Carbon reduction device and method

Abstract

Disclosed are a carbon reduction device and method. The carbon reduction device comprises a solid adsorption layer, a heat supply plate and an electrolysis unit, wherein the solid adsorption layer is used for adsorbing carbon dioxide in the air, and the solid adsorption layer has a first side and a second side which are arranged opposite each other; the heat supply plate is arranged on the first side and is used for supplying heat for the desorption of carbon dioxide of the solid adsorption layer; and the electrolysis unit is installed on the second side and is used for subjecting carbon dioxide desorbed by the solid adsorption layer to electrolytic reduction.

Description

Carbon reduction device and method

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202311068791.7 filed in China on August 23, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the field of carbon reduction technology, and in particular to a carbon reduction device and method. Background Art

[0004] With the dual carbon goals being proposed, the capture and utilization of carbon dioxide (CO2) is gaining increasing attention. Direct air capture of CO2, unrestricted by geography and carbon source, is a highly promising capture technology. However, due to its low CO2 content, direct air capture suffers from high energy consumption and low capture efficiency, and post-capture carbon storage also presents challenges.

[0005] The storage and utilization of captured carbon are also key issues in carbon reduction. While stored CO2 does not generate revenue, converting CO2 into valuable products and utilizing them, thereby establishing a carbon cycle, is a more sustainable carbon reduction strategy. Electrochemical reduction of CO2 to organic products offers the advantages of being environmentally friendly and simple to implement. However, electrochemical carbon reduction often suffers from low conversion efficiency and selectivity. Furthermore, the presence of anion exchange membranes in aqueous electrochemical carbon reduction increases system costs.

[0006] Summary of the Invention

[0007] In view of this, one purpose of the embodiments of the present disclosure is to provide a carbon reduction device that avoids the cost of air drying by directly absorbing carbon dioxide from the air and performing in-situ electrochemical conversion; the in-situ carbon reduction conversion also enhances the concentration drive of capture, which helps to improve the capture efficiency; in addition, the direct conversion of carbon dioxide in the air into valuable products is achieved within the electrolysis unit, avoiding the cost of carbon sequestration.

[0008] Another object of the embodiments of the present disclosure is to provide a carbon reduction method.

[0009] In a first aspect, an embodiment of the present disclosure provides a carbon reduction device, comprising:

[0010] a solid adsorption layer, the solid adsorption layer being used to adsorb carbon dioxide in the air, the solid adsorption layer having a first side and a second side disposed opposite to each other;

[0011] a heating plate, the heating plate being arranged on the first side and being used to provide heat for the solid adsorption layer to desorb carbon dioxide;

[0012] An electrolysis unit is installed on the second side and is used for electrolytically reducing carbon dioxide desorbed from the solid adsorption layer.

[0013] In some embodiments, the adsorption material of the solid adsorption layer includes at least one of a solid amine adsorbent and a metal-organic framework material.

[0014] In some embodiments, the thickness of the solid adsorption layer is 0.1-1 mm.

[0015] In some embodiments, the solid adsorption layer further has an air inlet side for intake of air before carbon dioxide adsorption and an air outlet side for exhaust of air after carbon dioxide adsorption, and both the air inlet side and the air outlet side are arranged perpendicular to the first side and the second side.

[0016] In some embodiments, the air inlet side and the air outlet side are arranged opposite to each other.

[0017] In some embodiments, the air inlet side is connected to a blowing device for driving air to flow through the solid adsorption layer before carbon dioxide is adsorbed.

[0018] In some embodiments, the blowing volume of the blowing device is such that the air transfer speed in the solid adsorption layer before carbon dioxide is adsorbed is 4-10 m / s.

[0019] In some embodiments, an air inlet is provided on the air inlet side, and a gas distributor is provided at the air inlet.

[0020] In some embodiments, the solid adsorption layer is in close contact with the heating plate.

[0021] In some embodiments, the heating plate is a solar thermal collector, an electric heating plate, or a flat plate heat exchanger.

[0022] In some embodiments, the heating plate is a solar heat collecting plate, which includes a solar energy absorption material layer and a sealing layer arranged in sequence; the solar energy absorption material layer is adjacent to the solid adsorption layer.

[0023] In some embodiments, the material of the solar energy absorption material layer includes at least one of titanium oxide, aluminum oxide, boron oxide, and perovskite film.

[0024] In some embodiments, the solar energy absorption material layer has a thickness of 2-10 μm.

[0025] In some embodiments, the material of the sealing layer includes at least one of polydimethylsiloxane, polymethyl methacrylate, polycarbonate, polypropylene, and polyvinyl chloride.

[0026] In some embodiments, the sealing layer has a thickness of 1-2 mm.

[0027] In some embodiments, the electrolysis unit is a diaphragmless electrolysis cell.

[0028] In some embodiments, the electrolysis unit includes an electrolysis cell body and a cathode, an anode and an electrolyte arranged in the electrolysis cell body; the electrolysis cell body is a container with an opening on one side, and the end of the open side is sealed and connected to the second side surface of the solid adsorption layer.

[0029] In some embodiments, the liquid surface of the electrolyte contacts the second side surface of the solid adsorption layer.

