CO2 thermosensitive crystallization photo-thermal regeneration power generation system and method

Abstract

The invention discloses a CO2 thermosensitive crystallization photo-thermal regeneration power generation system and method, and belongs to the field of photo-thermal power generation, and the method comprises the steps: enabling CO2 in carbonic acid group guanidine salt solid crystals to be desorbed and circularly absorbed and regenerated in an alkaline absorbent by utilizing the property that guanidine salt and carbonate are crystallized after being combined; therefore, proton concentration potential is formed at the cathode and the anode of the system for external discharge, thereby realizing conversion from photo-thermal energy to electric energy. The device can adapt to heat sources of different grades at the same time, and efficient power generation can be achieved. In addition, the system can also be applied to CO2 with different concentrations, and integration of CO2 capture and heat energy power generation is achieved.

Description

Technical Field

[0001] The present invention relates to the field of photothermal power generation, and more specifically, to a CO2 thermosensitive crystal photothermal regeneration power generation system and method. Background Art

[0002] Solar energy represents a huge, yet to be fully developed renewable energy source. In terms of available quantities, solar energy is the most promising source of renewable energy. The average solar radiation received on Earth is about 162,000 TW, which is four orders of magnitude greater than the current global total energy demand, and only a small part of this energy is used to generate electricity. There are many different ways to convert solar energy into electrical energy. The two most commonly used methods are solar photovoltaic conversion (PV) and solar thermal conversion. Solar photovoltaic conversion uses the photovoltaic effect of semiconductor materials to directly convert solar radiation into electrical energy. Solar thermal conversion power generation uses solar collectors to collect solar radiation and convert it into heat, and then directly uses the heat to generate electricity.

[0003] At present, there are mainly two types of solar thermal power generation technologies. One is the light energy-heat energy-mechanical energy-electrical energy conversion based on the principle of thermal power generation (concentrated solar power generation technology, CSP), and the other is solar semiconductor temperature difference power generation based on the solid Seebeck effect.

[0004] Concentrated solar thermal power generation technology is the most promising form of technology for commercial use today. According to different ways of focusing, concentrated solar thermal power generation can be further divided into two major systems: electric focusing and line focusing. Among them, the point focusing system mainly includes tower solar thermal power generation and dish solar thermal power generation; the line focusing system mainly includes trough solar thermal power generation and linear Fresnel solar thermal power generation. At the same time, many new CSP-like systems are being developed. These systems also achieve solar thermal power generation through the conversion of four energies: light energy-heat energy-mechanical energy-electricity, but the conversion of light-heat and heat-mechanical energy is more diverse. Representative systems include the following: solar chimney power generation that uses air to be heated up under a ceiling made of glass or other transparent materials to drive a turbine generator to generate electricity; solar pool power generation that uses solar energy to rapidly increase the temperature of the bottom of the salt water pool to drive a low-boiling-point working fluid to drive a steam turbine to rotate and generate electricity; solar thermoacoustic power generation system that uses the thermoacoustic effect to make gas (helium) vibrate under the action of a temperature gradient to drive a linear AC generator to generate electricity, etc.

[0005] The heat source generated by solar radiation can also be coupled to a thermoelectric generator TEG to generate electricity. TEG mainly relies on the Seebeck effect in solid materials to convert thermal energy into electrical energy. In a solar thermal power generation system, a device that replaces a traditional mechanical heat engine with a TEG is called a solar thermal generator (STEG). A solar thermal electric generator (STEG) is a system designed to convert solar energy into electrical energy through a thermoelectric generator (TEG). From an energy perspective, in a STEG, solar energy is first converted into thermal energy and then directly converted into electrical energy. The simplest STEG requires only three components: a solar collector, a thermoelectric generator (TEG), and a heat sink. STEG is formed by placing TEG between a solar absorber and a heat sink. The solar absorber absorbs solar radiation, causing the temperature to rise, which is connected to one side of the TEG, while the heat sink side remains at a constant temperature. This allows the TEG to obtain a temperature gradient, which in turn forms a voltage gradient under the Seebeck effect. If the TEG is connected to a load, a thermoelectric current is generated to drive the load to operate, ultimately achieving solar thermal power generation. At present, research on STEG systems is still mainly focused on:

[0006] 1. Increase the temperature difference between the hot and cold ends T h -T c (Improved solar collectors and radiators);

[0007] 2. Improve the average thermoelectric quality factor ZT value of thermoelectric materials (improve thermoelectric generators). However, due to the low energy density of solar radiation, the temperature difference between the two ends of the TEG system is small, the TEG system itself has a low Seebeck coefficient, and the thermal conductivity and electrical conductivity are difficult to control, so the application of the STEG system is still not ideal.

[0008] Thermoelectrochemical cycle batteries based on entropy change of liquid-based systems are expected to show great advantages in the field of solar thermal power generation. Summary of the invention

[0009] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a CO2 thermosensitive crystallization photothermal regeneration power generation system and method, which realizes the conversion of photothermal energy into electrical energy and can be adapted to heat sources of different grades to achieve efficient power generation. In addition, the system can also be applied to CO2 of different concentrations to achieve the integration of CO2 capture and thermal power generation.

[0010] The object of the present invention is achieved through the following solutions:

[0011] A CO2 thermosensitive crystallization photothermal regeneration power generation system comprises: a load, a battery system, a CO2 desorption tank, a CO2 buffer tank and a CO2 absorption tank, wherein the battery system comprises a battery anode gas chamber, a battery anode, a battery anode region, a cation exchange membrane, a battery cathode region, a battery cathode, a battery cathode gas chamber and a battery system; the load is connected to the battery anode and the battery cathode of the battery system, and is used to receive and detect the electric energy output by the battery; the battery anode gas chamber is connected to the battery cathode gas chamber flow channel, and is used to realize the hydrogen circulation system of the battery; during the reaction process, a hydrogen evolution reaction occurs on the battery cathode to decompose water to produce H2, and the gas is transported to the anode region through a one-way pipeline, and an electrochemical hydrogen oxidation reaction occurs on the battery anode, and H2 loses electrons to generate H + The battery anode and cathode are separated by a cation exchange membrane. Electrochemical hydrogen oxidation occurs at the battery anode, and H2 loses electrons to generate H + , which reduces the alkalinity of the anode area; under the action of the electric field, the cations in the anode area of ​​the battery reach the cathode area of ​​the battery through the cation exchange membrane to ensure charge balance; the anode liquid after the reaction is CO3 2- / HCO3 - , it enters the CO2 absorption tank to absorb the CO2 desorbed by photothermal desorption, and converts it into HCO3 - Realize cycle regeneration, regenerated HCO3 - The solution circulates to the cathode area as the cathode reaction raw material. The reaction equation is as follows:

