Pathways to Industrial-Scale Fuel Out of Thin Air from CO2 Electrolysis

The use of CO2, water, and renewable electricity as direct feedstocks for the synthesis of chemicals and fuels is a seemingly appealing means of transitioning away from a reliance on fossil fuels. Electrochemical CO2 reduction in particular has been championed as a technology aiding in the energy transition. Despite continuous technical improvements, however, the consideration of CO2 electrolyzers within a chemical process remains largely unaddressed. Given the need to capture CO2 prior to electrochemical conversion, upconvert most CO2 reduction products, and operate on renewable electricity, it is essential that we start thinking about CO2 electrolyzers as part of a larger system, rather than as an independent technology. In other words, what is the endgame for CO2 electrolyzers? To initiate these discussions within the CO2 reduction community, we considered the use of CO2 electrolyzers as one technology in the air-to-barrel'' production of 10,000 tons of methanol/day. Looking at the role of the CO2 electrolyzers in the process, we highlight the distribution of energy resources required, the potential for process integration, and the importance of increasing current densities even further. A key conclusion finds that a six order-of-magnitude gap exists between current catalyst areas and industry-sized applications, emphasizing the need to begin research on scaling CO2 catalysts and electrolyzers immediately if they are to contribute to the upcoming energy transition.