Elevating CO2 electrolyzer temperature accelerates the viability of chemical electrification

Abstract

Climate change mitigation has spurred interest in producing chemicals from CO2. CO2 reduction by electrochemistry can be driven directly by green electricity, yielding even multi-carbon (C2+) products. However, the resulting processes still suffer from high electrolyzer losses and substantial energy demands. This study evaluates the environmental and economic benefits of integrating optimized electrolyzers into complete processes. For CO2 electroreduction to ethylene and dimerization to 1-butene, elevated-temperature electrolysis effectively utilizes waste heat. Challenging the ambient-temperature paradigm, this strategy achieves system-wide savings in energy (10%), climate impacts (9%) and overall cost (11%). Generalizing these findings across various CO2 electroreduction pathways identifies energy savings of up to 25% and the heating system as a key design variable affecting electrolyzer design targets. Our study demonstrates how process integration can guide CO2 electrolyzer development toward sustainable processes. Unlocking the full potential of CO2 electroreduction requires looking beyond ambient-temperature operation. By integrating elevated-temperature electrolysis to capture waste heat, this study highlights opportunities for substantial process-wide savings in energy, climate change impacts and cost. Ultimately, this study demonstrates how system-level integration guides the design of scalable, sustainable chemical production.