[0030] In some embodiments, the electrolyte is an alkaline electrolyte.

[0031] In some embodiments, the electrolyte contains a substrate for the anode reaction.

[0032] In some embodiments, the cathode is adjacent to the solid adsorption layer, and the anode is provided on a side of the cathode away from the solid adsorption layer.

[0033] In some embodiments, the cathode is a carbon dioxide reduction reaction electrode.

[0034] In some embodiments, the anode is a metal oxide-based electrode.

[0035] In a second aspect, embodiments of the present disclosure provide a method for carbon reduction, comprising:

[0036] The solid adsorption layer absorbs carbon dioxide from the air;

[0037] The carbon dioxide adsorbed by the solid adsorption layer is desorbed after being heated;

[0038] The desorbed carbon dioxide enters the electrolytic cell and is absorbed by the electrolyte, followed by a carbon reduction reaction.

[0039] In some embodiments, the carbon reduction method further includes: adding electrolyte to the reaction system during the carbon reduction reaction.

[0040] The carbon reduction device of the embodiment of the present disclosure has at least the following beneficial effects:

[0041] 1. Use solid adsorption to capture air carbon without the need for air drying.

[0042] 2. Realize carbon dioxide consumption in the electrolysis unit, provide a driving force for gas adsorption, and synergistically enhance process efficiency.

[0043] 3. By setting up the electrolyte, cathode, anode and reaction substrate, different types of carbon reduction reactions can occur in the electrolysis unit, thereby achieving diversified application paths.

[0044] 4. Use solar collectors and other heating panels to provide desorption heat to the solid adsorption layer, which is green and environmentally friendly.

[0045] 5. The electrolysis unit adopts a diaphragm-free electrolytic cell, which can further reduce the cost of carbon reduction compared to the existing aqueous electrochemical carbon reduction with anion exchange membrane.

[0046] 6. The source of electricity for carbon reduction in the electrolysis unit can be clean energy such as photovoltaic power generation and wind power.

[0047] Additional aspects and advantages of the embodiments of the present disclosure will be given in part in the description below and in part will become apparent from the description below or will be learned through practice of the embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The above and / or additional aspects and advantages of the present disclosure will become apparent and readily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0049] FIG1 is a schematic structural diagram of a carbon reduction device according to an exemplary embodiment of the present disclosure.

[0050] FIG2 is a schematic structural diagram of a carbon reduction device according to another exemplary embodiment of the present disclosure.

[0051] Figure markings: 1-solid adsorption layer; 101-first side; 102-second side; 103-air inlet side; 104-air outlet side; 2-heating plate; 201-solar absorption material layer; 202-sealing layer; 3-electrolysis unit; 301-electrolysis cell body; 302-cathode; 303-anode; 4-blowing device; 5-sealing bonding surface. DETAILED DESCRIPTION

[0052] The embodiments of the present disclosure are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present disclosure, but should not be understood as limiting the present disclosure.

[0053] Throughout this application, the disclosure of numerical ranges includes disclosure of all values ​​within the entire range and further subdivided ranges, including endpoints and subranges given within those ranges.

[0054] In the disclosure, the raw materials, equipment, etc. involved, unless otherwise specified, are all raw materials and equipment that can be produced through commercial channels or known methods; the methods involved, unless otherwise specified, are all conventional methods.

[0055] A carbon reduction device and a carbon reduction method according to embodiments of the present disclosure will be described below with reference to the accompanying drawings.

[0056] FIG1 is a schematic structural diagram of a carbon reduction device according to an exemplary embodiment of the present disclosure.

[0057] As shown in FIG1 , the carbon reduction device according to the embodiment of the present disclosure includes a solid adsorption layer 1 , a heating plate 2 and an electrolysis unit 3 .

[0058] The solid adsorption layer 1 is used for adsorbing carbon dioxide in the air. The solid adsorption layer 1 has a first side 101 and a second side 102 that are opposite to each other.

[0059] The heating plate 2 is provided on the first side 101 and is used to provide heat for the solid adsorption layer 1 to desorb carbon dioxide.

[0060] The electrolysis unit 3 is installed on the second side 102 and is used for electrolytically reducing the carbon dioxide desorbed from the solid adsorption layer 1 .

[0061] The carbon reduction device of the embodiment of the present disclosure avoids the cost of air drying by directly absorbing carbon dioxide from the air and performing in-situ electrochemical conversion; the in-situ carbon reduction conversion also enhances the concentration drive of capture, which helps to improve the capture efficiency; in addition, the direct conversion of carbon dioxide in the air into valuable products is achieved within the electrolysis unit, avoiding the cost of carbon sequestration.

[0062] In some embodiments, the solid adsorption layer 1 is tightly attached to the heating plate 2 .

[0063] It should be noted that, in the embodiments of the present disclosure, the solid adsorption layer is tightly fitted to the heating plate, including but not limited to the first side surface of the solid adsorption layer being in direct surface contact with the surface of the heating plate merely through the placement position, the first side surface of the solid adsorption layer and the surface of the heating plate being connected by hot pressing, adhesive bonding, etc. so that the two are tightly fitted, and so on.

