Chemical reaction devices

Abstract

To improve conversion efficiency into a chemical energy of a product material from a solar energy.SOLUTION: In a chemical reaction device, a power is supplied from a PV module 100 to an EC module 102 to generate a chemical reaction by using the power. In the PV module 100, from a light reception surface side, a top cell module in which nt photoelectric conversion cells using a light absorption material of which a band gap is 1.3 eV or more and 1.7 eV or less are series connected and a bottom cell module in which the nb photoelectric conversion cells are series connected by using the light absorption material of which the band gap is 1.0 eV or more and 1.2 eV or less, are stacked and connected in parallel. The EC module 102 is constructed by series connecting nEC EC reactor. nt / nEC is 1.1 or more and nb / nEC is 2 or more.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] This invention relates to a chemical reaction device. [Background technology]

[0002] The use of solar energy is an essential technology for achieving carbon neutrality. In addition to solar power generation, which is already widely used, research is being actively conducted on artificial photosynthesis, which uses only solar energy to synthesize hydrogen (H2) from water (H2O), and carbon monoxide (CO) and formic acid (HCOOH) from carbon dioxide (CO2) and water (H2O).

[0003] In the current state of artificial photosynthesis technology, the method combining photoelectric (PV) cells and electrochemical (EC) reactors has a higher conversion efficiency (η) from solar energy to chemical energy compared to the method using photocatalysts. STC High values ​​of η are obtained. For example, the thermodynamic threshold voltage for the reaction that decomposes water (H2O) to produce hydrogen (H2) is 1.23V, and the thermodynamic threshold voltages for the reactions that produce carbon monoxide (CO) and formic acid (HCOOH) from carbon dioxide (CO2) and water (H2O) are 1.34V and 1.43V, respectively. However, in order to drive an EC reactor and obtain a reaction rate that is practically meaningful, an applied voltage of at least 1.6V to 1.8V is required, which is an overvoltage added to these values. Therefore, the conversion efficiency from solar energy to chemical energy (η) STC To increase the performance, PV cells with two junctions (2J: double-junction) or three junctions (3J: triple-junction) are currently used.

[0004] Furthermore, in order to resolve the problems of the 2J-PV cells and 3J-PV cells described below, a configuration has been proposed in which a 4-terminal tandem PV module is used, in which a top PV module consisting of multiple semi-transparent PV cells connected in series and a bottom PV module consisting of multiple PV cells with a narrower band gap than the PV cells used in the top module are connected in series, stacked with the top PV module on top (light irradiation side), and each is connected to a separate EC reactor (Non-Patent Literature 1). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] RT White, et al., J. Mater. Chem. A 5, 13112 (2017) [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] By the way, 2J-PV cells and 3J-PV cells have the following two technical problems. The first problem is that the current drops significantly when the solar spectrum fluctuates. This is because current matching between the top cell and bottom cell is no longer possible, and the current of the entire cell is limited by the minimum value of the photocurrent of the top cell and bottom cell. The second problem arises from the constraints of real-world materials. The band gap Eg of organic-inorganic hybrid perovskite (PVK) solar cells changes depending on their composition. Currently, approximately 25% of cells with a composition that gives a band gap Eg = 1.5 eV have the highest photoelectric conversion efficiency (η). PV ) and high-quality cells close to this have been realized in the band gap range Eg = 1.2 eV to 1.7 eV. Therefore, it can be used as the top cell of a 2J cell. On the other hand, the currently practical bottom cell is a crystalline silicon (Si) PV cell (band gap Eg = 1.12 eV, photoelectric conversion efficiency (η PV) with a maximum value of 26.3%), and a Cu(In,Ga)Se2 (CIGS) cell (bandgap Eg = 1.08 eV, photoelectric conversion efficiency (η PV ) is limited to a maximum value of 23.4%). Since the bandgap Eg of the PVK top cell is subject to the constraint of current matching with the bottom cell, the design freedom for adapting to the characteristics of the EC reactor is limited.

