Invention presents a method of increasing the CO to H.sub.2 ratio of syngas. The method comprises passing syngas over a first rector (10) containing Cu at a first temperature effective for the reaction of CO.sub.2 within the syngas with the Cu to form copper oxide and CO. The temperature of the syngas is then reduces to a second temperature effective for the for the reaction of hydrogen within the syngas with copper oxide to form Cu and H.sub.2O. The syngas is then passed over a second rector (12) containing copper oxide so that the H.sub.2 within the syngas reacts with the copper oxide.

A methane synthesis system according to the present disclosure includes: a co-electrolysis part that obtains hydrogen and carbon monoxide by electrolyzing water and carbon dioxide, a methanation reaction part that obtains a product gas containing methane by a methanation reaction that uses the hydrogen and the carbon monoxide, and a cooler having a distribution channel in which a refrigerant capable of phase transition, is distributed. The cooler cools the methanation reaction part using heat of vaporization from vaporizing at least a portion of the refrigerant on an inside of the distribution channel.

A methane generation system according to the present disclosure includes a water supply path that supplies water or water vapor, a carbon dioxide supply path that supplies carbon dioxide, a power supply path that supplies power, an SOLO co-electrolysis device to which the water supply path, the carbon dioxide supply path and the power supply path are connected, a methane reactor, a connection path that connects the SOEC co-electrolysis device and the methane reactor, and a first heat exchange section that performs heat exchange between the SOEC co electrolysis device and the methane reactor.

The present disclosure relates to a hydrogen reforming system including a reforming part configured to produce a reformed gas containing hydrogen by allowing a source gas and pure water to react with each other, a source gas supply line connected to the reforming part and configured to supply the source gas, a pure water supply line connected to the source gas supply line and configured to supply the pure water, a discharge line configured to discharge the reformed gas from the reforming part, and a heating part configured to selectively heat at least any one of the source gas and the pure water. The source gas and the pure water are to be supplied to the reforming part by using waste heat of the reformed gas discharged from the reforming part, thereby obtaining an advantageous effect of improving stability, reliability, and reforming efficiency.