The purpose of the present application is to overcome the problems in the prior art, provide a membrane assembly supported three-phase interface photocatalytic reaction device and method, which can form a three-phase (gas-liquid-solid) interface at the catalyst on the surface of the gas diffusion layer, significantly promote the mass transfer of CO2, increase the CO2 concentration on the catalyst surface, thereby improving the overall reaction efficiency, and overcoming the problem of low reaction rate caused by poor solubility and diffusion coefficient of CO2 in the liquid. 二氧化碳 -liquid 溶液 -solid 催化剂 ) interface at the catalyst on the surface of the gas diffusion layer, significantly promote the mass transfer of CO2, increase the CO2 concentration on the catalyst surface, thereby improving the overall reaction efficiency, and overcoming the problem of low reaction rate caused by poor solubility and diffusion coefficient of CO2 in the liquid.
[0005] The membrane assembly supported three-phase interface photocatalytic reaction device provided by the present application comprises an oxidation medium flow channel shell, a CO2 gas flow channel shell and a reduction medium flow channel shell which are sequentially stacked and fixedly connected; the internal cavity of the oxidation medium flow channel shell constitutes an oxidation medium flow channel; the internal cavity of the CO2 gas flow channel shell constitutes a CO2 gas flow channel; and the internal cavity of the reduction medium flow channel shell constitutes a reduction medium flow channel. The oxidation medium flow channel shell and the CO2 gas flow channel shell both have an open side, and a gas diffusion layer is arranged at the open side, and the side of the gas diffusion layer facing the oxidation medium flow channel is loaded with a CO2 reduction catalyst; an ion exchange membrane is arranged between the oxidation medium flow channel shell and the reduction medium flow channel shell at a position corresponding to the peripheral side of the CO2 gas flow channel shell, so that the oxidation medium flow channel shell and the reduction medium flow channel shell realize ion exchange; a water oxidation catalyst carrier film is arranged in the reduction medium flow channel, and the water oxidation catalyst carrier film is loaded with a water oxidation catalyst, and the oxidation medium flow channel shell and the reduction medium flow channel shell are both provided with a light window at a position corresponding to the opposite side walls of the CO2 reduction catalyst and the water oxidation catalyst.
[0006] Preferably, the oxidation medium flow channel and the reduction medium flow channel are used to fill oxidation medium and reduction medium solutions, and the oxidation medium and the reduction medium are oxidation-reduction couples capable of ion exchange through the ion exchange membrane and mutual conversion.
[0007] Preferably, the CO2 gas flow channel shell is provided with a gas inlet and a gas outlet, and the oxidation medium flow channel shell and the reduction medium flow channel shell are both provided with a liquid inlet and a liquid outlet.
[0008] Preferably, the gas diffusion layer has a hydrophobic property.
[0009] Preferably, the CO2 gas flow channel is in the shape of a parallel flow channel, a biomimetic flow channel, a snake-shaped flow channel or a spiral flow channel, and the light window light transmission area covers the CO2 gas flow channel.
[0010] Preferably, the coating shape of the CO2 reduction catalyst, the projection shape of the CO2 gas flow channel (6) on the gas diffusion layer (5) and the shape of the light window on the corresponding side are the same, and the coating shape of the water oxidation catalyst is the same as the shape of the light window on the corresponding side.
[0011] Preferably, the CO2 gas flow channel shell, the oxidation medium flow channel shell and the reduction medium flow channel shell are all made of acid- and alkali-resistant and high-temperature-resistant materials, and the light window is made of a corrosion-resistant and light-transmitting material.
[0012] The second object of the present application is to provide a method for supporting the three-phase interface photocatalytic reaction device of the above-mentioned membrane assembly, which comprises: CO2 gas is introduced into the CO2 gas flow channel, oxidation medium solution and reduction medium solution are respectively introduced into the oxidation medium flow channel and the reduction medium flow channel, and light is provided to the CO2 reduction catalyst and the water oxidation catalyst through the light window. In this process, on the CO2 reduction side, CO2 is photocatalytically reduced at the three-phase interface of the gas diffusion layer, while the oxidation medium is oxidized; on the water oxidation side, water is photocatalytically oxidized, while the reduction medium is reduced; the oxidized oxidation medium and the reduced reduction medium diffuse into each other through the ion exchange membrane and achieve regeneration on the opposite side, forming a cycle.
