CN115178210A - System and method for decomposing carbon dioxide/water through electro-thermochemical cycle - Google Patents
System and method for decomposing carbon dioxide/water through electro-thermochemical cycle Download PDFInfo
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Abstract
The invention relates to a system and a method for decomposing carbon dioxide/water by electro-thermochemical cycle.A solar light-gathering device focuses solar energy; the spectrum frequency divider divides the focused solar energy according to wavelength, a short wave part with energy higher than the band gap energy of the photovoltaic cell is transmitted to the photovoltaic power generation device, and a long wave part with energy lower than the band gap energy of the photovoltaic cell is reflected to a heat collection surface of the thermoelectric reactor to provide heat; the photovoltaic power generation device generates power and provides electric energy for the thermoelectric reactor; the thermoelectric reactor utilizes the electrode material of the electrolytic cell to carry out reduction reaction under the action of heat and electric energy, and then CO is introduced 2 Or H 2 O, carrying out an oxidation reaction, CO 2 Or H 2 O is reduced to CO or H 2 . The invention utilizes solar energy in different spectral bands in multiple stages, comprehensively utilizes thermochemistry and electrochemistryThe driving force reduces the temperature of reduction reaction, and improves the solar energy utilization rate and the energy conversion efficiency.
Description
Technical Field
The invention belongs to the technical field of new energy, and particularly relates to two-step electro-thermochemical cyclic decomposition of CO based on spectrum frequency division 2 /H 2 O systems and methods.
Background
Energy is the material basis of human social activities, and is related to the progress and the civilization development of the human society with the lives and the living environment of people. Solar energy is a clean renewable energy source, and has attracted extensive attention due to its huge development potential and abundant resource distribution, but solar energy has the disadvantages of low energy density, strong dispersibility, instability, discontinuity and the like. At present, the technology of directly utilizing solar energy in a large scale with high efficiency and low cost is not mastered in China, and how to reasonably and efficiently utilize the solar energy becomes the current difficult problem and key point.
Solar two-step thermochemical cycle with metal oxide as medium for CO 2 /H 2 And (4) decomposing the O. The first step is reduction reaction, the metal oxide releases oxygen under the condition of high temperature (> 1350 ℃) and low oxygen partial pressure, and the metal ions are reduced to simple substances or lower valence. The second step is an oxidation reaction, which can be carried out at a relatively low temperature (400-1000 ℃), of the reduced metal oxide with CO 2 /H 2 O contacts and obtains an oxygen atom therein to produce CO/H 2 The metal ions are oxidized to a state before reduction, i.e., to form the initial metal oxide. This method has a higher theoretical efficiency, but the required reduction temperature is higher, resulting in higher concentration costs and higher heat losses.
Disclosure of Invention
In order to overcome the defects of the prior art, the invention provides an electro-thermochemical cyclic decomposition method for decomposing CO based on spectral frequency division 2 /H 2 The O system and the method carry out multi-stage utilization on different spectral bands of solar energy, comprehensively utilize two driving forces of thermochemistry and electrochemistry, reduce the temperature of reduction reaction in the traditional thermochemistry circulation and improve the utilization rate of the solar energy and the energy conversion efficiency of the system.