[0007] Also, a four-terminal tandem PV module solves the above current matching problem. Furthermore, since the number of series connections of each PV module of the top cell and the bottom cell and the area ratio of the EC reactors to which they are connected are design parameters, high conversion efficiency (η STC ) can be obtained by performing an optimal design. However, since the EC reactor is divided into two, the structure becomes complicated, and there is a technical problem that if the design deviates greatly from the optimal value, the conversion efficiency (η STC ) decreases.

Means for Solving the Problem

[0008] One aspect of the present invention is a chemical reaction device that supplies power from a photoelectric conversion module to an electrochemical module and causes a chemical reaction using the power. The photoelectric conversion module includes, from the light-receiving surface side, a top cell module in which n t photoelectric conversion cells using a light absorption material with a bandgap of 1.3 eV or more and 1.7 eV or less are connected in series, and a bottom cell module in which n b photoelectric conversion cells using a light absorption material with a bandgap of 1.0 eV or more and 1.2 eV or less are connected in series, which are stacked and connected in parallel to each other. The electrochemical module has a configuration in which n EC electrochemical reactors are connected in series, and n t / n EC is 1.1 or more, and n b / n EC is 2 or more, which is a chemical reaction device characterized by this.

[0009] In this case, the photoelectric conversion cell constituting the top cell module is preferably an organic-inorganic hybrid perovskite cell.

[0010] Furthermore, the photoelectric conversion cell constituting the bottom cell module is preferably a crystalline silicon cell or a Cu(in,Ga)Se2 cell.

[0011] Furthermore, the electrochemical reactor is preferably capable of producing hydrogen (H2) and oxygen (O2) from water (H2O).

[0012] Also, n t / n EC n is between 1.1 and 1.8, b / n EC It is preferable that the value be between 2.0 and 3.0.

[0013] Furthermore, the electrochemical reactor is preferably capable of producing carbon monoxide (CO) or formic acid (HCOOH) from carbon dioxide (CO2) and water (H2O).

[0014] Also, n t / n EC n is between 1.3 and 3.0, b / n EC It is preferable that the value is between 2.3 and 4.0.

[0015] Furthermore, the electrochemical reactor is preferably capable of reducing carbon dioxide (CO2). [Effects of the Invention]

[0016] According to the present invention, the conversion efficiency from solar energy to the chemical energy of the product can be improved compared to a chemical reaction device combining a multi-junction photoelectric conversion cell and an EC reactor. Furthermore, compared to a chemical reaction device combining a four-terminal tandem type chemical reaction device and a two-part EC reactor, the structure can be simplified while maintaining the conversion efficiency from solar energy to the chemical energy of the product. [Brief explanation of the drawing]

[0017] [Figure 1] This figure shows the configuration of the chemical reaction device in Example 1 of the present invention. [Figure 2] This figure shows the configuration of the chemical reaction device in Example 2 of the present invention. [Figure 3] This figure shows the configuration of the chemical reaction device in Example 3 of the present invention. [Figure 4] This figure shows the configuration of the chemical reaction device in Comparative Example 1. [Figure 5] This figure shows the configuration of the chemical reaction device in Comparative Example 2. [Figure 6] This figure shows the calculated results and measured values ​​of various characteristics of the photoelectric conversion cell. [Figure 7] This figure shows the calculation results of the operating current density Jop~ in an embodiment of the present invention. [Figure 8] This figure shows the calculation results of the operating current density Jop~ in an embodiment of the present invention. [Figure 9] This figure shows the calculation results of the operating current density Jop~ in an embodiment of the present invention. [Figure 10] This figure shows the calculation results for the optimal values ​​of the operating current density Jop~, the number of PVK cells nPVK~, and the number of Si cells nSi~, as well as the annual average value of the operating current density Jop~, with respect to the operating voltage Vop~ in an embodiment of the present invention. [Figure 11] This figure shows the calculation results of the conversion efficiency in an embodiment of the present invention. [Figure 12] This figure shows the calculation results of the conversion efficiency relative to the area ratio APVK of the EC reactor connected to the PVK cell for the chemical reaction device for water electrolysis hydrogen generation of the present invention. [Figure 13] This figure shows the calculation results of the conversion efficiency relative to the area ratio APVK of the EC reactor connected to the PVK cell for the carbon dioxide decomposition and carbon monoxide generation chemical reaction device of the present invention. [Modes for carrying out the invention]

[0018] Figures 1 to 5 show various embodiments of chemical reaction devices. Each chemical reaction device has a configuration in which a photoelectric conversion (PV) module 100, which is a combination of a top cell 10 and a bottom cell 12, is connected to an electrochemical (EC) module 102.