[0012] Anode reaction: H2→2H + +2e -

[0013] Anode reaction: 2H + +2CO3 2- →2HCO3 -

[0014] CO2 absorption tank reaction: CO3 2- +CO2+H2O→2HCO3 -

[0015] The cathode of the battery is a hydrogen evolution electrode, which undergoes an electrochemical reduction reaction to decompose water to produce H2 and OH - , so that the cathode liquid alkalinity increases and is used to absorb the circulating CO2 desorbed by photothermal desorption to generate bicarbonate solution. The reaction equation is as follows:

[0016] Cathode reaction: 2H2O+2e - →H2+2OH -

[0017] Cathode zone reaction: 2OH - +2CO2→2HCO3 -

[0018] In the cathode zone, salts recycled from the CO2 photothermal desorption tank are crystallized with the cathode liquid after the reaction, and the salts include guanidine salt G;

[0019] Guanidine salt G from HCO3 - Grab a proton H + Combined with a HCO3 - G-H2CO3 crystals are formed and precipitated, and the alkaline absorbent CO3 is regenerated through this process 2- The solution is transported to the anode area for recycling, and the remaining guanidine salt after desorption of CO2 is recycled back to the cathode area for use; the guanidine salt G and HCO3 - The crystallization reaction is as follows:

[0020] Guanidine-carbonic acid crystallization reaction: G+2HCO3 - →G-H2CO3↓+CO3 2-

[0021] The G-H2CO3 crystals precipitated from the cathode liquid are transported to the CO2 desorption tank, where they are heated and mixed by photothermal energy to release CO2. The released CO2 is transported to the CO2 buffer tank for short-term storage, and then divided into two streams and respectively passed into the CO2 absorption tank for regeneration of the cathode raw liquid and into the cathode area for acidification of the cathode liquid to reduce the pH value. The reaction formula is as follows:

[0022] CO2 desorption tank reaction: G-H2CO3→G+H2O+CO2↑

[0023] CO2 is desorbed and released under light and heat, and the guanidine salt G is recycled.

[0024] Furthermore, the battery anode includes a platinum electrode and a platinum-plated nickel mesh.

[0025] Furthermore, the CO2 absorption tank also serves as an anode liquid buffer tank.

[0026] Furthermore, the battery cathode includes a platinum electrode and a platinum-plated nickel mesh.

[0027] A CO2 thermosensitive crystallization photothermal regeneration power generation system, in which the carbonate solution in the CO2 thermosensitive crystallization photothermal regeneration power generation system as described in any of the above items is used as a CO2 absorbent to adapt to different types of cations, wherein the carbonate solution can be replaced by any one of KOH, NaOH, ammonia water, monoethanolamine, ethylenediamine, triethanolamine, and piperazine.

[0028] A CO2 thermosensitive crystal photothermal regeneration power generation system, wherein the electrode reactions used in the CO2 thermosensitive crystal photothermal regeneration power generation system as described in any of the above items are hydrogen evolution reaction HER and oxygen oxidation reaction HOR, and the hydrogen evolution reaction HER and oxygen oxidation reaction HOR can be replaced by oxygen evolution reaction OER and oxygen reduction reaction ORR.

[0029] A CO2 thermosensitive crystal photothermal regeneration power generation system, the electrode reaction used in the CO2 thermosensitive crystal photothermal regeneration power generation system as described in any of the above items can be replaced by a proton H + Any electrochemical reaction that transfers.

[0030] A CO2 thermosensitive crystal photothermal regeneration power generation method realizes the conversion of photothermal energy into stable electrical energy output through hydrogen circulation reaction, guanidine salt-CO2 crystal thermosensitive regeneration cycle and fluid pumping cycle, and specifically includes the following sub-steps:

[0031] By utilizing the crystallization properties of guanidine salts combined with carbonates, the CO2 in the solid crystals is desorbed by photothermal drive and cyclically absorbed and regenerated in the alkaline absorbent, thereby forming a proton concentration difference potential at the anode and cathode of the system and discharging it to the outside, thereby realizing the conversion of photothermal energy into electrical energy.

[0032] Furthermore, the crystallization property of guanidine salt combined with carbonate is utilized to desorb CO2 in the solid crystal driven by light and heat and regenerate it by cyclic absorption in the alkaline absorbent, thereby forming a proton concentration difference potential at the anode and cathode of the system and discharging it externally, thereby realizing the conversion of light and heat energy into electrical energy, which specifically includes the following sub-steps:

[0033] First, CO2 absorbent is added to the anode region to increase the pH value of the solution, and cathode solute is added to the cathode region and CO2 is introduced to maintain the pH value. The positive and negative electrodes of the system are separated by a cation exchange membrane. At this time, there is a proton concentration difference ΔpH between the positive and negative electrodes of the system, which generates a potential difference. In addition, by circulating hydrogen as a mass-electrode coupling agent to construct a redox couple and a proton carrier, the anode undergoes H2 oxidation reaction HOR, loses electrons and releases protons H + , acidifying the solution and neutralizing the alkalinity of the anode area; the cathode undergoes a hydrogen evolution reaction (HER) to obtain electrons and extract H from the solution + , alkalize the solution, and the generated H2 is then passed into the anode for recycling. During the discharge process, the cation exchange membrane separates the positive and negative electrodes and allows the cations in the anode area to pass through the membrane to the cathode area to maintain the charge balance of the system; the driving force of this process comes from the ΔpH of the positive and negative electrodes, and the sign of discharge termination is ΔpH of 0;

[0034] After the discharge is completed, the anode region is filled with protons H + The continuous generation of CO3 2- / HCO3 -The solution is then fed with the CO2 desorbed from the cathode to convert it into HCO3 - The solution is circulated to the cathode for standby use; the desorbed CO2 is introduced into the cathode during discharge, and the cathode solution is HCO3 when the discharge ends. - , adding a salt to the solution, wherein the salt comprises a guanidine salt G;

[0035] Guanidine salt G makes part of HCO3 - Transformed into G-H2CO3 crystal precipitate, the filtered solution CO3 - The solution is returned to the anode for standby use, while the crystallized part uses photothermal to drive CO2 desorption. The desorbed CO2 is returned to the cathode solution and the anode solution after the reaction, and the guanidine salt G is recovered for reuse. The regenerated anode and cathode solutions repeatedly construct the acid-base proton concentration difference ΔpH and then output electrical energy again.

[0036] The conversion of photothermal energy into electrical energy is achieved through the above cycle.

[0037] A CO2 thermosensitive crystallization photothermal regeneration power generation method, comprising:

[0038] Step 1: Use photothermal energy to drive the gas desorption in the desorbent. The desorbed gas is cyclically absorbed at the positive and negative electrodes to form a proton concentration difference and the circulating H2 is used as a proton carrier as an electrode redox reactant. The redox reaction is constructed at the two electrodes of the battery respectively, and the electrochemical system of gas crystal salt thermosensitive regeneration is used to realize the conversion of photothermal energy into electrical energy output;

[0039] Step 2: The spatial delocalization of photothermal utilization and power generation modules is achieved through the desorption of the gas medium on the salt and the absorption in the battery anode liquid. At the same time, the heat source only acts on the gas desorption, so that the mode of thermoelectric conversion is transformed from utilizing the Seebeck effect based on the temperature difference of the system to a circulation system utilizing the entropy change of the liquid-based system.

