Abstract: A gas production device that makes it possible to raise the temperature of a reaction unit by separating a removal unit from a reactor. The device has at least two reactors and a removal unit. The two reactors are connected in series and are configured to supply an oxidizing gas containing carbon dioxide, and a reducing gas containing a reducing substance. Each of the reactors accommodates a metal and/or a metal oxide which promotes reduction of the carbon dioxide or the reaction between the carbon dioxide and the reducing substance, thereby generating a valuable carbon substance. The removal unit is connected between the two reactors and has a phase separation mechanism that carries out phase separation of a gaseous component and a separated component including at least one of a liquid component and a solid component produced through cooling, thereby removing products derived from the gas supplied to the reactors.

Abstract: Provided are a gas production apparatus (that is, an industrially advantageous gas production apparatus), a gas production system, and a gas production method that can easily and accurately determine the timing to end a reaction and can operate stably. A gas production apparatus 1 includes: reactors 4a and 4b each of which includes a container 41 through which a substrate gas is capable of passing and a reducing agent layer (packed bed) 42 with which the container 41 is filled and which includes a metal oxide that exchanges oxygen elements with the substrate gas by an exothermic reaction or an endothermic reaction; and a plurality of temperature sensors 4T1 to 4T4 that are connected to each of the reactors 4a and 4b and measure temperatures of a plurality of measurement points of the packed bed 42 along a passage direction of the substrate gas, respectively.

Abstract: A gas production device 1 comprises a connection unit 2 for supplying an exhaust gas including carbon dioxide CO2, a reducing gas supply unit 3 that supplies a reducing gas including H2 that reduces a reducing agent 4R that has been brought into an oxidized state by contact with the carbon dioxide CO2, the reducing agent including a metal oxide that generates CO by reducing the carbon dioxide CO2, and a reaction unit 4 provided with a plurality of reactors 4a to 4d connected respectively to the connection unit 2 and the reducing gas supply unit 3, and with the educing agent 4R that is contained in each of the reactors 4a to 4d, in which the reaction unit 4 being capable of switching between the oxidizing gas and the reducing gas to be supplied to each of the reactors 4a to 4d.