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JP-7855934-B2 - Chemical reaction devices

JP7855934B2JP 7855934 B2JP7855934 B2JP 7855934B2JP-7855934-B2

Inventors

  • 竹田 康彦
  • 山中 健一
  • 加藤 直彦

Assignees

  • 株式会社豊田中央研究所

Dates

Publication Date
20260511
Application Date
20220608

Claims (4)

  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 top cell module comprising n t photoelectric conversion cells connected in series, each using a light-absorbing material with a band gap of 1.3 eV to 1.7 eV, A bottom cell module comprising n b photoelectric conversion cells connected in series, each using a light-absorbing material with a bandgap of 1.0 eV to 1.2 eV, This configuration involves stacking these components and connecting them in parallel. The electrochemical module has a configuration in which n electrochemical reactors are connected in series . The electrochemical reactor generates hydrogen (H₂) and oxygen (O₂) from water ( H₂O ) , A chemical reaction device characterized in that n t / n EC is 1.1 or more and 1.8 or less , and n b / n EC is 2 or more and 3.0 or less .
  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 top cell module comprising n t photoelectric conversion cells connected in series, each using a light-absorbing material with a band gap of 1.3 eV to 1.7 eV, A bottom cell module comprising n b photoelectric conversion cells connected in series, each using a light-absorbing material with a bandgap of 1.0 eV to 1.2 eV, This configuration involves stacking these components and connecting them in parallel. The electrochemical module has a configuration in which n electrochemical reactors are connected in series . The electrochemical reactor generates carbon monoxide (CO) or formic acid (HCOOH) from carbon dioxide ( CO₂) and water ( H₂O ), A chemical reaction device characterized in that n t / n EC is 1.3 or more and 3.0 or less , and n b / n EC is 2.3 or more and 4.0 or less .
  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 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.

Description

This invention relates to a chemical reaction device. 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 ( H₂O ) from water ( H₂O ), and carbon monoxide ( CO ) and formic acid (HCOOH) from carbon dioxide (CO₂) and water ( H₂O ). In the current state of artificial photosynthesis technology, a combination of a photoelectric (PV) cell and an electrochemical (EC) reactor has been shown to achieve higher conversion efficiency (η STC ) from solar energy to chemical energy compared to methods using photocatalysts. 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 practically meaningful reaction rate, an applied voltage of at least 1.6V to 1.8V is required, which is an overvoltage added to these values. Therefore, in order to increase the conversion efficiency (η STC ) from solar energy to chemical energy, PV cells with two junctions (2J) or three junctions (3J) are currently used. Furthermore, to address the problems of the 2J-PV cells and 3J-PV cells described below, a configuration has been proposed using a 4-terminal tandem PV module, 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 bandgap than those used in the top module, are stacked with the top PV module facing upwards (light-irradiating side), and each is connected to a separate EC reactor (Non-Patent Document 1). R. T. White, et al., J. Mater. Chem. A 5, 13112 (2017) This figure shows the configuration of the chemical reaction device in Example 1 of the present invention.This figure shows the configuration of the chemical reaction device in Example 2 of the present invention.This figure shows the configuration of the chemical reaction device in Example 3 of the present invention.This figure shows the configuration of the chemical reaction device in Comparative Example 1.This figure shows the configuration of the chemical reaction device in Comparative Example 2.This figure shows the calculated results and measured values of various characteristics of the photoelectric conversion cell.This figure shows the calculation results of the operating current density J op ~ in an embodiment of the present invention.This figure shows the calculation results of the operating current density J op ~ in an embodiment of the present invention.This figure shows the calculation results of the operating current density J op ~ in an embodiment of the present invention.This figure shows the calculation results of the optimal values for the operating current density Jop ~, the number of PVK cells n PVK ~, and the number of Si cells n Si ~ , 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.This figure shows the calculation results of the conversion efficiency in an embodiment of the present invention.This figure shows the calculation results of the conversion efficiency relative to the area ratio A of the EC reactor connected to the PVK cell for the chemical reaction device for water electrolysis hydrogen generation of the present invention.This figure shows the calculated conversion efficiency of the EC reactor connected to the PVK cell, relative to the area ratio A of the PVK cell, for the carbon dioxide decomposition carbon monoxide generation chemical reaction device of the present invention. 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 combines a top cell 10 and a bottom cell 12, is connected to an electrochemical (EC) module 102. 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 varies depending on its composition, but for example, a band gap Eg of 1.2 eV to 1.7 eV is preferable. Currently, the best photoelectric conversion efficiency ( ηPV ) is obtained in about 25% of compositions where the band gap Eg = 1.5 eV. 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. For example, a Si cell has a band gap Eg of 1.12 eV and has achieved a maximum photoelectric