[0040] The beneficial effects of the present invention include:

[0041] (1) In the embodiment of the present invention, not only CO2 is used as a circulating medium, but also the desorption aid guanidine salt is innovatively used in combination with carbonate to produce crystals, so that the heat energy required to drive CO2 desorption is greatly reduced, which is suitable for low-energy-density photothermal energy and realizes efficient photothermal conversion. The system avoids the inefficient secondary conversion of the traditional photothermal power generation "thermal energy-mechanical energy-electrical energy" mode, and at the same time avoids the problem of strong coupling of material conductivity, thermal conductivity, and Seebeck coefficient in thermovoltaic power generation technology based on thermoelectric materials, and is difficult to independently regulate. In the technical solution of the present invention, the thermal conductivity, electrical conductivity and Seebeck coefficient of the system are decoupled from each other, so the comprehensive improvement of the performance of the thermoelectric system can be achieved by independently adjusting the solvent system, electrolyte, etc., so it has more potential in photothermal power generation power and energy efficiency. In addition, the system can also achieve a new mode of photothermal energy synergistic CO2 capture and output of electrical energy by matching CO2 with different inlet concentrations.

[0042] (2) In the embodiment of the present invention, guanidine carbonate with low water solubility can be easily precipitated and crystallized from an aqueous solution, so that CO2 in the solid guanidine carbonate with small specific heat capacity can be desorbed by photothermal drive. The desorbed CO2 is cyclically absorbed at the anode and cathode to form a proton concentration difference, and the circulating H2 is used as a proton carrier as an electrode redox reactant, thereby constructing a redox reaction at the two electrodes of the battery, thereby realizing the conversion of thermal energy into electrical energy output.

[0043] First, the power generation module uses circulating H2 as a redox reactant. That is, the electrochemical hydrogen evolution reaction (HER) occurs at the cathode of the module, alkalizing the solution (2H2O+2e - →H2+2OH - ) is used to absorb CO2; the module anode undergoes an electrochemical hydrogen oxidation reaction (HOR), releasing protons to acidify the solution and neutralize the alkalinity of the anolyte (H2→2H + +2e - The battery uses the proton concentration difference (△pH) between the positive and negative electrodes as the driving force, and the external connecting wires build an electronic circuit to achieve external discharge.

[0044] After the discharge is completed, the anode liquid enters the CO2 absorption tank to absorb saturated CO2 (CO3 2- +CO2+H2O→2HCO3 - ) and then pumped to the cathode area. After the cathode liquid and guanidine salt G crystallize, guanidine salt G is removed from HCO3 - Grab a proton H + Combined with a HCO3 - G-H2CO3 crystals are formed and precipitated, and CO3 is regenerated through this process 2-The solution is transported to the anode area of ​​the power generation module for recycling. The precipitated G-H2CO3 crystals are transported to the CO2 desorption tank, where they are heated and mixed by photothermal energy to release CO2. The released CO2 can be transported to the CO2 buffer tank for short-term storage, and then divided into two streams, which are respectively passed into the CO2 absorption tank (i.e., the anode liquid buffer tank) for regeneration of the cathode raw liquid and into the cathode area for acidification of the cathode liquid to reduce the pH value. The remaining guanidine salt after desorbing CO2 is circulated back to the cathode liquid for use.

[0045] The above process completely realizes the conversion of solar heat into electrical energy, and can adapt to different grades of heat sources to achieve efficient power generation. In addition, the system can also be applied to CO2 of different concentrations to achieve the integration of CO2 capture and thermal power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0047] Figure 1 This is a schematic diagram of the power generation system for the CO2 thermosensitive crystallization photothermal regeneration of the present invention;

[0048] Figure 2 This is a schematic diagram of the structure of the power generation system for the CO2 thermosensitive crystallization photothermal regeneration of the present invention;

[0049] Figure 3 This is the power generation curve of the system using NaHCO3 hydrogen cycle reaction;

[0050] Figure 4 This is a long-term stable power generation curve of the system using NaHCO3 hydrogen cycle reaction;

[0051] Figure 5 is the CO2 absorption concentration curve of the solution;

[0052] Figure 6 It is the G-H2CO3 desorption flow curve;

[0053] Figure 7 This is the power generation curve of the system using NaHCO3 hydrogen cycle reaction;

[0054] Figure 8 This is the power generation curve of the system using NaHCO3 as reactant;

[0055] In the figure, 1-battery anode gas chamber; 2-battery anode; 3-battery anode area; 4-cation exchange membrane; 5-battery cathode area; 6-battery cathode; 7-battery cathode gas chamber; 8-battery system; 9-load; 10-CO2 desorption tank; 11-CO2 buffer tank; 12-CO2 absorption tank. DETAILED DESCRIPTION

[0056] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0057] The embodiments of the present invention, more specifically, propose an electrochemical system and method for the photothermal regeneration of CO2 thermosensitive crystals based on a guanidine salt-CO2 crystallization thermosensitive cycle. In the inventive concept, a carbonate-based guanidine salt with low water solubility is easily precipitated and crystallized from an aqueous solution, and photothermal drive can be used to desorb CO2 from a solid carbonate-based guanidine salt with a small specific heat capacity (wherein the guanidine salt is circulated as a desorbent), and the desorbed CO2 is cyclically absorbed at the positive and negative poles to form a proton concentration difference and the circulating H2 is used as a proton carrier as an electrode redox reactant, and a redox reaction is constructed at the two poles of the battery, respectively, and the electrochemical system of the thermosensitive regeneration of CO2 crystallized guanidine salt is used to realize the conversion of photothermal energy into electrical energy output. Through the desorption of the CO2 medium on the guanidine salt G and the absorption in the battery anode liquid, the spatial delocalization of the photothermal utilization and power generation module is achieved, avoiding the problem of multi-factor coupling and difficulty in regulating the thermoelectric conversion system. At the same time, the heat source only acts on CO2 desorption, so that the thermoelectric conversion mode is transformed from the Seebeck effect based on the system temperature difference to a circulation system utilizing the entropy change of the liquid-based system, so that the system technology method can also have a good thermoelectric conversion effect under medium and low temperature application conditions.

[0058] In one embodiment, a method for power generation by photothermal regeneration of CO2 thermosensitive crystals is provided, which utilizes the special properties of crystallization after the combination of guanidine salt and carbonate to drive the desorption of CO2 in solid crystals by photothermal means and regenerate it by cyclic absorption in an alkaline absorbent, thereby forming a proton concentration difference potential at the anode and cathode of the system and discharging it to the outside, thereby realizing the conversion of photothermal energy into electrical energy.