[0019] The top cell 10 is a photoelectric conversion cell with a wider band gap than the bottom cell 12. The top cell 10 is, for example, an organic-inorganic hybrid perovskite (PVK) solar cell. The band gap Eg of a PVK cell changes depending on its composition, but for example, a band gap Eg of 1.2 eV to 1.7 eV is preferable. Currently, in compositions where the band gap Eg = 1.5 eV, approximately 25% achieve the highest photoelectric conversion efficiency (η). PV ) has been obtained.

[0020] The bottom cell 12 is a photoelectric conversion cell with a narrower band gap than the top cell 10. The bottom cell 12 is, for example, a crystalline silicon (Si) PV cell or a Cu(In,Ga)Se2 (CIGS) cell. A Si cell, for example, has a band gap Eg of 1.12 eV and a photoelectric conversion efficiency (η PV The highest value obtained for this is 26.3%. The CIGS cell, for example, has a band gap Eg of 1.08 eV and a photoelectric conversion efficiency (η PV The highest value obtained was 23.4%.

[0021] In the following explanation, the top cell 10 will be described as a PVK cell and the bottom cell 12 as a Si cell. However, the explanation is not limited to these combinations.

[0022] The EC module 102 includes one or more electrochemical (EC) reactors 14. The EC reactors 14 use electrical energy to produce chemical reactions. In this embodiment, electrical energy is supplied from the PV module 100 to the EC reactors 14. The chemical reactions produced in the EC reactors 14 can be, for example, reactions that decompose water (H2O) to produce hydrogen (H2) or reactions that produce carbon monoxide (CO) or formic acid (HCOOH) from carbon dioxide (CO2) and water (H2O).

[0023] Figure 1 shows a 2PVK / 3Si-1EC type chemical reaction device in which a PV module 100 is constructed by stacking and connecting in parallel a top cell module consisting of two top cells 10 connected in series from the light-receiving surface side and a bottom cell module consisting of three bottom cells 12 connected in series, and the PV module 100 is connected to an EC module 102 consisting of one EC reactor 14.

[0024] Figure 2 shows a 3PVK / 5Si-2EC type chemical reaction device in which a PV module 100 is constructed by stacking and connecting in parallel a top cell module consisting of three top cells 10 connected in series from the light-receiving surface side and a bottom cell module consisting of five bottom cells 12 connected in series, and the PV module 100 is connected to an EC module 102 consisting of two EC reactors 14 connected in series.

[0025] Figure 3 shows the view from the light-receiving surface side η PVK A top cell module consisting of a top cell 10 with several cells connected in series and η Si A PV module 100 is constructed by stacking and connecting in parallel bottom cell modules, each consisting of a bottom cell 12 connected in series, n EC The EC module 102 consists of EC reactors 14 connected in series, to which the PV module 100 is connected. PVK PVK / η Si Si-n EC This shows an EC-type chemical reaction device.

[0026] Figure 4 shows a 2J-1EC type chemical reaction device in which a PV module 100 is composed of a 2J-PV cell, with a top cell 10 and a bottom cell 12 joined together from the light-receiving surface side, and the PV module 100 is connected to an EC module 102 consisting of one EC reactor 14.

[0027] Figure 5 shows a tandem-type 4T-3PVK / 5Si-2EC chemical reaction device in which a top cell module consisting of three top cells 10 connected in series from the light-receiving surface side and a bottom cell module consisting of three bottom cells 12 connected in series are stacked and arranged, and the top cell module and bottom cell module are connected to two EC modules 102 consisting of two EC reactors 14 connected in series, respectively.