The invention is realized by the following technical scheme:
electro-thermochemical cyclic decomposition of CO based on spectral frequency division 2 /H 2 The system of O comprises a solar energy condensation device, a spectrum frequency divider, a photovoltaic power generation device and a thermoelectric reactor; the photovoltaic power generation device comprises a photovoltaic cell, and the thermoelectric reactor comprises an electrolytic cell;
the solar energy condensing device is used for focusing solar energy;
the spectrum frequency divider is used for dividing solar energy focused by the solar energy condensing device according to wavelength, transmitting a short wave part with energy higher than the band gap energy of the photovoltaic cell to the surface of the photovoltaic cell through the spectrum frequency divider, reflecting a long wave part with energy lower than the band gap energy of the photovoltaic cell to a heat collecting surface of the thermoelectric reactor by the spectrum frequency divider, and providing heat for the thermoelectric reactor;
the photovoltaic power generation device generates power by utilizing the photovoltaic cell and provides electric energy for the thermoelectric reactor;
the thermoelectric reactor is characterized in that the electrode material in the electrolytic cell is subjected to reduction reaction under the action of heat and electric energy to generate reduced electrode material and oxygen, and CO is introduced into the thermoelectric reactor after the reduction reaction is finished 2 Or H 2 O, oxidation of the reduced electrode material, CO 2 Or H 2 O is reduced to generate corresponding CO or H 2 。
Preferably, the system further comprises a thermoelectric power generation device, and when the reduction reaction in the thermoelectric reactor is completed, the thermoelectric power generation device generates power by using the solid sensible heat of the material in the electrolytic cell and supplies power to the thermoelectric reactor during the reduction reaction.
Preferably, the device also comprises a vacuum pump, and the vacuum pump is connected with the oxygen outlet of the thermoelectric reactor.
Furthermore, the device also comprises a cooling device, and an oxygen outlet of the thermoelectric reactor is connected with a vacuum pump through the cooling device.
Preferably, the device also comprises an oxidation heat exchanger, and a cold fluid inlet of the oxidation heat exchanger receives CO 2 Or H 2 O, connecting a cold fluid outlet with a gas inlet of the thermoelectric reactor; a hot fluid inlet of the oxidation heat exchanger is connected with an oxidizing gas outlet of the thermoelectric reactor, and the oxidizing gas is CO 2 Mixed gas with CO or H 2 O and H 2 The mixed gas of (2).
Preferably, the cathode and the anode in the electrolytic cell are perovskite materials, and the electrolyte is an oxygen ion type electrolyte material.
Preferably, the thermoelectric reactor is a reactor provided with a quartz window, and a long wave part with energy lower than the band gap energy of the photovoltaic cell is reflected to the quartz window by the spectrum frequency divider; or the thermoelectric reactor is a reactor without a quartz window, and the long wave part with energy lower than the band gap energy of the photovoltaic cell is reflected to the outer wall of the thermoelectric reactor by the spectrum frequency divider.
Electro-thermochemical cyclic decomposition CO based on spectrum frequency division 2 /H 2 The method based on the system comprises the following steps:
reduction reaction: the method comprises the following steps of providing electric energy for a thermoelectric reactor by using a photovoltaic power generation device, providing heat for the thermoelectric reactor by using a spectrum frequency divider, carrying out reduction reaction on an electrode material in an electrolytic cell under the action of the heat and the electric energy to generate a reduced electrode material and oxygen, and discharging the oxygen;
and (3) oxidation reaction: after the reduction reaction is finished, a spectrum frequency divider is used for providing heat for the thermoelectric reactor, and CO is introduced into the thermoelectric reactor 2 Or H 2 O, oxidation of the reduced electrode material in the electrolytic cell, CO 2 Or H 2 O is decomposed to generate corresponding CO or H 2 。
Preferably, the catalyst will contain unreacted CO 2 Or H 2 O and CO or H formed 2 The output oxidizing gas of the thermoelectric reactor and the output oxidizing gas are used for reacting with the reactant CO 2 Or H 2 Preheating O and preheated CO 2 Or H 2 And introducing the O into a thermoelectric reactor.