[0059] First, a CO2 absorbent (such as sodium carbonate) is added to the anode region of the system to increase the pH value of the solution, and a cathode solute (such as sodium bicarbonate) is added to the cathode region and CO2 is continuously introduced to maintain the pH value. The positive and negative poles of the system are separated by a cation exchange membrane. At this time, a potential difference is generated because of the proton concentration difference (ΔpH) between the positive and negative poles of the system. In addition, in this system, circulating hydrogen is used as a mass-electrode coupling agent to construct a redox couple and a proton carrier. The anode undergoes an H2 oxidation reaction (HOR), loses electrons and releases protons (H +), acidifying the solution and neutralizing the alkalinity of the anode region; the cathode undergoes a hydrogen evolution reaction (HER) to obtain electrons and extract H from the solution + , alkalize the solution, and the generated H2 can be passed into the anode for recycling. During the discharge process, the cation exchange membrane separates the positive and negative electrodes and allows the cations in the anode area to pass through the membrane to the cathode area to maintain the charge balance of the system. The driving force of this process comes from the ΔpH of the positive and negative electrodes, so the sign of the end of discharge is ΔpH 0. After the discharge is over, the anode area is filled with protons (H + ) is continuously generated, eventually forming CO3 2- / HCO3 - The solution is passed into the cathode desorbed CO2 to convert it into HCO3 - The solution is circulated to the cathode for standby use. Since the CO2 desorbed from the cathode is continuously introduced during the discharge process, the cathode solution is HCO3 when the discharge ends. - Adding an appropriate amount of guanidine salt (G) to the solution can make part of the HCO3 - Transformed into G-H2CO3 crystal precipitate, the filtered solution (CO3 - ) is returned to the anode for standby use, while the crystallized part can be desorbed by low-grade photothermal CO2, and the desorbed CO2 is returned to the cathode solution and the anode solution after the reaction, and the guanidine salt G is recovered for reuse. The regenerated anode and cathode solutions repeatedly construct the acid-base proton concentration difference (ΔpH) and can output electrical energy again.

[0060] The conversion of photothermal energy into electrical energy is achieved through the above cycle.

[0061] In another embodiment, the present invention provides a power generation system based on CO2 thermosensitive crystallization and photothermal regeneration, and its overall system structure mainly includes: a power generation module, a guanidine salt-CO2 crystallization and thermosensitive regeneration module, and a fluid circulation module. Among them, the anode of the power generation module uses a carbonate solution, the cathode uses a bicarbonate solution (other solvents, CO2 alkaline absorbents and supporting electrolytes can also be used), and circulating H2 is used as a redox reactant. By using the proton concentration difference (△pH) between the positive and negative electrodes as a driving force, the external connection wire constructs an electronic circuit to achieve external discharge.

[0062] During the discharge process, the module anode undergoes an electrochemical hydrogen oxidation reaction (HOR), releasing protons to acidify the solution and neutralize the alkalinity of the anolyte (H2→2H + +2e - ), in this process part of CO3 2- Binding proton H + Formation of HCO3 - (CO3 2- +H + →HCO3 -); the module cathode undergoes an electrochemical hydrogen evolution reaction (HER), alkalizing the solution (2H2O+2e - →H2↑+2OH - ) for CO2 absorption (OH - +CO2→HCO3 - ). When the discharge is terminated, the proton concentration difference (ΔpH) between the two electrodes is reduced to 0. During the discharge process of the module, the pH of the cathode liquid continues to increase as the discharge reaction proceeds, which is used to absorb CO2 and maintain a nearly constant low pH environment after absorption. The pH of the anode liquid continues to decrease as the discharge reaction proceeds. When the pH of the anode and cathode of the module is balanced, the theoretical voltage is 0 and the discharge stops. In the system of this embodiment, a cation exchange membrane is used to separate the cathode and anode regions of the battery, which can not only keep the cations migrating from the anode region to the cathode region during the discharge process to maintain the charge balance of the system, but also separate the cathode and anode solutions to ensure a directional pH gradient and avoid discharge losses caused by the mixing of the anode and cathode solutions.

[0063] After the discharge is completed, the anode liquid is transported to the CO2 absorption tank to absorb saturated CO2 and then regenerated and circulated to the cathode area as the cathode area raw material. The cathode liquid combines with the guanidine salt G to form a precipitate G-H2CO3, which is separated from the solution by sedimentation. The solution is regenerated and circulated to the anode area as the anode area raw material. The crystals are transported to the CO2 desorption tank and the guanidine salt is regenerated and used after the CO2 is desorbed by photothermal. The CO2 is respectively passed into the CO2 absorption tank and the cathode area for recycling. Through the above cycle, the ΔpH of the anode and cathode of the battery is reconstructed to restore it to the state before discharge to complete the cycle.

[0064] The system of this embodiment achieves spatial delocalization of the discharge system and the heat regeneration system, and is connected only by a fluid transport mechanism, thus avoiding the constraint that the cold and hot ends of the electrodes in the traditional thermoelectric system must be integrated in the same power generation system space. The special crystallization reaction of the desorbent guanidine salt and carbonate allows the heat source to act only on the G-H2CO3 crystals to desorb CO2, reducing heat energy loss and achieving efficient photothermal conversion. At the same time, it can match a variety of different heat sources, all of which can achieve good power generation and circulation effects. At the same time, the system of this embodiment can coordinate CO2 capture and output electrical energy by absorbing CO2 of different concentrations. Figure 4 This is the long-term stable power generation curve of the system using NaHCO3 hydrogen cycle reaction.

[0065] In another embodiment, the present invention provides a power generation system based on CO2 thermosensitive crystal photothermal regeneration, which is described below in conjunction with the accompanying drawings. This embodiment also provides a power generation system and method for CO2 thermosensitive crystal photothermal regeneration, such as Figure 1 The load 9 is connected to the battery anode 2 and the battery cathode 6 of the battery system 8, and is used to receive and detect the electric energy output by the battery.

[0066] The battery anode gas chamber 1 is connected to the battery cathode gas chamber 7 flow channel to realize the battery hydrogen circulation system; during the reaction process, a hydrogen evolution reaction occurs on the battery cathode 6 to decompose water to produce H2, and the gas is transported to the anode area through a one-way pipeline, and an electrochemical hydrogen oxidation reaction occurs on the battery anode 2, and H2 loses electrons to generate H + .

