Cement clinker precursor production in an electrolyser

• Published in: Energy & environmental science 2022-12, Vol.15 (12), p.5129-5136
• Main Authors: Zhang, Zishuai, Mowbray, Benjamin A. W, Parkyn, Colin T. E, Waizenegger, Chris, Williams, Aubry S. R, Lees, Eric W, Ren, Shaoxuan, Kim, Yongwook, Jansonius, Ryan P, Berlinguette, Curtis P
• Format: Article
• Language: English
• Subjects: Calcium carbonate; Calcium hydroxide; Carbon dioxide; Cement; Clinker; Current efficiency; Electrochemistry; Emissions; Life cycle analysis; Limestone; Manufacturing industry; Portland cement; Portland cements; Precursors; Slaked lime
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/d2ee02349k

The manufacture of cement is the single largest industrial source of CO 2(g) emissions into the atmosphere. We report here an electrochemical flow reactor (electrolyser) that continuously converts limestone (CaCO 3(s) ) into Ca(OH) 2(s) at a high rate of product formation (486 mg h −1 at 100 mA cm −2 ). The Ca(OH) 2(s) product (slaked lime) is a chemical precursor to cement clinker, the main component of Portland cement, and other cement varieties. This three-compartment electrolyser operates with ∼100% current efficiency at a cell voltage of 2.9 V and generates pure O 2(g) , H 2(g) , and CO 2(g) streams that can be utilized downstream without purification. To demonstrate this feature, we feed the CO 2(g) released from limestone directly to a second electrolyser that valorizes CO 2(g) into higher value carbon-containing products ( e.g. , CO). A preliminary life-cycle analysis indicates that the proposed electrochemical process can decrease the amount of CO 2 emitted per tonne of cement by 75% and achieve cost-parity with incumbent cement manufacturing processes. We report here an electrochemical flow reactor that converts limestone (CaCO 3(s) ) into Ca(OH) 2(s) at a high production rate and co-produces pure CO 2(g) .