[0064] In some embodiments, the heating panel 2 includes but is not limited to a solar collector panel, an electric heating panel, or a flat plate heat exchanger. When a flat plate heat exchanger is selected, it can be simply a flat hollow container in which hot coal, such as hot flue gas, hot water, hot oil, etc., circulates.

[0065] As one possible example, the heating panel 2 is a solar thermal collector panel comprising a solar absorbing material layer 201 and a sealing layer 202, which are sequentially arranged. The solar absorbing material layer 201 is adjacent to the solid adsorption layer 1. Specifically, the sealing layer 202 is provided on one side of the solar absorbing material layer, and the solid adsorption layer 1 is provided on the other side. The sealing layer can isolate heat from convection, thereby improving the efficiency of carbon dioxide collection.

[0066] In some embodiments, the solar energy absorbing material layer 201 and the sealing layer 202 are connected by overlapping, hot pressing, ultrasonic welding, etc.

[0067] In some embodiments, the material of the solar energy absorption material layer 201 includes at least one of titanium oxide, aluminum oxide, boron oxide, and a perovskite film, such as a titanium oxide plate, an aluminum oxide plate, a boron oxide plate, and the like.

[0068] In some embodiments, the thickness of the solar energy absorption material layer 201 is 2-10 μm, including but not limited to 2 μm, 5 μm, 7 μm, 9 μm, or 10 μm. If the thickness of the solar energy absorption material layer is too large, the solar energy absorption rate per unit material will decrease and the heat transfer rate will decrease; if the thickness of the solar energy absorption material layer is too small, the overall heat absorption will be too low, and the carbon dioxide heating and release effect will not be effective.

[0069] In some embodiments, the material of the sealing layer 202 includes at least one of polydimethylsiloxane (PDMS), polymethyl methacrylate (PMMA), polycarbonate (PC), polypropylene (PP), and polyvinyl chloride (PVC).

[0070] In some embodiments, the thickness of the sealing layer 202 is 1-2 mm, including but not limited to 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, or 2 mm. If the sealing layer is too thin, the heat convection blocking effect will be poor, resulting in excessive heat dissipation; if the sealing layer is too thick, it will block sunlight to a certain extent, reducing the sunlight absorption rate of the absorbing material below.

[0071] In some embodiments, the adsorption material of the solid adsorption layer 1 includes, but is not limited to, at least one of a solid amine adsorbent and a metal-organic framework material. As non-limiting examples, solid amine adsorbents include, but are not limited to, at least one of polyethyleneimine (PEI)-loaded porous carbon, tetraethylenepentamine (TEPA)-loaded SBA-15 (SBA-15 is a type of mesoporous molecular sieve), and polyethyleneimine (PEI)-loaded mesoporous alumina. Metal-organic framework (MOF) materials include, but are not limited to, at least one of MOF-177, MOF-5, IRMOF-1, SIFSIX-3-Ni, SIFSIX-3-Cu, NbOFFIVE-1-Ni, and a ZIF-8 / chitosan-polyacrylamide hydrogel composite. In the embodiments of the present disclosure, the solid adsorption layer can collect carbon dioxide from the air through physical adsorption.

[0072] As a possible example, the adsorption material of the solid adsorption layer is a ZIF-8 / chitosan-polyacrylamide hydrogel composite. The synthesis method is as follows: a certain amount of chitosan (CS) is added to a 2% acetic acid solution to make the mass concentration of CS 5-15 g / L, and then a certain amount of cetyltrimethylammonium bromide (CTAB) is added, the mass of CTAB is 1 / 3 of CS, and the mixture is stirred thoroughly to obtain a CS solution. Prepare a 50 g / L solution of ammonium persulfate (APS) with a mass of 1 / 3 CS in pure water, stir evenly, and add the prepared CS solution; then add acrylic acid with a volume of 1 / 6 of the CS solution; then prepare a 12 g / L solution of N,N'-methylenebisacrylamide (BIS) with a mass of 1 / 12 CS in pure water, stir evenly, add the above solution, and stir at 70 ° C for 4 h under a vacuum nitrogen environment to prepare chitosan-polyacrylic acid gel; immerse the chitosan-polyacrylic acid gel in a methanol solution of Zn(NO3)2 and a methanol solution of 2-methylimidazole (2-MeIM) in turn, and stir at 60 ° C for more than 4 h; keep Zn 2+ The molar ratio of Zn to 2-MeIM is 1:8. 2+ The concentration was 0.6 mol / L, allowing ZIF-8 to grow in situ on the gel surface. The product was washed three times with methanol and then water, then vacuum-dried at 50°C for at least 12 hours to obtain a ZIF-8 / chitosan-polyacrylic acid hydrogel. During the synthesis process, the thickness of the gel layer before drying and forming was controlled to adjust the thickness of the solid adsorption layer within the range of the solid adsorption layer of the disclosed embodiments.

[0073] In some embodiments, the thickness of the solid adsorption layer 1 is 0.1-1 mm, including but not limited to 0.1 mm, 0.3 mm, 0.5 mm, 0.8 mm, or 1 mm. When the thickness of the solid adsorption layer is within the above range, the solid adsorption layer can achieve a high carbon dioxide adsorption rate and transfer rate while also having a high adsorption capacity, thereby fully utilizing the heat source provided by solar energy or the like on the heating panel and improving the efficiency of the carbon reduction reaction.