Electro-thermochemical cyclic decomposition CO based on spectrum frequency division 2 /H 2 The O method is based on the system comprising the thermoelectric power generation device and comprises the following steps:
reduction reaction: the photovoltaic power generation device and the temperature difference power generation device are used for providing electric energy for the thermoelectric reactor, the spectrum frequency divider is used for providing heat for the thermoelectric reactor, the electrode material in the electrolytic cell is subjected to reduction reaction under the action of heat and electric energy to generate a reduced electrode material and oxygen, and the oxygen is discharged; after the reduction reaction is finished, the temperature difference power generation device generates power by utilizing the sensible heat of the solid of the material in the electrolytic cell until the temperature of the material in the electrolytic cell is reduced to the oxidation reaction temperature;
and (3) oxidation reaction: when the temperature of the materials in the electrolytic cell is reduced to the oxidation reaction temperature, the spectrum frequency divider is used for providing heat for the thermoelectric reactor, and CO is introduced into the thermoelectric reactor 2 Or H 2 O, oxidation of the reduced electrode material in the electrolytic cell, CO 2 Or H 2 O is decomposed to generate corresponding CO or H 2 。
Compared with the prior art, the invention has the following beneficial effects:
the invention provides a two-step electro-thermochemical cyclic decomposition method for CO based on spectral frequency division 2 /H 2 And the O system is used for grading and utilizing solar energy and promoting the reduction reaction by comprehensively utilizing two driving forces of heat and electricity generated by the solar energy, so that the reduction temperature can be reduced and the utilization efficiency of the solar energy can be improved. Two-step thermochemical cycle decomposition of H with conventional solar energy 2 O or CO 2 Compared with the prior art, the method can effectively reduce the temperature required by the reduction reaction, thereby reducing the cost required by solar focusing and also reducing a large amount of heat dissipation loss caused by overhigh system temperature. Meanwhile, compared with a solar hydrogen production technology based on photovoltaic electrolyzed water, the invention can carry out electric heating multistage utilization on different spectral bands of solar energy, realize full-spectral utilization of the solar energy and improve the utilization rate of the solar energy and the energy conversion efficiency of a system.
Furthermore, the sensible heat of the solid phase of the material is utilized, the waste heat is recovered for power generation, the heat loss of the solid phase is greatly reduced, and the utilization rate of solar energy and the energy conversion efficiency of a system are improved.
Furthermore, oxygen generated by the reduction reaction is removed in time through a vacuum pump, so that the reduction reaction is promoted to be carried out efficiently.
Further, sensible heat recovery of the oxidizing gas is performed by using an oxidizing heat exchanger and is used for preheating the raw material gas CO 2 Or H 2 O, the utilization efficiency of energy can be further improved.
Drawings
FIG. 1 shows a two-step electro-thermochemical cycle CO separation method based on spectral frequency division 2 /H 2 A schematic diagram of an O system;
FIG. 2 shows a schematic diagram of an embodiment 1 of the present inventionRelating to a two-step electro-thermochemical cycle decomposition of CO based on spectral frequency division 2 System and method schematics;
FIG. 3 shows the decomposition of CO according to example 1 of the present invention 2 The solar energy-fuel conversion efficiency without a spectrum frequency divider can be achieved under different reaction conditions;
FIG. 4 shows a two-step electro-thermochemical cycle decomposition H based on spectral frequency division according to example 2 of the present invention 2 O System and Process schematic;
FIG. 5 shows a two-step electro-thermochemical cycle decomposition of CO based on spectral frequency division according to example 3 of the present invention 2 System and method schematics;
FIG. 6 is the decomposition of CO according to example 3 of the present invention 2 The solar energy-fuel conversion efficiency of the temperature difference generating set can be achieved under different reaction conditions;
FIG. 7 shows a two-step electro-thermochemical cycle decomposition H based on spectral frequency division according to example 4 of the present invention 2 O system and method schematic.
The solar photovoltaic power generation system comprises a solar energy condensation device 1, a spectrum frequency divider 2, a photovoltaic power generation device 3, an electrothermal reactor 4, a cooling device 5, a vacuum pump 6, an oxidation heat exchanger 7, an oxidation gas separator 8 and a temperature difference power generation device 9.
Detailed Description
For a further understanding of the invention, reference will now be made to the following examples, which are provided to illustrate further features and advantages of the invention, and are not intended to limit the scope of the invention as set forth in the following claims.