[0013] Preferably, the oxidizing medium is a FeSO4 solution, the reducing medium is a Fe2(SO4)3 solution, and the ion exchange membrane is a cation exchange membrane.
[0014] Compared with the prior art, the beneficial effects of the present invention are: The membrane module-supported three-phase interface photocatalytic reaction device provided by this invention forms a three-phase (gas-diffusing) reaction at the catalyst loaded on the surface of the gas diffusion layer. 二氧化碳 -liquid 溶液 -solid 催化剂 The interface significantly promotes CO2 mass transfer, increases the CO2 concentration on the catalyst surface, thereby improving the overall reaction efficiency and overcoming the problem of low reaction rate caused by the poor solubility and diffusion coefficient of CO2 in liquid.
[0015] This invention forms a spatial separation reactor system for CO2 reduction and water oxidation through the shuttle and regeneration cycle of redox media, avoiding the separation of oxygen and CO2 reduction gas products, while suppressing the occurrence of potential reverse reactions.
[0016] In this invention, the redox medium undergoes a reaction and then exchanges mass through an ion exchange membrane, achieving a cyclic reaction of the redox medium within the device. This simplifies the reactor and avoids the need for replenishment of the medium during the reaction process. The device boasts advantages such as simple structure and high conversion efficiency.
[0017] The three-phase interface photocatalytic reactor supported by this membrane module can flexibly adjust the composition of the redox medium and the selection of the catalyst in the relevant flow channels according to actual needs, so that it can achieve the most complete catalytic reduction reaction in different practical scenarios and improve the versatility of the device. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structural composition of the present invention; Figure 2 This is a schematic diagram of the overall appearance of the present invention; Figure 3 This is a schematic diagram of the internal cross-section and mass transfer of the present invention.
[0019] Figure 4 This is a schematic diagram of the CO2 flow channel of the present invention.
[0020] Explanation of reference numerals in the attached figures: 1, CO2 reduction side light window, 2, oxidation medium flow channel shell, 3, ion exchange membrane, 4, CO2 reduction catalyst, 5, gas diffusion layer, 6, CO2 gas flow channel, 7, CO2 flow channel shell, 8, reduction medium flow channel, 9, water oxidation catalyst, 10, reduction medium flow channel shell, 11, water oxidation side light window, 12, water oxidation catalyst carrier film, 13, oxidation medium flow channel, 14, oxidation medium inlet, 15, oxidation medium outlet, 16, CO2 gas inlet, 17, CO2 gas outlet, 18, reduction medium inlet, 19, reduction medium outlet, 20, reactor fixing bolt hole, 21, light window fixing screw hole. DETAILED DESCRIPTION
[0021] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below with reference to the drawings of the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the described embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of protection of the present application.
[0022] Unless otherwise defined, technical terms or scientific terms used herein should be understood as having the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms "first", "second", and similar terms used herein do not denote any order, quantity, or importance, but are used to distinguish different components. The terms "include" or "contain" and similar terms mean that the elements or objects appearing before "include" or "contain" cover the elements or objects listed after "include" or "contain" and their equivalents, and do not exclude other elements or objects. The terms "connected" or "connected" and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to represent relative positional relationships, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.
