Assessing the economic potential of large-scale carbonate-formation-free CO2 electrolysis

Abstract

Electrochemical CO₂ reduction is a potential approach to manufacture carbon-neutral fuels and chemicals. To deploy CO₂ electrolysis in the practical production of fuels and chemicals, energetically efficient electrolyzers are required. However, carbonate formation and the consequent CO₂ crossover from cathodes to anodes cause unacceptable energy consumption, making the cost of CO₂ electroreduction lower than the threshold for economic viability. Herein, we provide quantitative analyses of the impact of carbonate formation on the costs of CO₂ electroreduction products. Using the electrosynthesis of alcohols and ethylene as examples, we conducted techno-economic assessments (TEAs) and found that carbonate formation impacts the production costs of alcohols and ethylene by altering the costs of the electrolyzer, CO₂, and separation. Solving the carbonate formation issue reduces the production cost by 744–1696 USD per tonne, nearly equal to the market prices of the products. Finally, we conclude that inhibiting carbonate formation, together with improving reaction selectivity and productivity, would decrease the production costs by more than 90%.