[0074] In some embodiments, the solid adsorption layer 1 further has an air inlet side 103 for allowing air to enter before carbon dioxide is adsorbed and an air outlet side 104 for allowing air to exit after carbon dioxide is adsorbed. Both the air inlet side 103 and the air outlet side 104 are arranged perpendicular to the first side 101 and the second side 102 .

[0075] It is understandable that as long as the air inlet side 103 and the air outlet side 104 are both arranged perpendicular to the first side 101 and the second side 102, the relative positions of the air inlet side and the air outlet side are not limited, and can be arranged adjacently, oppositely, etc.

[0076] However, in order to extend the flow path of air in the solid adsorption layer and ensure that as much carbon dioxide in the air as possible is adsorbed by the solid adsorption layer, as a possible example, the air inlet side 103 and the air outlet side 104 are arranged relative to each other.

[0077] It should be noted that in the embodiments of the present disclosure, the specific locations of the first side, second side, air inlet side, and air outlet side are not limited, as long as they conform to the defined positional relationships among them. For example, as shown in FIG1 , when the carbon reduction device is placed horizontally, the first side 101 refers to the upper side of the solid adsorption layer 1, the second side 102 refers to the lower side of the solid adsorption layer 1, the air inlet side 103 refers to the left side of the solid adsorption layer 1, and the air outlet side 104 refers to the right side of the solid adsorption layer 1.

[0078] In the embodiments of the present disclosure, the structure of the solid adsorption layer can exist in at least one of the following ways:

[0079] The first type: the solid adsorption layer is a material layer composed only of the adsorption material itself;

[0080] The second method is to provide a shell layer for covering the solid adsorption layer on the portion of the solid adsorption layer other than the first side, the second side, the air inlet side, and the air outlet side (for example, when the solid adsorption layer is in the shape of a rectangular parallelepiped, with the first side being the upper side, the second side being the lower side, the air inlet side being the left side, and the air outlet side being the right side, the shell layer covers the front and rear sides of the solid adsorption layer);

[0081] The third type: a shell layer for covering the solid adsorption layer is provided on all parts of the solid adsorption layer except the first side and the second side (for example, when the solid adsorption layer is in the shape of a rectangle, and the first side is the upper side and the second side is the lower side, the shell layer covers the entire side wall of the solid adsorption layer - the air inlet side (front side), the air outlet side (rear side), the left side and the right side), and the air inlet side 103 and the air outlet side 104 are respectively provided with an air inlet and an air outlet.

[0082] All three methods achieve the goal of having the solid adsorption layer adsorb carbon dioxide from the air and then discharging it from the solid adsorption layer. Compared to the first method, the second and third methods can better ensure that air enters from the air inlet side and exits from the air outlet side. Furthermore, the second method has a more uniform distribution of air entering the solid adsorption layer, while the third method, due to the provision of an air inlet and an air outlet, has slightly less uniform distribution of air entering the solid adsorption layer.

[0083] Therefore, as shown in FIG2 , in some embodiments, in order to ensure that air can better enter the solid adsorption layer from the air inlet side before carbon dioxide is adsorbed, and that air can better exit the solid adsorption layer from the air outlet side after carbon dioxide is adsorbed, for the solid adsorption layer in the above three methods in the embodiments of the present disclosure, a blower device 4 for forcing air to flow through the solid adsorption layer 1 before carbon dioxide is adsorbed can be connected to the air inlet side 103. In this way, on the one hand, the blower device drives the air to flow from the air inlet side to the air outlet side through the solid adsorption layer, adsorbing carbon dioxide therein, and the air contacts each part of the solid adsorption layer relatively evenly; on the other hand, by setting the blowing volume of the blower device, the boundary layer resistance of heat transfer can be eliminated, thereby increasing the transfer speed of carbon dioxide to the electrolysis unit; in addition, the setting of the blower device can also provide sufficient carbon dioxide adsorption substrate for the solid adsorption layer.

[0084] As non-limiting examples, the blowing device 4 includes, but is not limited to, one of a centrifugal blower, a positive displacement blower, an axial flow blower, and the like.

[0085] In some embodiments, the blowing volume of the blowing device 4 is such that the air transfer speed of the air in the solid adsorption layer 1 before the carbon dioxide is adsorbed is 4-10 m / s, including but not limited to 4 m / s, 6 m / s, 8 m / s or 10 m / s, etc. The blowing volume of the blowing device is such that the air transfer speed in the solid adsorption layer before the carbon dioxide is adsorbed is within the above-mentioned range, which can eliminate the boundary layer resistance of solar heat transfer when the heating plate is a solar collector, and increase the transfer speed of carbon dioxide to the electrolysis unit; if the transfer speed is too low, the improvement effect of ensuring that air enters from the air inlet side and is discharged from the air outlet side is not obvious; if the transfer speed is too high, the speed of air flowing through the solid adsorption layer is too fast, and some carbon dioxide may be discharged with the air before being adsorbed, thereby reducing the content of carbon dioxide participating in carbon reduction, reducing the amount of recovered products, and causing carbon emissions.