[0028] In this embodiment, the 2PVK / 3Si-1EC type is shown in Figure 1, the 3PVK / 5Si-2EC type is shown in Figure 2, and the η type is shown in Figure 3. PVK PVK / η Si Si-n EC The EC type chemical reaction devices correspond to Examples 1 to 3. The 2J-1EC type chemical reaction device in Figure 4 and the 4T-3PVK / 5Si-2EC type chemical reaction device in Figure 5 correspond to Comparative Examples 1 and 2.

[0029] [Evaluation of Current Density-Voltage (JV) Characteristics] For each chemical reaction device shown in Figures 1 to 5, the photoelectric conversion operation of the PV module 100 was modeled, and the current density-voltage (JV) characteristics were determined. The intersection of the JV curve of the PV module 100 and the load curve of the EC reactor 14 represents the operating point of the chemical reaction device. The current density J at this operating point is the conversion efficiency η from solar energy to chemical energy. STC It was converted to [this].

[0030] It was assumed that the areas of PV module 100 and EC module 102 were equal in each chemical reaction device. Furthermore, the conversion efficiency η was calculated when irradiated with AM1.5G:1 sun, which is the standard condition shown in "Reference Solar Spectral Irradiance: Air Mass 1.5, National Renewable Energy Laboratory, available from https: / / rredc.nrel.gov / solar / spectra / am1.5 / ." STC The band gap of the PVK cell was optimized to maximize the value. Additionally, the annual average conversion efficiency η was calculated using the solar radiation spectrum database provided in "NEDO, Solar Radiation Database." STC They sought it.

[0031] Current density j of a PV cell (single cell) (PV) This can be expressed by equation (1) from the equivalent circuit consisting of a constant current source, a diode, and a series resistor.

number

[0032] Here, j ph ,j0,r s q,k are the photocurrent density, the reverse saturation current density of the diode, and the series resistance, respectively. B ,T are the elementary charge, Boltzmann constant, and the temperature of the device (here assumed to be 300K), respectively. External quantum efficiency of photoelectric conversion η EQE If we approximate that is a constant value independent of the photon energy, then the photocurrent density j ph The band gap E of the light-absorbing material used in the cell is g and the photon number spectrum of sunlight n sun (h(bar)ω) is determined by equation (2) (where h(bar) = h / 2π, and h is Planck's constant).

number

[0033] The component of the diode's inverse saturation current density j0 due to radiative recombination is expressed by generalized Planck's law. The external luminescence efficiency η is the ratio of this component to the total recombination current density, which includes both radiative and non-radiative processes. ERE Using this, and further approximating the Fermi-Dirac distribution function with the Boltzmann distribution function, we derive equation (3). Here, h and c are Planck's constant and the speed of light in a vacuum, respectively.

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[0034] The top cell 10 is a PVK cell and the bottom cell 12 is a Si cell, each with n PVK individual and n Si Current density J of a voltage-matched tandem PV module 100, in which several series-connected submodules are connected in parallel. (PV) This is shown by formula (4). However, j (PVK) and j (Si) These represent the current densities of the PVK cell and the Si cell, respectively.

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[0035] Current density j of PVK cell (PVK) The band gap E is calculated based on equations (1) to (3). g , and the external quantum efficiency η of photoelectric conversion EQE The respective band gaps E of the PVK cells g PVK and the external quantum efficiency η of photoelectric conversion EQE PVK It can be obtained by substituting it with.

[0036] On the other hand, the current density j of the Si cell (Si) This is expressed by equation (5) because the light that passes through the PVK cell reaches the Si cell.

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[0037] n EC Current density J of EC module 102, in which several EC reactors are connected in series. (EC) The current density j of each EC reactor (EC) This relationship is shown in equation (6).