[0067] The battery anode region 3 and the battery cathode region 5 are separated by a cation exchange membrane 4. Electrochemical hydrogen oxidation reaction occurs on the battery anode 2 (such as a platinum electrode, platinum-plated nickel mesh, etc.), and H2 loses electrons to generate H + , which reduces the alkalinity of the anode region. Under the action of the electric field, the cations (such as Na + etc.) through the cation exchange membrane 4 to reach the cathode region 5 of the battery to ensure charge balance. The anode liquid after the reaction is CO3 2- / HCO3 - It enters the CO2 absorption tank (also the anode liquid buffer tank) to absorb the CO2 desorbed by photothermal desorption and convert it into HCO3 - Realize cycle regeneration, regenerated HCO3 - The solution circulates to the cathode area as cathode reaction raw material. The reaction equation is as follows:

[0068] Anode reaction: H2→2H + +2e -

[0069] Anode reaction: 2H + +2CO3 2- →2HCO3 -

[0070] CO2 absorption tank (anolyte buffer tank) reaction: CO3 2- +CO2+H2O→2HCO3 -

[0071] The battery cathode 6 is a hydrogen evolution electrode (such as a platinum electrode, a platinum-plated nickel mesh, etc.), which undergoes an electrochemical reduction reaction to decompose water to produce H2 and OH. - , so that the cathode liquid alkalinity increases and is used to absorb the circulating CO2 desorbed by photothermal desorption to generate bicarbonate solution. The reaction equation is as follows:

[0072] Cathode reaction: 2H2O+2e - →H2+2OH -

[0073] Cathode zone reaction: 2OH - +2CO2→2HCO3 -

[0074] In the cathode area, guanidine salt G is recycled from the CO2 photothermal desorption tank and crystallizes with the cathode liquid after the reaction. Guanidine salt G is converted from HCO3 - Grab a proton H + Combined with a HCO3 - G-H2CO3 crystals are formed and precipitated, and the alkaline absorbent CO3 is regenerated through this process 2- The solution is transported to the anode area of ​​the power generation module for recycling, and the remaining guanidine salt after desorption of CO2 is recycled back to the cathode area for use. - The crystallization reaction is as follows:

[0075] Guanidine-carbonic acid crystallization reaction: G+2HCO3 - →G-H2CO3↓+CO3 2-

[0076] The G-H2CO3 crystals precipitated from the cathode liquid are transported to the CO2 desorption tank 10, where they are heated and mixed by light heat to release CO2. The released CO2 can be transported to the CO2 buffer tank 11 for short-term storage, and then divided into two streams, which are respectively passed into the CO2 absorption tank 12 (i.e., the anode liquid buffer tank) for regeneration of the cathode raw liquid and into the cathode area for acidification of the cathode liquid to reduce the pH value. The reaction formula is as follows:

[0077] CO2 desorption tank reaction: G-H2CO3→G+H2O+CO2↑

[0078] CO2 is desorbed and released under low energy density photothermal conditions, and the guanidine salt G is recycled.

[0079] The system of this embodiment can realize the stable output of converting photothermal energy into electrical energy through hydrogen circulation reaction, guanidine salt-CO2 crystallization thermal regeneration cycle and fluid pumping cycle.

[0080] In other embodiments, including but not limited to the following changes:

[0081] The electrode reactions used in the present invention are hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR), which can also be replaced by oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), or other electrochemical reactions accompanied by protons (H + ) transfer reactions, such as MnOOH, quinone, phenazine, alloxazine, etc.

[0082] The CO2 absorbent used in the present invention is a carbonate solution, which can be adapted to different types of cations, and can also include but are not limited to: KOH, NaOH, ammonia water, monoethanolamine, ethylenediamine, triethanolamine, piperazine, etc.

[0083] The present invention can also use other - 、CO32- The desorption aid combined with the precipitated crystals is used as a CO2 desorption carrier for thermal regeneration cycle, including but not limited to guanidine salts.

[0084] The system assembly method adopted by the present invention is not only applicable to regular shapes, but can also be replaced with special shapes in the future to adapt to different environments. The power generation module can be a two-chamber structure or a multi-chamber structure.

[0085] The present invention is mainly aimed at low-grade solar thermal power generation, and can also be used for high-grade thermal power generation (>150℃), and is suitable for a variety of heat sources. The system can use pure CO2 gas, or impure CO2 gas sources, such as factory flue gas, atmospheric CO2, etc. to achieve the integration of CO2 capture and thermal power generation.

[0086] Different from the previous CO2 thermal regeneration or NH3 thermal regeneration cycle batteries, the present invention utilizes guanidine salts and carbonates to produce crystals with low specific heat capacity, which greatly reduces the required heat source temperature (solid-base desorption) and avoids heat loss caused by heating additional large specific heat capacity liquids, so that it can be applied to low energy density photothermal systems.

[0087] Although the cyclic H2 reaction used in the present invention is also used in liquid flow battery systems or acid-base neutralization energy generation systems in the field of energy storage, or in electrolysis systems. However, the driving force and background significance of this type of system are completely different from those used in the present invention. For example: Liquid flow batteries, as energy storage batteries, are mainly used to solve the volatility of renewable electricity (such as wind power, photovoltaics, etc.) and store electricity. Battery discharge can only be achieved after charging, and energy loss will occur during the charge and discharge cycle. This type of battery cannot use thermal energy as a driving force (especially low-grade waste heat) to achieve battery discharge, and its technical purpose and field are completely different from the present invention.

[0088] For acid-base neutralization batteries, such as acid-base concentration difference batteries, CO2 mineralization batteries, etc., although such batteries use the pH difference between the two poles of the battery to build a potential difference, the principle of generating the pH difference in such batteries is completely different from the present invention. Such batteries need to consume a large amount of acidic and alkaline substances, and their purpose is to treat and utilize industrial waste acid (or acidic gas such as CO2, etc.) and waste alkali for energy, and they are completely unable to use thermal energy as a driving force to achieve waste heat power generation. Moreover, the consumable acid and alkali will cause the loss of reaction raw materials, and the process is irreversible.

[0089] For electrolysis systems that use electrochemical methods, it is a pure process of consuming electricity, which is fundamentally different from battery power generation systems that output energy to the outside. This type of system is mainly aimed at chemical production, and consumes electricity to obtain chemical products with economic value. It cannot achieve efficient recovery of low-grade thermal energy and net output of energy.

[0090] The advantages of the present invention are further described as follows:

[0091] 1. The system constructs H2 as a mass-to-electrochemical coupling agent, which achieves electron gain and loss through its own oxidation reaction at the anode and reduction reaction at the cathode to output electrical energy. During the whole process, H2 can be completely circulated without additional replenishment, avoiding the use of consumable electrodes in traditional batteries. In addition, the redox reaction carrier of the system can also be replaced by other mass-to-electrochemical coupling agents. For example, the available organic PCET reactants include but are not limited to phenazine, alloxazine, quinone and its derivatives. The organic PCET reactants at the battery anode undergo electrochemical oxidation reaction to release H + The acidified solution reduces the alkalinity of the anolyte; the organic PCET reactants at the cathode of the battery undergo electrochemical reduction reactions, receiving H + Alkalinizing the solution increases the alkalinity of the cathode liquid.