[0023] The film assembly supported three-phase interface photocatalytic reaction device provided by the present application comprises an oxidation medium flow channel shell, a CO2 gas flow channel shell and a reduction medium flow channel shell which are sequentially stacked and fixedly connected; the internal cavity of the oxidation medium flow channel shell constitutes an oxidation medium flow channel; the internal cavity of the CO2 gas flow channel shell constitutes a CO2 gas flow channel; the internal cavity of the reduction medium flow channel shell constitutes a reduction medium flow channel; the oxidation medium flow channel 13 and the CO2 gas flow channel 6 are separated by a gas diffusion layer 5 coated with a CO2 reduction catalyst 4; the oxidation medium flow channel 13 and the reduction medium flow channel 8 are separated by an ion exchange membrane 3.
[0024] The embodiment provides a three-phase interface photocatalytic reaction device supported by a membrane assembly, which can realize spatial separation of CO2 reduction and water oxidation and circulation of redox media, wherein the gas diffusion layer in the embodiment is loaded with a CO2 reduction catalyst, and CO2 can be continuously transported to the surface of the photocatalyst with the help of the hydrophobic surface, instead of relying on trace CO2 dissolved in the liquid phase, so that CO2 reduction occurs at the three-phase interface, the CO2 concentration on the surface of the catalyst is improved, and the overall reaction efficiency is improved. The device of the embodiment has the advantages of simple structure, and can flexibly adjust the selection of related catalysts and the composition of the redox media in the flow channel according to actual needs, so that the most sufficient catalytic reduction reaction can be realized in different practical scenes, and the device has universality.
[0025] The three-chamber reactor provided by the embodiment realizes spatial separation of CO2 reduction and water oxidation through shuttle and regeneration circulation of redox media, and can inhibit potential reverse reactions. In addition, the three-phase interface on the CO2 reduction side significantly enhances CO2 mass transfer, thereby improving the overall reaction efficiency.
[0026] As a preferred embodiment, the CO2 gas flow channel shell is provided with a gas inlet and a gas outlet, the oxidation medium flow channel shell and the reduction medium flow channel shell are each provided with a liquid inlet and a liquid outlet, and further preferably, the shape of the CO2 flow channel is selected as a serpentine flow channel, but is not limited to a serpentine flow channel, and can also be selected according to specific needs, for example, the shape of the CO2 gas flow channel can also be a parallel flow channel, a biomimetic flow channel or a spiral flow channel, and as a more preferred embodiment, the light window light transmission region covers the CO2 gas flow channel.
[0027] As a preferred embodiment, the coating shape of the CO2 reduction catalyst in the embodiment, the projection shape of the CO2 gas flow channel (6) on the gas diffusion layer (5) and the shape of the light window on the corresponding side are the same, and the coating shape of the water oxidation catalyst is the same as the shape of the light window on the corresponding side. When the coating shape of the catalyst is completely consistent with the shape of the light window, the light transmission region covers the catalyst active region; for example, the shape of the CO2 gas flow channel is a serpentine flow channel, and the catalyst and the light window are also matched serpentine strips, so that CO2 gas will flow along the catalytic reaction zone that needs it, and the gas distribution corresponds to the reaction demand in space, avoiding invalid flow in the non-reaction zone; therefore, when the shapes of the three are consistent, the flow at each position in the flow channel is guided to the effective reaction region, greatly improving the utilization efficiency of the reactants and the overall mass transfer efficiency.
[0028] Meanwhile, since the light, flow and catalysis are integrated in the embodiment, the reaction rate, temperature field and concentration field distribution on the whole reaction interface are more uniform. The generation of local overheating points or reactant deficiency points is reduced, thereby improving the product selectivity and reducing the risk of catalyst falling off caused by thermal stress and the like.
[0029] As a preferred embodiment, the oxidation medium flow channel 13 and the reduction medium flow channel 8 are respectively filled with an oxidation medium and a reduction medium solution. Further preferably, the oxidation medium is selected as a 5 mM FeSO4 solution, and the reduction medium is selected as a 5 mM Fe2(SO4)3 solution, but is not limited to the above-mentioned solutions, and can be other solutions that can be converted by sacrificial photogenerated holes and photogenerated electrons and can pass through the ion exchange membrane.
