Methanol production from CO2: comparison of theenvironmental impact of different processes

Methanol is the simplest organic alcohol and one of the most important substances in industrial chemistry. It is used as fuel, solvent and starting material to produce formaldehyde, methyl-tertbutyl ether (MTBE), acetic acid and dimethyl-ether (DME). On industrial scale it is produced using a gas mixture of H2 and CO, also called syngas, in presence of a copper-based catalyst. Today methanol is primarily produced using fossil fuels. To improve the environmental impact new processes were developed during the years starting from different raw materials (i.e. biomass) or using different processes (i.e. photocatalysis). In this paper the environmental impact of different processes for the methanol production is evaluated using the Life Cycle Assessment (LCA) procedure. Relevant publications were reviewed focusing only on the environmental impact, while economical and social analysis were excluded.