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[0038] From the solution to the system of equations (4) and (6), the current density J at the operating point of the chemical reaction device is obtained. op and voltage V op The following is required. In this case, the current density J op n connected in series EC Since it flows through individual EC reactors, J op ~(In mathematical formulas, the tilde ~ is used to indicate a variable) = n EC ·J op This represents the current density that contributes to the reaction. The number of PVK cells and Si cells per EC reactor are n, respectively. PVK ~=n PVK / n EC and n Si ~=n Si / n EC Defined as follows, the current density and voltage are given by J~=n EC J and V = V / n EC If defined as such, the current density J op ~ and voltage V op The simultaneous equations to find ~ are shown in equation (7). That is, the structure of the chemical reaction device is the number of PVK cells n per EC reactor. PVK ~ and the number of SiCells n Si It is defined by the following two parameters: ~.

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[0039] In the reaction that decomposes water (H2O) to produce hydrogen (H2), the efficiency of converting solar energy to the chemical energy of hydrogen is η H2 This is shown by formula (8). However, P sun This represents solar radiation intensity.

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[0040] The conversion efficiency η of the reaction for the production of carbon monoxide (CO) by the reduction of carbon dioxide (CO2) CO Regarding this, considering that the Faradaic efficiency η FE depends on the applied voltage to the EC reactor, it is shown by Equation (9).

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[0041] The current density J of the 2J-1EC type chemical reaction device which is a comparative example op ~ and the voltage V op ~ are obtained by solving the simultaneous equations of Equation (10).

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[0042] Also, in the case of the 4T-3PVK / 5Si-2EC type chemical reaction device which is another comparative example, the two types of cells of the PVK cell and the Si cell operate electrically independently. Therefore, by solving the equation corresponding to Equation (7), the current density J op PVK ~ of the PVK cell and the current density J op Si ~ of the Si cell are calculated. The sum of these current densities J op PVK ~ and the current density J op Si ~ becomes the overall current density J op ~. Here, A PVK :(1 - A PVK ) is the area ratio of the EC reactor connected to the PVK cell and the EC reactor connected to the Si cell. The conversion efficiency η of the reaction for the production of carbon monoxide (CO) by the reduction of carbon dioxide (CO2) CO is the weighted sum of the values calculated for each of the PVK cell and the Si cell.

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[0043] For each of the PVK and Si cells, the power generation characteristics expressed by equation (1) are set to a value close to the characteristics of the cell that yielded the highest conversion efficiency in “H. Min, DY Lee, J. Kim, G. Kim, KS Lee, J. Kim, MJ Paik, YK Kim, KS Kim, MG Kim, TJ Shin, and SI Seok, Nature 598, 444 (2021).”, “K. Yoshikawa, H. Kawasaki, W. Yoshida, T. Irie, K. Konishi, K. Nakano, T. Uto, D. Adachi, M. Kanematsu, H. Uzu, and Ki Yamamoto, Nat. Energy 2, 17032 (2017).”, and “M. Nakamura, K. Yamaguchi, Y. Kimoto, Y. Yasaki, T. Kato, and H. Sugimoto, IEEE J. Photovolt. 9, 1863 (2019).”, so that the external quantum efficiency η of the photoelectric conversion is set to a value close to the characteristics of the cell that yielded the highest conversion efficiency in “H. Min, DY Lee, J. Kim, G. Kim, KS Lee, J. Kim, MJ Paik, YK Kim, KS Kim, MG Kim, TJ Shin, and SI Seok, Nature 598, 444 (2021).”, EQE External luminous efficiency η ERE , series resistor r s The photoelectric conversion efficiency η at this time was determined. PV The calculation results are shown in Figure 6. The calculation results were in close agreement with the experimental results. Note that the current density j of the EC reactor for hydrogen (H2) production is... (EC) , current density j of the EC reactor for carbon monoxide (CO) generation (EC) and Faraday efficiency η FE“S. Wen, T. Yang, N. Zhao, L. Ma, and E. Liu, Appl. Catal. B: Environ. 258, 117953 (2019).” and “S. Verma, Y. Hamasaki, C. Kim, W. Huang, S. Lu, H.-RM Jhong, AA Gewirth, T. Fujigaya, N. Nakashima, and PJA, respectively. Kenis, ACS Energy Lett. 4, 193 (2018).”

