An experimental study aiming at reusing CO2 and implementing a validated laboratory technology based on a prototype methanation reactor (ProGeo) producing carbon neutral methane through the chemical conversion of CO2 waste flue gases using renewable energy in a circular economy scheme, is presented. ProGeo is able to produce a CH4 flux of 1 Nm(3)/h, using the Sabatier reaction at high pressure (1.5-3 bar) and temperature (200-400 degrees C) with a solid phase catalyst. Furthermore, the investigation of a new methanation pathway by exploring mechanisms involving a plasma generation by electrical discharges on CO2+H-2 gas mixtures has been undertaken. Obtained results indicate the formation of hydrocarbons as methane, formic acid and/or dimethyl ether as well as small amounts of HCO+, H2CO+, H3CO+, HCO2+ ions. These ionic species together with CO+ and O+ ions, having a very high kinetic energy content, should increase the chemical reactivity of generated plasmas playing a pivotal role in the plasma-assisted CO2 conversion on CH4 fuel. Further experimental work is in progress to optimize the experimental conditions of the CO2 methanation process via alternative microscopic mechanisms, using plasma assisted catalyzed reactions that are of great importance in new emerging catalysts development in chemical engineering.