[0092] 2. The driving force of the power generation module of this system comes from the proton concentration difference (ΔpH) between the cathode and anode, which is constructed by CO2 absorption and thermal desorption. The cathode and anode electrolytes of this system mainly include three parts: solvent, CO2 alkaline absorbent and supporting electrolyte. The commonly used solvent is mainly water, and organic solvents can also be used, including but not limited to: alcohol solvents, ether solvents and ester solvents. The CO2 alkaline absorbent can provide an alkaline environment for the solution. Commonly used CO2 alkaline absorbents include but are not limited to: (NH4)2CO3, KOH, NaOH, ammonia water, monoethanolamine, ethylenediamine, triethanolamine, piperazine, etc. The supporting electrolyte can provide high ionic conductivity for the battery system, and conventional salt supporting electrolytes or ionic liquids can be used.

[0093] 3. This system usually uses carbon-based materials as electrodes. Common carbon-based material matrices include but are not limited to graphite felt, carbon paper, carbon cloth, carbon rods, carbon sheets, etc. Electrode materials can also be modified or modified using metal electrode substrates or metal catalysts. Common metal electrode substrates include but are not limited to: nickel foam, platinum sheets, nickel-plated platinum mesh, etc.; common catalytic carriers include but are not limited to: Pt / C, Pd / C, etc. In addition, precious metals can also be directly used as electrode materials in this system to minimize the charge transfer overpotential and effectively catalyze rapid electron transfer, thereby increasing the maximum power density of battery power generation.

[0094] 4. The power generation module and heat regeneration module of this system are completely spatially delocalized, and each part is connected by a fluid transport mechanism. This avoids the constraint that the cold and hot ends of the electrodes in the traditional thermoelectric system must be integrated in the same power generation system space. After the battery discharge is completed, the desorption aid guanidine salt G is added to the cathode liquid to precipitate part of the HCO3 -. The solution phase is transported to the anode area as raw material. The solid phase G-H2CO3 crystals are used for photothermal desorption. Since the specific heat capacity of the solid is smaller, the utilization rate of thermal energy is significantly improved. The solid guanidine salt G after desorption is returned for recycling. A part of the desorbed CO2 is used for absorption and regeneration of the anode liquid after the reaction and transported to the cathode area as raw material. Thereby, a new △pH driving force is constructed to restore the system to the state before discharge, completing the cyclic sustainable discharge of the system. Another part of the CO2 is transported to the cathode area to maintain the cathode pH environment.

[0095] 5. This system combines the special crystallization reaction of the desorption aid guanidine salt and carbonate so that the heat source only acts on the G-H2CO3 crystals to desorb CO2, avoiding a large amount of heat energy waste due to the large specific heat capacity of the solution. Reducing heat energy loss can achieve efficient photothermal conversion. At the same time, since the specific heat capacity of solid G-H2CO3 crystals is small and it is easy to heat and desorb CO2, the system can match a variety of different heat sources, all of which can achieve good power generation and circulation effects. In addition, the system can also use other heat sources that can react with CO2, HCO3 - 、CO3 2- The desorption aid combined with the precipitation crystallization is used as a CO2 desorption carrier for thermal regeneration cycle, including but not limited to guanidine salt, whose structure is as follows:

[0096]

[0097] 6. At the same time, this system can absorb CO2 of different concentrations to coordinate CO2 capture and output electrical energy.

[0098] 7. The entire system can be designed as a simple integrated device according to needs, or it can be designed into a large-scale integrated device through system series and parallel connection, and can match a variety of heat source scenarios except medium and high temperature geothermal energy.

[0099] Example 1

[0100] In another embodiment, the raw materials and sources used in the following embodiments are as follows: analytically pure sodium carbonate and sodium bicarbonate are directly used as power generation raw materials, and guanidine salt PyBIG is used as a CO2 desorption aid. The cation exchange membrane in the following embodiments can use Nafion115 membrane (DuPont). The system structure of this embodiment is as follows Figure 2 As shown, the process is as Figure 1 shown.

[0101] This embodiment provides a CO2 thermosensitive crystallization photothermal regeneration power generation system, which includes an electrolytic cell and a battery anode area 3 and a battery cathode area 5 on both sides of the electrolytic cell, wherein the battery anode area 3 and the battery cathode area 5 are separated by a cation exchange membrane 4, an alkaline absorbent Na2CO3 solution is added to the battery anode area 3, and a NaHCO3 solution is added to the battery cathode area 5. During the power generation process, CO2 is continuously introduced into the cathode, and a load 9 is connected between the battery anode 2 and the battery cathode 6. The system also includes a CO2 desorption tank 10, a CO2 buffer tank 11, and a CO2 absorption tank (i.e., an anode liquid buffer tank) 12. Each part is connected by a pumping system, and the thermal-electrical spatial delocalization and recycling of the entire system are achieved through the crystallization reaction of guanidine salt-G and CO2, G-H2CO3 photothermal desorption, and CO2 absorption regeneration. In this embodiment, the effective area in the electrolytic cell is 4cm 2 The electrolytic cell has a catalyst in the reduction tower that is a nickel-plated platinum mesh.

[0102] The specific operation steps are as follows: add 50mL of 1mol / L Na2CO3 as the anolyte in the anode area, add 50mL of 1mol / L NaHCO3 solution as the cathode in the cathode area, and continuously introduce CO2 into the anode to maintain the pH. The proton concentration difference (ΔpH) between the cathode and cathode solutions is the driving force for the discharge of the system. The pump circulates at a flow rate of 20mL / min between the electrolyzer device and the storage tank, and introduces H2 at a flow rate of 20mL / min into the battery anode 2 through the battery anode gas chamber 1. The load 9 is connected to the battery anode 2 and the battery cathode 6 of the thermoelectrochemical battery system 8 to receive and detect the electrical energy output by the battery.

[0103] Both the anode and cathode are carbon-based electrodes (such as graphite felt, carbon paper, carbon cloth, platinum electrode, platinum-plated nickel mesh, etc.). During the reaction, a hydrogen evolution reaction occurs on the battery cathode 6 to decompose water to produce H2 and OH-, and the increased alkalinity is used to absorb CO2 to generate HCO3. - The H2 generated at the cathode is transported to the battery anode gas chamber 1 through a one-way pipeline, where an electrochemical hydrogen oxidation reaction occurs on the battery anode 2, and H2 loses electrons to generate H + Acidify the anode liquid. The difference in proton concentration (ΔpH) between the cathode and cathode regions is the driving force for battery discharge. When the discharge is terminated, the pH values ​​of the two electrodes are equal. The battery anode gas chamber 1 is connected to the battery cathode gas chamber 7 flow channel to realize the battery's hydrogen circulation system.