[0044] Based on the above method, a predetermined operating voltage V op ~Operating current density J of PV module 100 op ~and conversion efficiency η STC The following calculations were performed. Figures 7 to 9 show the operating current density J when AM1.5G light is irradiated onto the PV module 100, respectively. op The calculation results for ~ are shown. In order to decompose water (H2O) and produce hydrogen (H2), a voltage V is usually required. op A voltage of ~=1.4V~1.6V is required. To reduce carbon dioxide (CO2) to produce carbon monoxide (CO) or formic acid (HCOOH), a voltage of V is usually required. op ~=1.6V~2.0V is required. Therefore, these voltages V op The operating current density J when ~ is applied op ~The number of PVK cells per EC reactor n in the above Example 3 PVK ~ and the number of SiCells n Si The calculation was performed as a function of ~. A PVK cell was used as the top cell 10, and the optimization was performed for each case under the constraint that the PVK cell's band gap must be 1.7 eV or less. A Si cell was used for the bottom cell 12.

[0045] As shown in Figure 7, a voltage V is used to decompose water (H2O) and produce hydrogen (H2). op Assuming ~=1.4eV, the number of PVK cells per EC reactor is n. PVK~ is between 1.1 and 1.8 and the number of Si cells n Si When ~ is between 2.0 and 3.0, the operating current density J is higher than in Comparative Example 1. op ~ was obtained. Also, as shown in Figure 8, a voltage V was used to reduce carbon dioxide (CO2) to produce carbon monoxide (CO) or formic acid (HCOOH). op Assuming ~=1.6eV, the number of PVK cells per EC reactor is n. PVK ~ is between 1.3 and 3.0, and the number of Si cells is n Si When ~ is between 2.3 and 4.0, the operating current density J is higher than in Comparative Example 1. op ~ was obtained. More preferably, the number of PVK cells per EC reactor is n. PVK ~ is between 1.3 and 1.6 and the number of Si cells n Si When ~ is between 2.3 and 3.0, an even higher operating current density J op ~ was obtained. Also, as shown in Figure 9, the voltage V op If ~=2.0eV, the number of PVK cells per EC reactor is n. PVK ~ is between 1.6 and 3.0 and the number of Si cells n Si When ~ is between 2.8 and 4.0, the operating current density J is higher than in Comparative Example 1. op ~ was obtained.

[0046] Figure 10(a) shows the operating current density J when AM1.5G light is irradiated onto the PV module 100. op ~ is voltage V op The results calculated as a function of ~ are shown. A PVK cell was applied to the top cell 10, and Si was applied to the bottom cell 12. Also, as shown in Figure 10(b), in Example 3, each voltage V op ~The number of PVK cells per EC reactor n PVK ~ and the number of SiCells n Si The optimal value of ~ was determined. In this process, the band gap Eg of the PVK cell was optimized for each case under the constraint of being 1.7 eV or less. Furthermore, as shown in Figure 10(c), the annual average value when the PV module 100 was irradiated with the actual outdoor solar spectrum (Tsukuba City, 2015) was also calculated. As a result, the voltage V opHigher operating current density J than Comparative Example 1 across the entire range op ~ was obtained.

[0047] Figure 11 shows the conversion efficiency of hydrogen (H2) production or carbon monoxide (CO) production when AM1.5G light is irradiated onto a chemical reaction device consisting of a PV module 100 connected to an EC module 102 for water electrolysis hydrogen production, or an EC module 102 for carbon dioxide decomposition carbon monoxide production. A Si cell or a CIGS cell was used as the bottom cell of the PV module 100. When using a CIGS cell, the Si values ​​in equations (1) to (11) were replaced with CIGS values. External quantum efficiency of photoelectric conversion η EQE External luminous efficiency η ERE , series resistor r s The values ​​were determined based on "M. Nakamura, K. Yamaguchi, Y. Kimoto, Y. Yasaki, T. Kato, and H. Sugimoto, IEEE J. Photovolt. 9, 1863 (2019)". In Figure 11, H2 is shown when the EC module 102 for water electrolysis hydrogen generation is applied, and CO is shown when the EC module 102 for carbon monoxide generation is applied. Furthermore, Si is shown when a Si cell is applied to the bottom cell of the PV module 100, and CIGS is shown when a CIGS cell is applied. In addition, the annual average value when irradiated with actual sunlight spectra measured outdoors (Tsukuba City, 2015) was also calculated.