[0030] As a preferred embodiment, the oxidation medium flow channel shell 2, the CO2 gas flow channel shell 7, the reduction medium flow channel shell 10, and the internal material are all acid and alkali resistant, high temperature resistant materials, and the light windows 1 and 11 are all corrosion resistant and transparent materials. Further preferably, the flow channel shell material is selected as a titanium plate, but is not limited to a titanium plate, and can be other corrosion resistant materials; the light window material is selected as quartz glass, but is not limited to quartz glass, and can be other transparent materials.
[0031] As a preferred embodiment, the gas diffusion layer 5 loaded with the CO2 reduction catalyst 4 has a hydrophobic property; and the carrier 12 of the water oxidation catalyst 9 can be a certain film material with a supporting property. Further preferably, the gas diffusion layer 5 and the carrier 12 are selected as hydrophobic PTFE films, and can also be other hydrophobic film materials that can load catalysts.
[0032] As a preferred embodiment, the CO2 reduction catalyst 4 and the water oxidation catalyst 9 are both oriented towards the liquid side, and light passes through the liquid to the surface of the catalyst.
[0033] As a preferred embodiment, on the CO2 reduction side, the light excites the catalyst to generate photogenerated electrons to reduce CO2 into products such as CO, CH4, and C2H4, and the reduction medium is oxidized by photogenerated holes; on the water oxidation side, photogenerated holes oxidize water into O2, and the oxidation medium is reduced by photogenerated electrons. After the reduction and oxidation of the oxidation / reduction medium, the concentration gradient caused by the photo-reaction is reversed and diffuses through the ion membrane 3 to the opposite side, where it is regenerated and recycled. Further, the ion membrane is selected as a cation membrane, and can also be other membrane materials that can exchange the selected oxidation / reduction medium.
[0034] As a preferred embodiment, the CO2 reduction catalyst can be a catalytic material that catalyzes the reduction of CO2; and the water oxidation catalyst can be a catalytic material that catalyzes the oxidation of water. Further preferably, the CO2 reduction catalyst is selected as TiO2, and can also be other catalytic materials that can photocatalyze the reduction and conversion of CO2; and the water oxidation catalyst is selected as g-C3N4, and can also be other catalytic materials that can photocatalyze the oxidation and conversion of H2O.
[0035] As a preferred embodiment, the light source irradiates the catalyst surface through the light window; the FeSO4 solution enters the oxidation medium flow channel through the inlet; the Fe2(SO4)3 solution enters the reduction medium flow channel through the inlet; the CO2 enters the CO2 flow channel through the gas inlet and gathers on the TiO2 catalyst surface through the PTFE hydrophobic membrane; at this time, a three-phase (gas 二氧化碳 -liquid 溶液 -solid 催化剂 ) interface is formed on the TiO2 catalyst surface, and the CO2 concentration on the catalyst surface is increased. The photoexcited TiO2 catalyst generates photoelectrons to reduce CO2 to CO and CH4, and the products flow out of the gas outlet with CO2; while FeSO4 is oxidized to Fe2(SO4)3 by photo-generated holes, Fe2(SO4)3 enters the water oxidation side through the cation membrane, and the remaining FeSO4 solution flows out of the oxidation medium outlet and circulates back to the oxidation medium inlet. On the surface of the g-C3N4 catalyst, photo-generated holes oxidize water to O2, while Fe2(SO4)3 is reduced to FeSO4 by photo-generated electrons. FeSO4 enters the CO2 reduction side through the cation membrane. The remaining Fe2(SO4)3 solution flows out of the outlet and circulates back to the inlet, and O2 is carried out of the reactor with the solution. After being reduced and oxidized, respectively, the redox medium can be recycled and regenerated by diffusing through the cation ion membrane to the opposite side due to the concentration gradient.
[0036] Although embodiments of the present application have been shown and described, it is to be understood that various modifications, substitutions, replacements and changes can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the appended claims and their equivalents.