Referring to FIG. 1, the invention is based on two-step electro-thermochemical cyclic decomposition of CO by spectral frequency division 2 /H 2 The system comprises an O system and a solar energy concentrating device, wherein the O system comprises a solar energy concentrating device used for focusing solar energy; the spectrum frequency divider is used for dividing the focused solar energy according to the wavelength, the short wave part higher than the band gap energy of the photovoltaic cell is transmitted to the surface of the photovoltaic cell in the photovoltaic power generation device through the spectrum frequency divider, and the long wave part lower than the band gap energy of the photovoltaic cell is reflected to the heat collection surface of the thermoelectric reactor; photovoltaic power generation device, and electrolysis in thermoelectric reactorA cell electrical connection for providing electrical power to an electrolytic cell in the thermoelectric reactor; the thermoelectric reactor is used for receiving the heat provided by the spectrum frequency divider and performing two steps of reduction and oxidation of the electrolytic cell material; a cooling device for cooling the generated oxygen in the reduction step; a vacuum pump for removing generated oxygen in the reduction step in time; the oxidation heat exchanger is used for recovering the sensible heat of the gas in one step of oxidation; an oxidizing gas separator for separating CO or H as an oxidation product 2 With unreacted reactant CO 2 、H 2 O separation; an oxygen outlet of the thermoelectric reactor is connected with a vacuum pump through a cooling device, and a cold fluid inlet of the oxidation heat exchanger receives CO 2 Or H 2 And O, connecting a cold fluid outlet with a gas inlet of the thermoelectric reactor, and connecting a hot fluid inlet of the oxidation heat exchanger with an oxidation gas outlet of the thermoelectric reactor. The oxidizing gas is CO 2 CO or H 2 O、H 2 。
Preferably, the thermoelectric power generation device can also comprise a thermoelectric power generation device, and the thermoelectric power generation device utilizes the sensible heat of the solid phase of the electrode material which is difficult to recover and recover the waste heat to generate power so as to provide electric energy for the electrolytic cell in the thermoelectric reactor. The thermoelectric generation device may be a single-stage thermoelectric structure or a multi-stage thermoelectric structure.
Wherein the electrolytic cell material in the thermoelectric reactor comprises cathode, electrolyte and anode material, the solid oxide material of the cathode and the anode is subjected to reduction reaction to release oxygen in the reduction step, and CO is introduced in the oxidation step 2 Or H 2 O undergoes decomposition reaction to generate CO or H 2 。
The electrolytic cell may be of an electrolyte-supported type and an electrode-supported type, the cathode and the anode of the electrolytic cell may be of a perovskite material having a relatively high redox property, and the electrolyte may be of an oxygen ion type electrolyte material, such as Yttria Stabilised Zirconia (YSZ).
The solar light-gathering device can be a heliostat or a disc-type light-gathering device;
the spectral frequency divider can be a solid film frequency divider, a liquid frequency divider, a holographic frequency divider or a fluorescent frequency divider.
The thermoelectric reactor can be a reactor provided with a quartz window, and focused solar energy directly heats the electrolytic cell material through the quartz window; or the reactor without the quartz window can focus solar energy to heat the outer wall of the reactor and indirectly heat the electrolytic cell material.
The system of the invention has the following operation modes:
when the temperature difference power generation device is not arranged, in the reduction step, the active materials of the cathode and the anode are driven by the heat energy and the electric energy provided by the spectrum frequency divider and the photovoltaic power generation device to carry out oxygen release reaction to generate a reduced material, and the vacuum pump is used for evacuating oxygen in time; in the oxidation step, CO is introduced only under the drive of heat energy 2 Or H 2 O, oxidation of the reduced materials of the cathode and anode, CO 2 Or H 2 CO or H produced by reduction of O 2 Output the thermoelectric reactor and CO 2 Or H 2 After heat exchange of O, CO after heat exchange 2 Or H 2 The O enters the thermoelectric reactor.