[0048] As shown in Figure 11, higher conversion efficiencies were obtained in all of the following chemical reaction devices compared to Comparative Example 1: a chemical reaction device combining 5 PVK cells and 10 Si cells in 4 EC reactors (5PVK / 10Si-4EC), a chemical reaction device combining 7 PVK cells and 13 Si cells in 5 EC reactors (7PVK / 13Si-5EC), a chemical reaction device combining 5 PVK cells and 9 CIGS cells in 4 EC reactors (5PVK / 9CIGS-4EC), and a chemical reaction device combining 7 PVK cells and 13 CIGS cells in 5 EC reactors (7PVK / 13CIGS-5EC).

[0049] Figure 12(a) shows the calculated conversion efficiency when AM1.5G light is irradiated onto a chemical reaction device for water electrolysis hydrogen generation. The chemical reaction device for water electrolysis hydrogen generation was configured with 5 PVK cells and 10 Si cells connected to 4 EC reactors (5PVK / 10Si-4EC). The solid line represents the area ratio A of the EC reactors connected to the PVK cells in EC module 102 for Comparative Example 2, a 4-terminal tandem PV module + 2-split EC module (4T-PVK / 10Si-4EC). PVK This is the result calculated as a function of . In this case, the area ratio of the EC module connected to the Si cell, which is the bottom cell, is 1-A PVK The dashed line shows the results for the example 5PVK / 10Si-4EC. Figure 12(b) shows the annual average values ​​when the chemical reaction device is irradiated with the actual sunlight spectrum measured outdoors (Tsukuba City, 2015).

[0050] Figure 13(a) shows the calculated conversion efficiency when AM1.5G light is irradiated onto a chemical reaction device for carbon dioxide decomposition and carbon monoxide production. The chemical reaction device for carbon dioxide decomposition and carbon monoxide production was configured with 7 PVK cells and 13 Si cells connected to 5 EC reactors (7PVK / 13CIGS-5EC). The solid line represents the area ratio A of the EC reactors connected to the PVK cells in EC module 102 for Comparative Example 2, a 4-terminal tandem PV module + 2-split EC module (4T-7PVK / 13CIGS-5EC). PVK This is the result calculated as a function of . In this case, the area ratio of the EC module connected to the CIGS cell, which is the bottom cell, is 1-A PVK The dashed line shows the results for the example 7PVK / 13CIGS-5EC. Figure 13(b) shows the annual average values ​​when the chemical reaction device is irradiated with the actual sunlight spectrum measured outdoors (Tsukuba City, 2015).

[0051] In both the chemical reaction device for water electrolysis hydrogen production shown in Figure 12 and the chemical reaction device for carbon dioxide decomposition carbon monoxide production shown in Figure 13, the area ratio A in Comparative Example 4 was observed. PVK The same conversion efficiency as when the value is optimal was obtained.