[0086] As a possible example, when the third form mentioned above is adopted - a shell layer for covering the solid adsorption layer is provided on all parts of the solid adsorption layer except the first side and the second side, an air inlet and an air outlet are provided on the air inlet side 103 and the air outlet side 104 respectively, or when the air inlet is connected to the blowing device 4 at the same time, a gas distributor for evenly distributing the air from the air inlet on the air inlet side is provided at the air inlet.

[0087] It should be noted that the electrolysis unit in the carbon reduction device of the present disclosure can be a conventional electrolysis cell with a diaphragm or a diaphragm-free electrolysis cell. However, to reduce costs, in some embodiments, the electrolysis unit is a diaphragm-free electrolysis cell, and the structure of the diaphragm-free electrolysis cell is not limited.

[0088] As a non-limiting example, the electrolytic unit 3 of the embodiment of the present disclosure adopts a diaphragmless electrolytic cell, which includes an electrolytic cell body 301 and a cathode 302, an anode 303 and an electrolyte arranged in the electrolytic cell body 301; the electrolytic cell body 301 is a container with an opening on one side, and the end of the open side is sealed and connected to the surface of the second side 102 of the solid adsorption layer 1, and the contact part between the two can become a sealing fitting surface 5 (as shown in Figures 1 and 2).

[0089] In some embodiments, the material of the electrolytic cell body 301 includes but is not limited to stainless steel, transparent or translucent plastic, etc., wherein the transparent or translucent plastic includes but is not limited to polytetrafluoroethylene (PTFE), polymethyl methacrylate (PMMA, commonly known as acrylic or organic glass), etc.

[0090] In some embodiments, the surface of the electrolyte contacts the second side 102 of the solid adsorption layer 1. This design is intended to allow the alkaline electrolyte to absorb carbon dioxide removed from the second side 102, thereby enhancing the mass transfer of carbon dioxide from the solid adsorption layer to the electrolyte, thereby enhancing mass transfer within the solid adsorption layer.

[0091] In some embodiments, the electrolyte is an alkaline electrolyte, such as a 20-30 wt % KOH solution.

[0092] In some embodiments, the electrolyte contains, in addition to the alkaline electrolyte, a substrate for the anodic reaction. The substrate for the anodic reaction includes, but is not limited to, at least one of ethylene glycol, methanol, and heteroaromatic hydrocarbons (bipyridine, tripyridine, pyrimidine, pyrazine, quinoline, etc.). In the embodiments of the present disclosure, different types of carbon reduction reactions can be generated in the electrolytic cell by designing the reaction process and the reaction substrate.

[0093] In some embodiments, the content of the anode reaction substrate in the electrolyte is 0.1-0.5 M, including but not limited to 0.1 M, 0.2 M, 0.3 M, 0.4 M or 0.5 M.

[0094] In some embodiments, the cathode 302 is adjacent to the solid adsorption layer 1, and the anode 303 is provided on the side of the cathode 302 away from the solid adsorption layer 1. It should be noted that in the embodiments of the present disclosure, the closer the cathode is to the solid adsorption layer, the better. The reason is that the proximity of the cathode to the solid adsorption layer can shorten the mass transfer path of carbon dioxide in the electrolyte, accelerate the process of carbon dioxide transfer to the cathode surface, and thus enhance the cathode carbon dioxide reduction reaction. The spacing between the anode and the cathode is not limited, as long as the surface of the anode away from the solid adsorption layer does not contact the electrolytic cell body.

[0095] In some embodiments, the cathode 302 is a carbon dioxide reduction reaction electrode, including but not limited to one of a Pb electrode, a Hg electrode, a Tl electrode, an In electrode, a Sn electrode, a Cd electrode, a Ni electrode, and a Cu electrode.

[0096] In some embodiments, the anode 303 is a metal oxide-based electrode, including but not limited to an Ir oxide electrode, a Ru oxide electrode, a composite nickel-based metal oxide electrode, and the like.

[0097] In some embodiments, the specific installation method of cathode 302 and anode 303 in electrolytic cell body 301 is not limited, including but not limited to solid installation using a bracket, clamping and fixing through grooves provided on the side wall of the electrolytic cell body, etc.

[0098] The method for performing carbon reduction using the carbon reduction device of the embodiment of the present disclosure (i.e., the operating method of the carbon reduction device of the embodiment of the present disclosure) comprises the following steps:

[0099] S101. The solid adsorption layer 1 adsorbs carbon dioxide from the air.

[0100] S102, the carbon dioxide adsorbed by the solid adsorption layer 1 is desorbed after being heated.

[0101] The carbon dioxide adsorbed by the solid adsorption layer is desorbed from the solid adsorption layer under the heating effect of the heating plate.

[0102] In some embodiments, the temperature for thermal desorption of carbon dioxide adsorbed by the solid adsorption layer is 25-60°C, including but not limited to 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C or 60°C.