When the temperature difference power generation device is arranged, in the reduction step, the active materials of the cathode and the anode are driven by the heat energy and the electric energy provided by the spectrum frequency divider, the photovoltaic power generation device and the temperature difference power generation device to carry out oxygen release reaction to generate a reduced material, and the oxygen is pumped out in time by a vacuum pump; after the reduction reaction is finished, the temperature difference power generation device generates power by utilizing the solid sensible heat of the material in the electrolytic cell, when the temperature of the material in the electrolytic cell is reduced to the oxidation reaction temperature, the temperature difference power generation device is disconnected with the electrolytic cell to carry out the oxidation reaction, and in the oxidation step, CO is introduced only under the drive of heat energy 2 Or H 2 O, oxidation of the reduced materials of the cathode and anode, CO 2 Or H 2 CO or H produced by decomposition of O 2 Output of the thermoelectric reactor, output of CO 2 CO or H 2 O、H 2 The mixed gas is used for preheating reactant CO by recycling gas phase waste heat through an oxidation heat exchanger 2 Or H 2 O，CO 2 CO or H 2 O、H 2 The mixed gas passes through an oxidizing gas separator to separate CO 2 With CO or H 2 O and H 2 And (5) separating.
Example 1
To decompose CO 2 Production of CO as an example to an embodimentThe formula is illustrated.
Referring to fig. 2, in this embodiment, the system mainly comprises a solar concentrating apparatus 1 for focusing solar energy; the spectrum frequency divider 2 is used for dividing solar radiation according to wavelength, a short wave part higher than the band gap energy of the photovoltaic cell is transmitted to the surface of the photovoltaic cell through the spectrum frequency divider, and a long wave part lower than the band gap energy of the photovoltaic cell is reflected to the heat collection surface of the thermoelectric reactor; a photovoltaic power generation device 3 for supplying electric energy to the thermoelectric reactor 4; the thermoelectric reactor 4 is used for receiving heat provided by the focused solar energy and performing two steps of reduction and oxidation of the electrolytic cell material; a cooling device 5 for cooling the oxygen in the reduction step; a vacuum pump 6 for removing oxygen in time at the reduction step; and the oxidation heat exchanger 7 is used for recovering the sensible heat of the gas in one step of oxidation. Wherein inside the thermoelectric reactor 4 is an active material of an electrolytic cell structure comprising a cathode, an electrolyte, an anode, the process is completed by two-step reactions of reduction and oxidation of the anode and cathode materials.
In the reduction step, solar energy is focused and converged to the surface of a spectrum frequency divider 2 through a solar focusing device 1, wherein a short wave part higher than the band gap energy of the photovoltaic cell is transmitted to a photovoltaic power generation device 3 through the spectrum frequency divider, and the photovoltaic power generation device 3 converts the solar energy into electric energy; the long wave portion below the band gap energy of the photovoltaic cell is reflected to the thermoelectric reactor 4, providing heat for the reaction. Under the common driving of electric energy and heat energy, the anode and cathode materials are reduced to release oxygen. The reduction reaction is carried out under the following conditions:
wherein, Δ g δ,red 、
T red 、
ΔG elec 、R、p 0 Gibbs free energy change and material respectively for reduction reactionStandard reduction enthalpy, standard reduction entropy, reduction temperature, reduced oxygen partial pressure, voltage gibbs free energy, gas constant, standard pressure.
During the oxidation reaction, the cathode material reacts with CO entering the thermoelectric reactor 4 2 Reacting to absorb oxygen atoms therein, and oxidizing the cathode material while CO is being oxidized 2 Is reduced to produce CO. The solar-fuel conversion efficiency of the present system and method is:
wherein n is CO 、HHV CO 、Q red 、
W sep 、η adsorption 、η spec 、w elec 、η PV Respectively CO yield, CO high calorific value, heat absorption of cathode reduction reaction, energy required by heating electrolytic cell material, and CO 2 Energy required for heating, electric quantity required by vacuum pump, and CO 2 And the electric quantity required by CO separation, the absorption efficiency of the thermoelectric reactor to solar energy, the efficiency of a spectrum frequency divider, the electric energy required by cathode reduction and the photovoltaic power generation efficiency.
