Carbon dioxide is used as a reactive in some very few reactions like in the synthesis of urea, salicylic acid and carbonates. Nowadays, with the growing concern for the environment about the global warming and the rise in the emissions of CO2, all the utilization of CO2 as a reactive trends to the reduction of its emissions to the atmosphere. Production of Methane or liquid hydrocarbures using hydrogen and CO2, obtained from the vapor gasification of biomass, represents a viable option for energy production from non fossil fuels. Methanation from syngas is made using a Raney-Nickel catalyst. Deactivation and leaching of the active phase do to the presence of water and CO in the feed mixture has lead to the study of new catalysts and alternatives: the adding of noble metals for increasing the reactivity; the conversion of CO into CO2 and the separation of water before the methanation.