Electrified Cement Production via Anion-Mediated Electrochemical Calcium Extraction
Rui Kai Miao, Ning Wang, Sung‐Fu Hung, Wen‐Yang Huang, Jinqiang Zhang, Yong Zhao, Pengfei Ou, Sasa Wang, Jonathan P. Edwards, Cong Tian, Jingrui Han, Yi Xu, Mengyang Fan, Jianan Erick Huang, Yurou Celine Xiao, Alexander H. Ip, Hongyan Liang, Edward H. Sargent, David Sinton
Abstract
Cement production is a carbon-intensive industrial process, with the sector contributing ∼8% of global anthropogenic CO 2 emissions. On average, producing each kilogram of cement leads to the emission of 1 kg of CO 2 ─the combination of fuel combustion emissions and carbon released from the feedstock, limestone (CaCO 3 ). 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 CO 2 emissions at high purity, enabling direct carbon utilization or sequestration without costly capture and purification steps. Energy embodied within a separate H 2 output stream is sufficient to sinter Ca(OH) 2 to produce portland cement, thus removing the CO 2 emissions associated with fuel combustion. We then replace CaCO 3 with a carbon-free calcium feedstock, gypsum, thereby removing the CO 2 emissions embodied in the feedstock. Technoeconomic analysis forecasts that this method could provide a viable, decarbonized cement alternative.