The traditional two-step thermochemical cycle reduction temperature is generally above 1300 ℃, and in the electro-thermochemical cycle, the required reduction reaction temperature is greatly reduced because the electric energy and the heat energy drive the reduction reaction together. FIG. 3 shows the oxidation temperature at 1000 ℃ and the reduced oxygen partial pressure at 10 -3 bar, auxiliary voltage of 0.4V, and existence of non-spectrum frequency divider system to decompose CO at different reduction reaction temperatures 2 The solar energy conversion efficiency can be achieved, and the system has higher efficiency when the temperature is lower than 1300 ℃, and the spectrum frequency divider can improve the solar energy utilization efficiency. The parameters selected during the calculation are listed in table 1.
TABLE 1 evaluation of the above parameters in the efficiency calculation
Example 2
In the following, to decompose H 2 Production of H from O 2 The embodiments are illustrated by way of example.
Referring to fig. 4, in this embodiment, the system mainly comprises a solar concentrating device 1 for focusing solar energy; the spectrum frequency divider 2 is used for dividing solar radiation according to wavelength, a short wave part higher than the band gap energy of the photovoltaic cell is transmitted to the surface of the photovoltaic cell through the spectrum frequency divider, and a long wave part lower than the band gap energy of the photovoltaic cell is reflected to the heat collection surface of the thermoelectric reactor; a photovoltaic power generation device 3 for supplying electric energy to the thermoelectric reactor 4; a thermoelectric reactor 4 for receiving the heat provided by the focused solar energy and performing two steps of reduction and oxidation of the electrolytic cell material; a cooling device 5 for cooling the oxygen in the reduction step; a vacuum pump 6 for removing oxygen in time at the reduction step; the oxidation heat exchanger 7 is used for recovering the sensible heat of the hydrogen in one step of oxidation; an oxidizing gas separator 8 for separating unreacted H 2 O with H produced by reaction 2 And (5) separating. Wherein inside the thermoelectric reactor 4 is an active material of an electrolytic cell structure comprising a cathode, an electrolyte, an anode, and the process accomplishes decomposition of H by two-step reactions of reduction and oxidation of the anode and cathode materials 2 Production of H from O 2 The process of (1).
In the reduction step, solar energy is focused and converged to the surface of a spectrum frequency divider 2 through a solar focusing device 1, wherein a short wave part higher than the band gap energy of the photovoltaic cell is transmitted to a photovoltaic power generation device 3 through the spectrum frequency divider, and the photovoltaic power generation device 3 converts the solar energy into electric energy; the long wave portion below the band gap energy of the photovoltaic cell is reflected to the thermoelectric reactor 4, providing heat for the reaction. Under the driving of electric energy and heat energy, the anode and cathode materials are reduced to release oxygen.
During the oxidation reaction, the active material reacts with H entering the fixed bed reactor 4 2 O reaction, absorbing oxygen atoms therein, H while the active material is oxidized 2 O is reduced to form H 2 。
Example 3
As shown in fig. 5, in example 3, a thermoelectric power generation device 9 is added to example 1, and the thermoelectric power generation device 9 recovers waste heat to generate power by using sensible heat of a solid phase of a material which is difficult to recover, thereby supplying electric energy to the thermoelectric reactor 4.
The solar-fuel conversion efficiency of the present system and method is:
wherein, E, F, n CO 、HHV CO 、Q red 、
W gap 、
W sep 、η adsorption 、η spec 、w elec 、η PV 、η gap Respectively comprising voltage, faraday constant, CO output, CO high-grade calorific value, cathode reduction reaction heat absorption, energy required by heating of electrolytic cell material, electric energy generated by a thermoelectric generation device, and CO 2 Energy required for heating, electric quantity required by vacuum pump, and CO 2 And the electric quantity required by CO separation, the absorption efficiency of the thermoelectric reactor to solar energy, the efficiency of a spectrum frequency divider, the electric energy required by cathode reduction, the photovoltaic power generation efficiency and the power generation efficiency of a temperature difference power generation device.