[0103] It should be noted that in the embodiments disclosed herein, the solid adsorption layer simultaneously adsorbs and desorbs carbon dioxide from the air under heat. Because carbon dioxide is continuously consumed below the adsorption layer near the electrolytic cell, the resulting concentration gradient perpendicular to the adsorption layer provides a high carbon dioxide mass transfer driver, maintaining a dynamic equilibrium for carbon dioxide adsorption, desorption, and transfer. In steady state, uniform adsorption, desorption, and transfer rates are achieved within an appropriate temperature range, providing the electrolytic cell with ample reaction substrate.

[0104] S103. The desorbed carbon dioxide enters the electrolytic cell and is absorbed by the electrolyte, followed by a carbon reduction reaction.

[0105] The carbon dioxide is transferred from the side where the solid adsorption layer is located to the side where the electrolysis unit is located (for example, when the heating plate, the solid adsorption layer, and the electrolysis unit are arranged in order from top to bottom, that is, the desorbed carbon dioxide is transferred from top to bottom). When it contacts the concentrated alkaline solution (for example, the 20-30 wt% KOH solution) on the surface of the solid adsorption layer away from the heating plate (that is, the second side 102), it is absorbed by the concentrated alkaline solution. The carbon dioxide reacts on the cathode surface, for example: CO2 + H2O + 2e - ——>HCOOH+OH -

[0106] On the anode surface, the anode reaction substrate undergoes oxidation reaction to generate the same product, such as: 6OH - +C2H4(OH)2——>2HCOOH+4H2O+2e - .

[0107] In some embodiments, the process conditions of the carbon reduction reaction are: reaction voltage of 1-5V, current density of 10-500mA / cm 2 , the reaction temperature is 25-80℃.

[0108] As a non-limiting example, the reaction voltage of the carbon reduction reaction includes but is not limited to 1V, 2V, 3V, 4V or 5V, and the current density includes but is not limited to 10mA / cm 2 , 50mA / cm 2 , 100mA / cm 2 , 200mA / cm 2 、300mA / cm 2 、 400mA / cm 2 or 500mA / cm 2 The reaction temperature includes but is not limited to 25°C, 30°C, 40°C, 50°C, 60°C, 70°C or 80°C.

[0109] In some embodiments, to ensure reaction continuity, the carbon reduction method further includes the step of replenishing electrolyte into the reaction system during the carbon reduction reaction. That is, the carbon reduction method further includes the step of replenishing alkaline solution and anode reaction substrate into the reaction system during the carbon reduction reaction.

[0110] Certain features of the present technology are further illustrated in the following non-limiting examples.

[0111] As shown in FIG2 , the carbon reduction device of this embodiment includes a solid adsorption layer 1 , a heating plate 2 , and an electrolysis unit 3 , which are sequentially arranged from top to bottom.

[0112] Solid adsorption layer 1 is used to adsorb carbon dioxide from the air. It is rectangular in shape, with its upper surface (the surface of the first side 101) tightly attached to a heating plate 2, which provides heat for desorbing carbon dioxide from the solid adsorption layer 1. This embodiment utilizes a solar collector. The lower surface (the surface of the second side 102) of the solid adsorption layer 1 is sealed to an electrolysis unit 3, which is used to electrolytically reduce carbon dioxide desorbed from the solid adsorption layer 1. This embodiment utilizes a diaphragmless electrolytic cell. The left side of the solid adsorption layer 1 is the air inlet side 103, and the right side is the air outlet side 104.

[0113] A blower 4 is provided on the left side of the solid adsorption layer 1 to force air through the solid adsorption layer 1 before carbon dioxide is adsorbed. The exhaust port of the blower 4 faces the middle of the left side of the solid adsorption layer 1, with a spacing of 1 cm between the two. The blower 4 utilizes a positive displacement blower. This ensures that, on the one hand, the blower forces air to flow from the air inlet to the air outlet through the solid adsorption layer, adsorbing carbon dioxide therein, while also ensuring relatively uniform contact between the air and all parts of the solid adsorption layer. Furthermore, by adjusting the air volume of the blower, boundary layer resistance to solar heat transfer can be eliminated, increasing the transfer rate of carbon dioxide to the electrolysis unit. Furthermore, the blower also provides the solid adsorption layer with sufficient carbon dioxide adsorption substrate.

[0114] The solid adsorption layer 1 is a ZIF-8 / chitosan-polyacrylamide hydrogel composite, and its synthesis method is as follows:

