The cement industry is one of the largest contributors to global CO 2 emissions, which has been paid more attention to the research on converting the CO 2 released by the cement production process. It is extremely challenging to decarbonize the cement industry, as most CO 2 emissions result from the calcination of limestone (CaCO 3 ) into CaO and CO 2 . In this work, we demonstrate an in situ electrochemical process that transforms CaCO 3 into portlandite (Ca(OH) 2 , a key Portland cement precursor) and valuable carbonaceous products, which integrates electrochemical water splitting and CO 2 reduction reaction with the chemical decomposition of CaCO 3 . 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 CO 2 process. Our work demonstrates a proof of concept for green and sustainable cement production.
Cement production is one of the largest industrial sources of CO 2 emissions due to the thermal decomposition of limestone (CaCO 3 ). We integrate the chemical engineering strategy into the cement production and propose a novel process of “Carbonate Dry Reforming of Methane (CaDRM)” that converts the limestone (CaCO 3 ) directly into the cement clinker precursor (CaO) and syngas (CO + H 2 ) through reacting with methane (CH 4 ). Thermodynamic analysis indicates the reaction temperature of CaDRM is lowered by at least 200 °C compared with CaCO 3 thermal decomposition. Lab-scale experimental studies show a 95 % CaO yield at a 91 % syngas selectivity and 90 % CH 4 conversion in CaDRM using cement raw meal at 700 °C. Process simulation scale-up and economic analysis indicate CaDRM pathway can reduce 37.2 % CO 2 emission in comparison with the conventional CaCO 3 thermal decomposition pathway. More significantly, the net profit of $271.0/t (clinker) can be achieved by the value-added syngas products and the energy saving. The economic and environmental benefits of the proposed CaDRM strategy can help its future commercial deployment.
危险品化学品经营许可证（带存储）