Electrified Cement Production via Anion-Mediated Electrochemical Calcium Extraction

Cement production is a carbon-intensive industrial process, with the sector contributing ∼8% of global anthropogenic CO₂ emissions. On average, producing each kilogram of cement leads to the emission of 1 kg of CO₂─the combination of fuel combustion emissions and carbon released from the feedstock, limestone (CaCO₃). Here we report electrochemical cement production based on anion-mediated electrochemical calcium extraction (ECE) that addresses both feedstock and energy emissions. The in situ-generated acidic electrolytes release the feedstock CO₂ emissions at high purity, enabling direct carbon utilization or sequestration without costly capture and purification steps. Energy embodied within a separate H₂ output stream is sufficient to sinter Ca(OH)₂ to produce portland cement, thus removing the CO₂ emissions associated with fuel combustion. We then replace CaCO₃ with a carbon-free calcium feedstock, gypsum, thereby removing the CO₂ emissions embodied in the feedstock. Technoeconomic analysis forecasts that this method could provide a viable, decarbonized cement alternative.