FIG. 6 shows the oxidation temperature at 1000 ℃ and the reduced oxygen partial pressure at 10 -3 The bar and the auxiliary voltage are 0.4V, and the power generation device decomposes CO under different reduction reaction temperatures under different conditions with or without temperature difference 2 The solar energy conversion efficiency can be achieved. When the reduction temperature is 1100 ℃, the efficiencies of the non-temperature difference power generation device and the temperature difference power generation device are 39.1 percent and 42.2 percent respectively, and the energy efficiency can be obviously improved by the temperature difference power generation device. The parameters selected during the calculation are listed in table 2.
TABLE 2 values of the above parameters in the efficiency calculation
Example 4
As shown in fig. 7, in example 4, a thermoelectric power generation device 9 is added to example 2, and the thermoelectric power generation device 9 recovers waste heat to generate power by using sensible heat of a solid phase of a material, which is difficult to recover, to supply electric energy to the thermoelectric reactor 4.
Two-step electro-thermochemical cyclic decomposition of CO as demonstrated by the present invention 2 /H 2 The O system and the O method can utilize solar energy according to wavelength in a grading way, and improve the utilization efficiency of the solar energy. And the reduction reaction is driven by electricity and thermochemistry, so that the reduction reaction temperature is reduced, and the heat loss is reduced. The system is expected to achieve higher solar energy conversion efficiency and has very high popularization value.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The system for decomposing carbon dioxide/water by electro-thermochemical cycle is characterized by comprising a solar light gathering device (1), a spectrum frequency divider (2), a photovoltaic power generation device (3) and a thermoelectric reactor (4); the photovoltaic power generation device (3) comprises a photovoltaic cell, and the thermoelectric reactor (4) comprises an electrolytic cell;
a solar energy concentrating device (1) for concentrating solar energy;
the spectrum frequency divider (2) is used for dividing solar energy focused by the solar energy condensing device (1) according to wavelength, a short wave part with energy higher than the band gap energy of the photovoltaic cell is transmitted to the surface of the photovoltaic cell through the spectrum frequency divider (2), and a long wave part with energy lower than the band gap energy of the photovoltaic cell is reflected to a heat collecting surface of the thermoelectric reactor (4) by the spectrum frequency divider (2) to provide heat for the thermoelectric reactor (4);
a photovoltaic power generation device (3) which generates power by using a photovoltaic cell and provides electric energy for the thermoelectric reactor (4);
the thermoelectric reactor (4) is used for carrying out reduction reaction on the electrode material in the electrolytic cell under the action of heat and electric energy to generate reduced electrode material and oxygen, and CO is introduced into the thermoelectric reactor (4) after the reduction reaction is finished 2 Or H 2 O, oxidation of the reduced electrode material, CO 2 Or H 2 O is reduced to generate corresponding CO or H 2 。
2. The system for decomposition of carbon dioxide/water by electro-thermochemical cycle according to claim 1, characterized by further comprising a thermoelectric generation device (9), wherein when the reduction reaction in the thermoelectric reactor (4) is completed, the thermoelectric generation device (9) generates electricity by using the sensible heat of the solid of the material in the electrolytic cell and supplies electricity to the thermoelectric reactor (4) during the reduction reaction.
3. The system for the electro-thermochemical cyclic decomposition of carbon dioxide/water according to claim 1, characterized in that it also comprises a vacuum pump (6), the vacuum pump (6) being connected to the oxygen outlet of the thermoelectric reactor (4).
4. An electro-thermochemical cyclic decomposition system of carbon dioxide/water according to claim 3, characterized in that it further comprises cooling means (5), the oxygen outlet of the thermoelectric reactor (4) being connected to a vacuum pump (6) through the cooling means (5).