[0104] The battery anode region 3 and the battery cathode region 5 are separated by a cation exchange membrane 4. Electrochemical hydrogen oxidation reaction occurs on the battery anode 2 (such as a platinum electrode, platinum-plated nickel mesh, etc.), and H2 loses electrons to generate H + , which reduces the alkalinity of the battery anode region 2. Under the action of the electric field, the cations (such as Na +etc.) through the cation exchange membrane 4 to reach the battery cathode region 5. The battery reaction equation is as follows:

[0105] Anode reaction: H2→2H + +2e -

[0106] Anode reaction: 2H + +2CO3 2- →2HCO3 -

[0107] Cathode reaction: 2H2O+2e - →H2+2OH -

[0108] Cathode zone reaction: 2OH - +2CO2→2HCO3 -

[0109] After the discharge is terminated, the cathode liquid and the guanidine salt G undergo a guanidine salt-CO2 crystallization reaction. The supernatant returns to the anode area for regeneration. The crystal precipitate enters the CO2 desorption tank 10, where CO2 is desorbed from G-H2CO3 under the drive of light and heat energy, and is temporarily stored in the CO2 buffer tank. The guanidine salt G returns to the cathode area for recycling. A portion of the CO2 in the CO2 buffer tank flows into the CO2 absorption tank (i.e., the anode liquid buffer tank) and neutralizes CO3 2- The alkalinity allows it to be transported to the cathode area for regeneration, and the other part is continuously passed into the cathode area to maintain the pH value of the cathode area. The reactions are as follows:

[0110] Guanidine-CO2 crystallization reaction: G+2HCO3 - →G-H2CO3↓+CO3 2-

[0111] G-H2CO3 decomposition reaction: G-H2CO3→CO2↑+G+H2O

[0112] The system can achieve stable output of thermal energy by converting it into electrical energy through hydrogen circulation reaction, CO2 crystallization thermal regeneration cycle and fluid pumping cycle.

[0113] The results show that: using the above embodiment system, the load output current program is to increase the current by 0.005A per second until the voltage drops to 0V. Initially, the load output function is not turned on, and the load displays the open circuit voltage will increase from 0V until the open circuit voltage increases to 0.85V and then stops increasing. Turn on the output button, and the current will continue to increase. As the voltage continues to decrease, the output stops when the voltage drops to 0V. After processing the data, it can be obtained that the maximum power density of this process is 102.55W / m 2 (like Figure 3 ).

[0114] Example 2

[0115] Based on the above technical solution, this example is a CO2 absorption and G-H2CO3 desorption CO2 test to prove the circulation of CO2 in the whole system and that guanidine salt G can be used as a good carrier for CO2 photothermal desorption. 50mL of Na2CO3 solution with a concentration of 0.5mol / L was prepared, and the CO2 absorption flow curve was obtained after saturation. The G-H2CO3 crystals precipitated by the reaction were heated by light to obtain the CO2 desorption concentration curve. The absorption and desorption curve is shown in Figure 2. Figure 5 , Figure 6 shown.

[0116] Comparative Example 1

[0117] The operation process of this comparative example is basically the same as that of Example 1, with the only difference being that in this comparative example, 50 mL of 1 mol / L Na2CO3 anode liquid is added to the anode region, 50 mL of 1 mol / L NaHCO3 is added to the cathode region as cathode liquid, and CO2 is continuously introduced into the cathode to maintain a relatively stable pH value. A pump is used to circulate between the electrolytic cell device, the storage tank, and the reduction tower at a flow rate of 20 mL / min, and H2 is introduced into the anode region through the battery cathode gas chamber at a flow rate of 20 mL / min, and a load is placed between the anode electrode and the cathode electrode. After the reaction is completed, the CO2 thermal desorption-absorption cycle regeneration process of the bipolar solution is not carried out, and the power generation is tested. The voltage during the discharge process is always 0 V (such as Figure 7 ), and no electricity can be generated, indicating that the discharge cannot continue without heating after the reaction.

[0118] Comparative Example 2

[0119] The operation process of this comparative example is basically the same as that of Example 1, except that in this comparative example, 50 mL of 1 mol / L Na2CO3 anode liquid is added to the anode region, 50 mL of 1 mol / L NaHCO3 is added to the cathode region as cathode liquid, and CO2 is continuously introduced into the cathode to maintain a relatively stable pH value. A pump is used to circulate the flow rate of 20 mL / min between the electrolytic cell device, the storage tank, and the reduction tower. H2 is not introduced into the anode region, and a load is placed between the anode electrode and the cathode electrode. The power generation is tested, and there is an open circuit voltage but no current (such as Figure 8 ), unable to generate electricity, indicating the importance of H2 and battery system adaptation.

[0120] The above-mentioned examples are only preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. It should be pointed out that, for those skilled in the art, without departing from the principle of the present invention, according to the technical solution and inventive concept of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as within the protection scope of the present invention.

Claims

1. A CO2 thermosensitive crystallization photothermal regeneration power generation system, characterized in that: include: A load (9), a battery system (8), a CO2 desorption tank (10), a CO2 buffer tank (11) and a CO2 absorption tank (12), wherein the battery system (8) comprises a battery anode gas chamber (1), a battery anode (2), a battery anode region (3), a cation exchange membrane (4), a battery cathode region (5), a battery cathode (6), a battery cathode gas chamber (7) and a battery system (8); The load (9) is connected to the battery anode (2) and the battery cathode (6) of the battery system (8) to receive and detect the electric energy output by the battery; the battery anode gas chamber (1) is connected to the battery cathode gas chamber (7) flow channel to realize the hydrogen circulation system of the battery; During the reaction, a hydrogen evolution reaction occurs on the battery cathode (6) to decompose water and generate H2. The gas is transported to the anode region through a one-way pipeline, and an electrochemical hydrogen oxidation reaction occurs on the battery anode (2). H2 loses electrons to generate H + ; The battery anode region (3) and the battery cathode region (5) are separated by a cation exchange membrane (4). An electrochemical hydrogen oxidation reaction occurs on the battery anode (2), and H2 loses electrons to generate H + , so that the alkalinity of the anode area is reduced; under the action of the electric field, the cations in the anode area (3) of the battery pass through the cation exchange membrane (4) to reach the cathode area (5) of the battery, ensuring charge balance; The anode liquid after the reaction is CO3 2- / HCO3 - , which enters the CO2 absorption tank (12) to absorb the CO2 desorbed by photothermal desorption and convert it into HCO3 - Realize cycle regeneration, regenerated HCO3 - The solution circulates to the cathode area as the cathode reaction raw material. The reaction equation is as follows: Anode reaction: H2→2H + +2e - Anode reaction: 2H + +2CO3 2- →2HCO3 - CO2 absorption tank reaction: CO3 2- +CO2+H2O→2HCO3 - The battery cathode (6) is a hydrogen evolution electrode, which undergoes an electrochemical reduction reaction to decompose water to produce H2 and OH - , so that the cathode liquid alkalinity increases and is used to absorb the circulating CO2 desorbed by photothermal desorption to generate bicarbonate solution. The reaction equation is as follows: Cathode reaction: 2H2O+2e - →H2+2OH - Cathode zone reaction: 2OH - +2CO2→2HCO3 - In the cathode zone, salts recycled from the CO2 photothermal desorption tank are crystallized with the cathode liquid after the reaction, and the salts include guanidine salt G; Guanidine salt G from HCO3 - Grab a proton H + Combined with a HCO3 - G-H2CO3 crystals are formed and precipitated, and the alkaline absorbent CO3 is regenerated through this process 2- The solution is transported to the anode area for recycling, and the remaining guanidine salt after desorption of CO2 is recycled back to the cathode area for use; the guanidine salt G and HCO3 - The crystallization reaction is as follows: Guanidine-carbonic acid crystallization reaction: G+2HCO3 - →G-H2CO3↓+CO3 2- The G-H2CO3 crystals precipitated from the cathode liquid are transported to the CO2 desorption tank (10), where they are heated and mixed by photothermal energy to release CO2. The released CO2 is transported to the CO2 buffer tank (11) for short-term storage, and then divided into two streams and respectively introduced into the CO2 absorption tank (12) for regeneration of the cathode raw liquid and introduced into the cathode area for acidification of the cathode liquid to reduce the pH value. The reaction formula is as follows: CO2 desorption tank reaction: G-H2CO3→G+H2O+CO2↑ CO2 is desorbed and released under light and heat, and the guanidine salt G is recycled.

