In view of the desire to reduce the use of fossil fuels and nuclear energy, the massive use of renewable energies for our energy needs has become a necessity. It is now becoming urgent to provide a response to the intermittency of certain renewable energies (wind and solar) in order to store excess production and respond to subsequent consumption peaks. The energy produced in this way must be stored in another form in order to avoid losses and ensure continuity of supply, particularly for electricity. This is known as Power-to-X, where Power is the energy produced and X is the medium used to store it pending consumption.

In this strategy, the production of energy carriers such as H2 is essential, hence the numerous projects involving the development of water electrolysis technology up to pilot production sites. Thus a fraction of the electrical surplus is consumed for the production of H2 by electrolysis: this is called Power-to-Gas (the vector produced, H2, being a gas). The difficulty of storing H2 remains a limiting factor in the medium to long term. In this perspective, various transformations are envisaged. The methanation reaction, by reaction between H2 and CO2, is a particularly attractive option, as the product is 100% miscible with natural gas and can therefore be injected directly into existing distribution networks. Many sources of recoverable CO2 exist: CO2 from biogas or syngas (biomass gasification) purification processes, CO2 capture from industrial emissions (particularly from cement, petrochemical and metallurgical processes) and emissions linked to electricity production (combustion production sites).