Project CLEAN 4G will build upon a sustainable approach to the production of methane (SNG) from CO₂ and hydrogen based on renewable sources. This project will reinforce the relationship between a large CO₂ emitter and the renewable energy network, nationwide. The production and distribution of methane benefit from the already existing natural gas infrastructure, thus meaning its distribution will not involve additional CO₂ emissions usually associated with liquefaction and transportation.

This project presents two distinct research pathways with the same goal: obtaining methane. The pathways correspond to two different processes, one of CO₂ methanation and another of bio-crude external oxidation through bubbling of a mixture of gases (O₂,H₂ and CO₂).

Due to the high CO₂ emissions of the concrete production plant CMP, the installation of this kind of CO₂ conversion units will allow the use of the obtained methane as a fuel in the already existing process, by re-injecting it in the concrete plant and contributing for both the global decrease in gas emissions and a decrease in energy costs. A certain cycle of CO₂ emission and re-use is thus created.