[0052] [Structure of the present invention] Configuration 1: A chemical reaction device that supplies power from a photoelectric conversion module to an electrochemical module and uses that power to generate a chemical reaction, The aforementioned photoelectric conversion module, from the light-receiving surface side, A photoelectric conversion cell using a light-absorbing material with a band gap of 1.3 eV to 1.7 eV is n t A top cell module connected in series, A photoelectric conversion cell using a light-absorbing material with a band gap of 1.0 eV to 1.2 eV is n b A bottom cell module connected in series, This configuration involves stacking these components and connecting them in parallel. The electrochemical module has an electrochemical reactor n EC It is a configuration in which individuals are connected in series. n t / n EC n is 1.1 or greater, b / n EC A chemical reaction device characterized by having 2 or more. Configuration 2: A chemical reaction device as described in Configuration 1, The photoelectric conversion cell constituting the top cell module is a chemical reaction device characterized by being an organic-inorganic hybrid perovskite cell. Configuration 3: A chemical reaction device according to configuration 1 or 2, The chemical reaction device is characterized in that the photoelectric conversion cell constituting the bottom cell module is a crystalline silicon cell or a Cu(in,Ga)Se2 cell. Configuration 4: A chemical reaction device described in any one of configurations 1 to 3, The electrochemical reactor is a chemical reaction device characterized by producing hydrogen (H2) and oxygen (O2) from water (H2O). Configuration 5: A chemical reaction device relating to configuration 4, n t / n EC n is between 1.1 and 1.8, b / n EC A chemical reaction device characterized by having a value between 2.0 and 3.0. Configuration 6: A chemical reaction device described in any one of configurations 1 to 3, The electrochemical reactor is a chemical reaction device characterized by producing carbon monoxide (CO) or formic acid (HCOOH) from carbon dioxide (CO2) and water (H2O). Composition 7: A chemical reaction device relating to configuration 6, n t / n EC n is between 1.3 and 3.0, b / n EC A chemical reaction device characterized by having a value between 2.3 and 4.0. Composition 8: A chemical reaction device described in any one of configurations 1 to 3, The electrochemical reactor is a chemical reaction device characterized by reducing carbon dioxide (CO2). [Explanation of Symbols]

[0053] 10 top cells, 12 bottom cells, 14 EC reactors, 100 PV modules, 102 EC modules.

Claims

1. A chemical reaction device that supplies power from a photoelectric conversion module to an electrochemical module and uses that power to generate a chemical reaction, The aforementioned photoelectric conversion module, from the light-receiving surface side, A photoelectric conversion cell using a light-absorbing material with a band gap of 1.3 eV to 1.7 eV is used. ｔ A top cell module connected in series, A photoelectric conversion cell using a light-absorbing material with a band gap of 1.0 eV to 1.2 eV is constructed. ｂ A bottom cell module connected in series, This configuration involves stacking these components and connecting them in parallel. The electrochemical module has an electrochemical reactor n ＥＣ It is a configuration in which individuals are connected in series. The electrochemical reactor generates hydrogen (H₂) and oxygen (O₂) from water (H₂O), n ｔ / n ＥＣ n is between 1.1 and 1.8, ｂ / n ＥＣ A chemical reaction device characterized in that the coefficient is between 2 and 3.

0.

2. A chemical reaction device that supplies power from a photoelectric conversion module to an electrochemical module and uses that power to generate a chemical reaction, The aforementioned photoelectric conversion module, from the light-receiving surface side, A photoelectric conversion cell using a light-absorbing material with a band gap of 1.3 eV to 1.7 eV is used. ｔ A top cell module connected in series, An optoelectronic conversion cell using a light absorption material having a band gap of 1.0 eV or more and 1.2 eV or less is n ｂ bottom cell modules connected in series, and This configuration involves stacking these components and connecting them in parallel. The electrochemical module has an electrochemical reactor n ＥＣ It is a configuration in which individuals are connected in series. The electrochemical reactor generates carbon monoxide (CO) or formic acid (HCOOH) from carbon dioxide (CO₂) and water (H₂O), n ｔ / n ＥＣ n is between 1.3 and 3.0, ｂ / n ＥＣ A chemical reaction device characterized by having a value between 2.3 and 4.

0.

3. A chemical reaction device according to claim 1 or 2, The photoelectric conversion cell constituting the top cell module is a chemical reaction device characterized by being an organic-inorganic hybrid perovskite cell.

4. A chemical reaction device according to claim 1 or 2, The photoelectric conversion cell constituting the bottom cell module is a crystalline silicon cell or Cu(in,Ga)Se ２ A chemical reaction device characterized by being a cell.

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