[0115] A certain mass (e.g., 12 g) of chitosan (CS) is added to a 2 wt% acetic acid solution to make the mass concentration of CS 5-15 g / L, and then a certain amount of cetyltrimethylammonium bromide (CTAB) is added, the mass of CTAB being 1 / 3 of that of CS, and the mixture is stirred thoroughly to obtain a CS solution. Prepare a 50 g / L solution of ammonium persulfate (APS) with a mass of 1 / 3 CS in pure water, stir evenly, and add the prepared CS solution; then add acrylic acid with a volume of 1 / 6 of the CS solution to obtain a mixed solution; then prepare a 12 g / L solution of N,N'-methylenebisacrylamide (BIS) with a mass of 1 / 12 CS in pure water, stir evenly, add the above mixed solution, and stir at 70 ° C for 4 h under a vacuum nitrogen environment to prepare chitosan-polyacrylic acid gel; immerse the chitosan-polyacrylic acid gel in a methanol solution of Zn(NO3)2 and a methanol solution of 2-methylimidazole (2-MeIM) in turn, and stir at 60 ° C for more than 4 h (for example, 6 h); keep Zn 2+ The molar ratio of Zn to 2-MeIM is 1:8. 2+The concentration is 0.6 mol / L, so that ZIF-8 grows in situ on the surface of the gel; the product is washed three times with methanol and deionized water respectively, and vacuum dried at 50°C for more than 12 hours (for example, 15 hours) to obtain ZIF-8 / chitosan-polyacrylic acid hydrogel. During the synthesis process, the thickness of the solid adsorption layer is regulated by controlling the thickness of the gel layer before drying and molding to be within the thickness range of the solid adsorption layer of the embodiment of the present disclosure. The thickness of the obtained gel is 0.2 mm. The adsorption rate of carbon dioxide by the solid adsorption layer is 0.12 mmol (CO2) / g (adsorbent) / min, and when the solar power reaches 2 W / cm 2 When the above conditions are met, when the average residence time of air passing through the solid adsorption layer by the blowing device reaches 0.5h and the surface flow velocity reaches 4m / s, a carbon dioxide absorption rate of more than 80% and a carbon dioxide release rate of 0.1mmol(CO2) / g(adsorbent) / min can be obtained.

[0116] As previously mentioned, heating panel 2 utilizes a solar thermal collector, comprising a solar absorber layer 201 and a sealing layer 202, arranged sequentially from top to bottom. The lower surface of the solar absorber layer 201 is in close contact with the lower surface of the solid adsorption layer 1. The sealing layer, which isolates heat dissipation through convection and improves carbon dioxide collection efficiency, is bonded to the solar absorber layer 201 via hot pressing. The solar absorber layer 201 is a titanium oxide plate with a thickness of 5 μm. The sealing layer 202 is made of polydimethylsiloxane (PDMS) and is 1.5 mm thick.

[0117] As described above, the electrolysis unit 3 adopts a diaphragmless electrolytic cell, which includes an electrolytic cell body 301 and a cathode 302, an anode 303 and an electrolyte arranged in the electrolytic cell body 301; the electrolytic cell body 301 is a rectangular container with an open top (completely open), and the top of the electrolytic cell body is sealed and connected to the lower surface of the solid adsorption layer 1 at a position facing the side wall of the electrolytic cell body, and the contact portion between the two can become a sealing fitting surface 5 (as shown in Figure 2).

[0118] The electrolytic cell body 301 is made of polytetrafluoroethylene (PTFE) and is equipped with an electrolyte replenishment port for replenishing the electrolyte (alkaline solution and anode reaction products) and a product collection port. The electrolyte consists of a 25 wt% KOH solution and ethylene glycol, the anode reaction substrate. The content of ethylene glycol in the electrolyte is 0.1-0.5 M (e.g., 0.3 M). The electrolyte surface contacts the lower surface of the solid adsorption layer 1.

[0119] Both the cathode 302 and anode 303 are arranged parallel to the solid adsorption layer 1 and the heating plate 2, with the cathode 302 positioned above the anode 303. The cathode 302 is adjacent to the solid adsorption layer 1, with a spacing of 1 mm between the two. A gap is left between the lower surface of the anode 303 and the bottom of the electrolytic cell body 301, and the gap between the anode 303 and cathode 302 is 1-5 cm (e.g., 3 cm). The front and rear sides of both the anode 303 and cathode 302 are fixedly connected to slots on the front and rear walls of the electrolytic cell body 301, and the left and right sides of both the anode 303 and cathode 302 are spaced from the left and right walls of the electrolytic cell body 301. The cathode 302 is a Sn electrode, and the anode 303 is an Ir oxide electrode.

[0120] The working method of the carbon reduction device of this embodiment (i.e., the carbon reduction method) is:

[0121] Solid adsorption layer 1 absorbs carbon dioxide from the air. Under the heating effect of the solar collector plate 2, carbon dioxide desorbs from solid adsorption layer 1 and transfers from top to bottom. When it contacts the concentrated alkaline solution (25wt% KOH solution) on the lower surface of solid adsorption layer 1, it is absorbed by the concentrated alkaline solution. Carbon dioxide reacts on the cathode surface, for example: CO2 + H2O + 2e - ——>HCOOH+OH -

[0122] On the anode surface, the anode reaction substrate undergoes oxidation reaction to generate the same product, such as: 6OH - +C2H4(OH)2——>2HCOOH+4H2O+2e - .

[0123] The process conditions for the carbon reduction reaction are: a reaction voltage of 1.8-2.2 V (e.g., 2 V), a current density of 10-50 mA / cm 2 (For example, 30 mA / cm 2 ), the reaction temperature was 25°C.

[0124] During the reaction, 25 wt% KOH solution and ethylene glycol, the anode reaction substrate, need to be added to the system. The replenishment standard is: replenish the consumption of hydroxide ions and ethylene glycol to maintain the KOH and ethylene glycol concentrations within the optimal concentration range during the continuous reaction.

[0125] It should be noted that different types of carbon reduction reactions can occur in the electrolysis unit through the design of reactants and reaction processes. In addition to the formic acid production mentioned above, at least the following reactions can also occur in the diaphragmless electrolysis cell:

[0126] (1) Production of dimethyl carbonate: Refer to Redox-neutral electrochemical conversion of CO2 to dimethyl carbonate.

