Electrochemical transformation of limestone into calcium hydroxide and valuable carbonaceous products for decarbonizing cement production

Summary: The cement industry is one of the largest contributors to global CO2 emissions, which has been paid more attention to the research on converting the CO2 released by the cement production process. It is extremely challenging to decarbonize the cement industry, as most CO2 emissions result from the calcination of limestone (CaCO3) into CaO and CO2. In this work, we demonstrate an in situ electrochemical process that transforms CaCO3 into portlandite (Ca(OH)2, a key Portland cement precursor) and valuable carbonaceous products, which integrates electrochemical water splitting and CO2 reduction reaction with the chemical decomposition of CaCO3. With different metal catalyst electrodes (like Au, Ag, In, Cu, and Cu nanowires electrodes), we have achieved various valuable carbonaceous products, such as CO, formate, methane, ethylene, and ethane during the electrochemical CO2 process. Our work demonstrates a proof of concept for green and sustainable cement production.