5. System for the electro-thermochemical cyclic decomposition of carbon dioxide/water according to claim 1, characterized in that it also comprises an oxidation heat exchanger (7), the cold fluid inlet of which (7) receives CO 2 Or H 2 O, connecting a cold fluid outlet with a gas inlet of the thermoelectric reactor (4); a hot fluid inlet of the oxidation heat exchanger (7) is connected with an oxidation gas outlet of the thermoelectric reactor (4), and the oxidation gas is CO 2 Mixed gas with CO or H 2 O and H 2 The mixed gas of (2).
6. The system for decomposition of carbon dioxide/water by electro-thermochemical cycle of claim 1 wherein the cathode and anode in the electrolytic cell are perovskite materials and the electrolyte is an oxygen ion type electrolyte material.
7. An electro-thermochemical cyclic decomposition system of carbon dioxide/water according to claim 1, characterized in that the thermoelectric reactor (4) is a reactor equipped with a quartz window onto which the long-wave part with energy lower than the band-gap energy of the photovoltaic cell is reflected by the spectral divider (2); or the thermoelectric reactor (4) is a reactor without a quartz window, and the long wave part with energy lower than the band gap energy of the photovoltaic cell is reflected to the outer wall of the thermoelectric reactor (4) by the spectrum frequency divider (2).
8. An electro-thermo-chemical cyclic decomposition method of carbon dioxide/water, based on the system of any one of claims 1 or 3-7, comprising:
reduction reaction: the photovoltaic power generation device (3) is used for providing electric energy for the thermoelectric reactor (4), the spectrum frequency divider (2) is used for providing heat for the thermoelectric reactor (4), the electrode material in the electrolytic cell is subjected to reduction reaction under the action of heat and electric energy to generate a reduced electrode material and oxygen, and the oxygen is discharged;
and (3) oxidation reaction: after the reduction reaction is finished, the spectrum frequency divider (2) is used for providing heat for the thermoelectric reactor (4), and CO is introduced into the thermoelectric reactor (4) 2 Or H 2 O, oxidation of the reduced electrode material in the electrolytic cell, CO 2 Or H 2 O is decomposed to generate corresponding CO or H 2 。
9. The electro-thermochemical cycle decomposition method of carbon dioxide/water according to claim 8, characterized in that it comprises unreacted CO 2 Or H 2 O and CO or H formed 2 The oxidizing gas is output from the thermoelectric reactor (4) and used for reacting with the reactant CO 2 Or H 2 Preheating O and preheated CO 2 Or H 2 O-shaped ringInto a thermoelectric reactor (4).
10. A method for decomposing carbon dioxide/water by electro-thermochemical cycle, characterized in that, based on the system of claim 2, it comprises:
reduction reaction: the photovoltaic power generation device (3) and the temperature difference power generation device (9) are used for providing electric energy for the thermoelectric reactor (4), the spectrum frequency divider (2) is used for providing heat for the thermoelectric reactor (4), the electrode material in the electrolytic cell is subjected to reduction reaction under the action of the heat and the electric energy to generate the electrode material in a reduction state and oxygen, and the oxygen is discharged; after the reduction reaction is finished, the temperature difference power generation device (9) utilizes the sensible heat of the solid of the material in the electrolytic cell to generate power until the temperature of the material in the electrolytic cell is reduced to the oxidation reaction temperature;
and (3) oxidation reaction: when the temperature of the materials in the electrolytic cell is reduced to the oxidation reaction temperature, the spectrum frequency divider (2) is used for providing heat for the thermoelectric reactor (4), and CO is introduced into the thermoelectric reactor (4) 2 Or H 2 O, oxidation of the reduced electrode material in the electrolytic cell, CO 2 Or H 2 O is decomposed to generate corresponding CO or H 2 。
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| CN116573609A (en) * | 2023-07-14 | 2023-08-11 | 中国电建集团西北勘测设计研究院有限公司 | Solar thermochemical hydrogen production power generation system and method |
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