2. The CO2 thermosensitive crystallization photothermal regeneration power generation system according to claim 1 is characterized in that: The battery anode (2) comprises a platinum electrode and a platinum-plated nickel mesh.

3. The CO2 thermosensitive crystallization photothermal regeneration power generation system according to claim 1 is characterized in that: The CO2 absorption tank (12) also serves as an anode liquid buffer tank.

4. The CO2 thermosensitive crystallization photothermal regeneration power generation system according to claim 1 is characterized in that: The battery cathode (6) comprises a platinum electrode and a platinum-plated nickel mesh.

5. A CO2 thermosensitive crystallization photothermal regeneration power generation system, characterized in that: The carbonate solution in the CO2 thermosensitive crystallization photothermal regeneration power generation system described in any one of claims 1 to 4 is used as a CO2 absorbent to adapt to different types of cations, wherein the carbonate solution can be replaced by any one of KOH, NaOH, ammonia water, monoethanolamine, ethylenediamine, triethanolamine, and piperazine.

6. A CO2 thermosensitive crystallization photothermal regeneration power generation system, characterized in that: The electrode reactions used in the CO2 thermosensitive crystallization photothermal regeneration power generation system described in any one of claims 1 to 4 are hydrogen evolution reaction HER and oxygen oxidation reaction HOR, and the hydrogen evolution reaction HER and oxygen oxidation reaction HOR can be replaced by oxygen evolution reaction OER and oxygen reduction reaction ORR.

7. A CO2 thermosensitive crystallization photothermal regeneration power generation system, characterized in that: The electrode reaction used in the CO2 thermosensitive crystal photothermal regeneration power generation system according to any one of claims 1 to 4 can be replaced by a proton H + Any electrochemical reaction that transfers.

8. A method for power generation by photothermal regeneration of CO2 thermosensitive crystals, characterized in that: Through hydrogen circulation reaction, guanidine salt-CO2 crystallization thermosensitive regeneration cycle and fluid pumping cycle, the photothermal energy is converted into stable electrical energy output, which specifically includes the following sub-steps: By utilizing the crystallization properties of guanidine salts after combining with carbonates, photothermal energy is used to drive the desorption of CO2 in the carbonate-based guanidine salt solid crystals and cyclically absorb and regenerate them in an alkaline absorbent, thereby forming a proton concentration difference potential at the anode and cathode of the system and discharging it to the outside, thereby realizing the conversion of photothermal energy into electrical energy.

9. The method for power generation by photothermal regeneration of CO2 thermosensitive crystals according to claim 8, characterized in that: The method utilizes the crystallization property of guanidine salt combined with carbonate to desorb CO2 in the solid crystal driven by light and heat and regenerate it by cyclic absorption in the alkaline absorbent, thereby forming a proton concentration difference potential at the anode and cathode of the system and discharging it to the outside, thereby realizing the conversion of light and heat energy into electrical energy, which specifically includes the following sub-steps: First, CO2 absorbent is added to the anode region to increase the pH value of the solution, and cathode solute is added to the cathode region and CO2 is introduced to maintain the pH value. The positive and negative electrodes of the system are separated by a cation exchange membrane. At this time, there is a proton concentration difference ΔpH between the positive and negative electrodes of the system, which generates a potential difference. In addition, by circulating hydrogen as a mass-electrode coupling agent to construct a redox couple and a proton carrier, the anode undergoes H2 oxidation reaction HOR, loses electrons and releases protons H + , acidifying the solution and neutralizing the alkalinity of the anode area; The hydrogen evolution reaction (HER) occurs at the cathode and extracts electrons from the solution. + , alkalize the solution, and the generated H2 is then passed into the anode for recycling. During the discharge process, the cation exchange membrane separates the positive and negative electrodes and allows the cations in the anode area to pass through the membrane to the cathode area to maintain the charge balance of the system; the driving force of this process comes from the ΔpH of the positive and negative electrodes, and the sign of discharge termination is ΔpH of 0; After the discharge is completed, the anode region is filled with protons H + The continuous generation of CO3 2- / HCO3 - The solution is then fed with the CO2 desorbed from the cathode to convert it into HCO3 - The solution is circulated to the cathode for standby use; During the cathode discharge process, the desorbed CO2 is introduced, and the cathode solution is HCO3 when the discharge ends. - , adding a salt to the solution, wherein the salt comprises a guanidine salt G; Guanidine salt G makes part of HCO3 - Transformed into G-H2CO3 crystal precipitate, the filtered solution CO3 - The solution is returned to the anode for standby use, while the crystallized part uses photothermal to drive CO2 desorption. The desorbed CO2 is returned to the cathode solution and the anode solution after the reaction, and the guanidine salt G is recovered for reuse. The regenerated anode and cathode solutions repeatedly construct the acid-base proton concentration difference ΔpH and then output electrical energy again. The conversion of photothermal energy into electrical energy is achieved through the above cycle.

10. A method for power generation by photothermal regeneration of CO2 thermosensitive crystals, characterized in that: include: Step 1: Use photothermal energy to drive the gas desorption in the desorbent. The desorbed gas is cyclically absorbed at the positive and negative electrodes to form a proton concentration difference and the circulating H2 is used as a proton carrier as an electrode redox reactant. The redox reaction is constructed at the two electrodes of the battery respectively, and the electrochemical system of gas crystal salt thermosensitive regeneration is used to realize the conversion of photothermal energy into electrical energy output; Step 2: The spatial delocalization of photothermal utilization and power generation modules is achieved through the desorption of the gas medium on the salt and the absorption in the battery anode liquid. At the same time, the heat source only acts on the gas desorption, so that the mode of thermoelectric conversion is transformed from utilizing the Seebeck effect based on the temperature difference of the system to a circulation system utilizing the entropy change of the liquid-based system.

Images