Abstract: Carbon dioxide electrolysis apparatus includes: electrolysis stack having diaphragm including anion exchange type solid polymer electrolyte membrane and anode and cathode separated by diaphragm; carbon dioxide supply unit configured to supply carbon dioxide to gas flow path provided adjacent to cathode; power supply unit configured to supply electric power to stack; voltage sensor configured to detect stack voltage; temperature sensor configured to detect stack temperature; and control unit including processor and memory and configured to control power supply unit. Control unit controls power supply unit so that stack voltage becomes equal to or lower than upper limit value of stack voltage predetermined corresponding to stack temperature based on stack voltage detected by voltage sensor and stack temperature detected by temperature sensor during startup period until stack temperature reaches predetermined temperature after starting supply of electric power from power supply unit to stack.

Abstract: CO2 electrolysis apparatus includes: electrolysis stack configured to perform electrolysis using electric power generated by renewable energy; CO2 supply unit configured to supply CO2 to electrolysis stack; first storage unit configured to store first gas generated by electrolysis in electrolysis stack when CO2 is supplied; second storage unit configured to store second gas generated by electrolysis in electrolysis stack when supply of CO2 is stopped; reactor to which first and second gas stored in first and second storage unit are guided; voltage sensor configured to detect voltage of electrolysis stack; and control unit including processor and memory and configured to control CO2 supply unit to supply CO2 to electrolysis stack when detected voltage exceeds predetermined value and configured to control CO2 supply unit to stop supply of CO2 when detected voltage is equal to or less than predetermined value.

Abstract: A gas concentrating method and a gas concentrating device in which a large-capacity storage tank is not required and power consumption can be minimized are provided.