Claims
1. A membrane module-supported three-phase interface photocatalytic reaction device, characterized in that, It includes an oxidation medium flow channel shell, a CO2 gas flow channel shell, and a reduction medium flow channel shell that are stacked and fixedly connected in sequence; the internal cavity of the oxidation medium flow channel shell constitutes the oxidation medium flow channel; the internal cavity of the CO2 gas flow channel shell constitutes the CO2 gas flow channel; and the internal cavity of the reduction medium flow channel shell constitutes the reduction medium flow channel. Both the oxidation medium flow channel shell and the CO2 gas flow channel shell have an open side, and a gas diffusion layer is provided at the open side. The gas diffusion layer is loaded with a CO2 reduction catalyst on the side facing the oxidation medium flow channel. An ion exchange membrane is provided between the oxidation medium flow channel shell and the reduction medium flow channel shell at a position corresponding to the periphery of the CO2 gas flow channel shell to enable ion exchange between the oxidation medium flow channel shell and the reduction medium flow channel shell. A water oxidation catalyst carrier membrane is provided inside the reduction medium flow channel, and a water oxidation catalyst is loaded on the water oxidation catalyst carrier membrane. Both the oxidation medium flow channel shell and the reduction medium flow channel shell are provided with light-transmitting windows at positions corresponding to the opposite sidewalls of the CO2 reduction catalyst and the water oxidation catalyst.
2. The membrane module-supported three-phase interface photocatalytic reaction device as described in claim 1, characterized in that, The oxidation medium channel and the reduction medium channel are used to fill the oxidation medium and reduction medium solutions, and the oxidation medium and the reduction medium are redox couples that can exchange ions and interconvert through the ion exchange membrane.
3. The membrane module-supported three-phase interface photocatalytic reaction device as described in claim 1, characterized in that, The CO2 gas flow channel shell is provided with a gas inlet and a gas outlet, and both the oxidation medium flow channel shell and the reduction medium flow channel shell are provided with a liquid inlet and a liquid outlet.
4. The membrane module-supported three-phase interface photocatalytic reaction device as described in claim 1, characterized in that, The gas diffusion layer has hydrophobic properties.
5. The membrane module-supported three-phase interface photocatalytic reaction device as described in claim 1, characterized in that, The CO2 gas flow channel can be a parallel flow channel, a biomimetic flow channel, a serpentine flow channel, or a spiral flow channel.
6. The membrane module-supported three-phase interface photocatalytic reaction device as described in claim 1, characterized in that, The coating shape of the CO2 reduction catalyst, the projection shape of the CO2 gas channel (6) on the gas diffusion layer (5) and the shape of the corresponding light window are the same, and the coating shape of the water oxidation catalyst is the same as the shape of the corresponding light window.
7. The membrane module-supported three-phase interface photocatalytic reaction device as described in claim 1, characterized in that, The CO2 gas flow channel shell, the oxidation medium flow channel shell, and the reduction medium flow channel shell are all made of acid and alkali resistant and high temperature resistant materials, and the light window is made of corrosion resistant and light-transmitting material.
8. The method of the membrane module-supported three-phase interface photocatalytic reaction device as described in claim 1, characterized in that, include: CO2 gas is introduced into the CO2 gas channel; an oxidation medium solution and a reduction medium solution are introduced into the oxidation medium channel and the reduction medium channel, respectively; and light is provided to the CO2 reduction catalyst and the water oxidation catalyst through the light window. In this process, on the CO2 reduction side, CO2 is photocatalytically reduced at the three-phase interface of the gas diffusion layer, while the oxidation medium is oxidized; on the water oxidation side, water is photocatalytically oxidized, while the reduction medium is reduced; the oxidized oxidation medium and the reduced reduction medium diffuse into each other through the ion exchange membrane and achieve regeneration on the opposite side, forming a cycle.
9. The method of the membrane module-supported three-phase interface photocatalytic reaction device as described in claim 8, characterized in that, The oxidizing medium is FeSO4 solution, the reducing medium is Fe2(SO4)3 solution, and the ion exchange membrane is a cation exchange membrane.