Power-to-liquids - Conversion of CO 2 and Renewable H 2 to methanol

To achieve targets set out in national and international frameworks (e.g. COP21-23, German "Energiewende", etc .), the contribution of renewable energies (RE; e.g. solar, wind, tidal, etc .) to the energy system must dramatically increase. However RE adoption as the main contributor to national supply (e.g. aims of > 80% in Germany by 2050) faces a number of challenges, not least regarding matching supply and demand from these typically intermittent sources (e.g. at the > GW scale). One option is to store this electrical energy in the form of chemical bonds, for example through the production of liquid energy carriers - an approach often referred to as "Power-to-Liquid". The resulting "liquid storage" molecules, for example methanol, have higher energy densities than more classical technologies (e.g. batteries) and can be stored on very large scale, in some cases without significant alteration to existing infrastructure. As discussed in this chapter, H 2 produced via water splitting (e.g. electrolysis) can be used in the catalytic hydrogenation (over Cu/ZnO-based catalysts) of CO 2 (e.g. captured from industry) to produce CH 3 OH. This C1 alcohol in turn is a suitable platform for the chemical industry (e.g. to produce formaldehyde) and the production of mobility fuels (e.g. dimethyl ether, oxymethylene ethers, synthetic kerosene etc .). This chapter provides an overview of endeavours and technologies associated with the elaboration of methanol production through a Power-to-Liquid approach. Falling under the generic umbrella of carbon capture and utilisation, and echoing previous propositions of Asinger and Olah, the establishment of Power-to-Liquid systems for methanol production will be underpinned by an ever increasing integration of the energy and chemical sectors. This in turn will lay the basis for the establishment of sustainable, circular economies based on the recycling of waste greenhouse gases and renewable energy; transforming one sectors waste liability to an asset and platform for another.