Solar Gas - Wind Gas Project
The project, developed by the University of Perugia, proposes the reuse of CO2 (capture and storage) from fossil sources, output from CHP or as in the case study, from the system for upgrading of the methane.
It has the direct production of methane by use of CO2 and hydrogen (H2) by the reaction of Sabatier:
CO2 + 4H2 ⇒ CH4 + 2H2O
The reaction takes place at temperatures between 250-400 °C and using a metal catalyst, is lightly exothermic and therefore easily sustainable from the thermal point of view.
The central point is the supply source for hydrogen. The technology in question uses the surplus of renewable electricity (solar photovoltaic or wind power) in the hours of low demand to split water (electrolysis) and produce electrolytic H2. Once the hydrogen product, it is used for the reaction of Sabatier that provides CH4 and H2O. The methane is purified and, for example, injected into the network.
Interfacing the biomethane system with the production and utilization of hydrogen allows increase yields in methane and use the CO2 removed from the biogas, making the project even more sustainable.