[0127] (2) Pharmaceuticals: References: Electrochemical reactor dictates site selectivity in N-heteroarene carboxylations.

[0128] In summary, the carbon reduction device and method of the embodiments of the present disclosure avoid the cost of air drying by directly absorbing carbon dioxide from the air and performing in-situ electrochemical conversion; the in-situ carbon reduction conversion also enhances the concentration drive of capture, which helps to improve the capture efficiency; in addition, the direct conversion of carbon dioxide in the air into valuable products is achieved within the electrolysis unit, avoiding the cost of carbon sequestration.

[0129] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present disclosure.

[0130] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. Throughout the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0131] In this disclosure, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or communication between them; direct connections or indirect connections through an intermediate medium; and internal communication between two elements or interaction between two elements, unless otherwise expressly limited. Those skilled in the art will understand the specific meanings of the above terms in this disclosure based on specific circumstances.

[0132] In the present disclosure, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0133] In the present disclosure, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0134] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

[0135] All embodiments of the present disclosure may be implemented individually or in combination with other embodiments, and are all considered to be within the scope of protection claimed by the present disclosure.

Claims

1. A carbon reduction device, comprising: A solid adsorption layer, the solid adsorption layer is used to adsorb carbon dioxide in the air, and the solid adsorption layer has a first side and a second side arranged opposite to each other; A heating plate, the heating plate is arranged on the first side and is used to provide heat for the solid adsorption layer to desorb carbon dioxide; An electrolysis unit is installed on the second side and is used for electrolytic reduction of carbon dioxide desorbed from the solid adsorption layer.

2. The carbon reduction device according to claim 1, wherein: The adsorption material of the solid adsorption layer includes at least one of a solid amine adsorbent and a metal-organic framework material; And / or, the thickness of the solid adsorption layer is 0.1-1 mm.

3. The carbon reduction device according to claim 1 or 2, wherein: The solid adsorption layer also has an air inlet side for air before carbon dioxide is adsorbed and an air outlet side for air after carbon dioxide is adsorbed. The air inlet side and the air outlet side are both arranged perpendicular to the first side and the second side.

4. The carbon reduction device according to claim 3, wherein: The air inlet side and the air outlet side are arranged opposite to each other; And / or, the air inlet side is connected to a blowing device for driving air to forcefully flow through the solid adsorption layer before the carbon dioxide is adsorbed.

5. The carbon reduction device according to claim 4, wherein: The blowing amount of the blowing device is such that the air transfer speed in the solid adsorption layer before the carbon dioxide is adsorbed is 4-10 m / s; And / or, the air inlet side is provided with an air inlet, and a gas distributor is provided at the air inlet.

6. The carbon reduction device according to any one of claims 1 to 5, wherein: The solid adsorption layer is closely attached to the heating plate; And / or, the heating plate is one of a solar collector plate, an electric heating plate or a flat plate heat exchanger.

7. The carbon reduction device according to claim 6, characterized in that: The heating plate is a solar heat collecting plate, which comprises a solar energy absorption material layer and a sealing layer which are arranged in sequence; the solar energy absorption material layer is adjacent to the solid adsorption layer.

8. The carbon reduction device according to claim 7, wherein: The material of the solar energy absorption material layer includes at least one of titanium oxide, aluminum oxide, boron oxide, and perovskite film; and / or, the thickness of the solar energy absorbing material layer is 2-10 μm; And / or, the material of the sealing layer includes at least one of polydimethylsiloxane, polymethyl methacrylate, polycarbonate, polypropylene, and polyvinyl chloride; And / or, the sealing layer has a thickness of 1-2 mm.

9. The carbon reduction device according to any one of claims 1 to 8, wherein: The electrolysis unit is a diaphragmless electrolysis cell; And / or, the electrolysis unit includes an electrolytic cell body and a cathode, an anode and an electrolyte arranged in the electrolytic cell body; the electrolytic cell body is a container with an opening on one side, and the end of the open side is sealed and connected to the second side surface of the solid adsorption layer.

10. The carbon reduction device according to claim 9, wherein: The liquid surface of the electrolyte contacts the second side surface of the solid adsorption layer; And / or, the electrolyte is an alkaline electrolyte; and / or, the electrolyte contains a substrate for an anode reaction; And / or, the cathode is adjacent to the solid adsorption layer, and the anode is arranged on the side of the cathode away from the solid adsorption layer; And / or, the cathode is a carbon dioxide reduction reaction electrode; And / or, the anode is a metal oxide based electrode.

11. A method for carbon reduction using the carbon reduction device according to any one of claims 1 to 10, comprising: The solid adsorption layer absorbs carbon dioxide from the air; The carbon dioxide adsorbed by the solid adsorption layer is desorbed after being heated; The desorbed carbon dioxide enters the electrolytic cell and is absorbed by the electrolyte, followed by a carbon reduction reaction.

12. The carbon reduction method according to claim 11, wherein: The carbon reduction method further comprises: During the carbon reduction reaction, an electrolyte is added to the reaction system.

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