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 product 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 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%.