Toward electrochemical synthesis of cement—An electrolyzer-based process for decarbonating CaCO₃ while producing useful gas streams
Name
1821673116.full.pdf
Description
Published version
Size
2.42 MB
Format
Adobe PDF
Checksum (MD5)
8b6f8f7f06a0f0bbd1bf4077a4eecd97
Author(s)
Ellis, Leah D.
Badel, Andres F.
Chiang, Miki L.
Park, Richard J.-Y.
Chiang, Yet-Ming
Date Issued
September 16, 2019
Journal
Proceedings of the National Academy of Sciences of the United States of America
Publisher
Proceedings of the National Academy of Sciences
Citation
Ellis, Leah D. et al. "Toward electrochemical synthesis of cement—An electrolyzer-based process for decarbonating CaCO₃ while producing useful gas streams." Proceedings of the National Academy of Sciences of the United States of America 2019: 1821673116 © 2019 The Author(s)
Version
Final published version
Abstract
Cement production is currently the largest single industrial emitter of CO₂, accounting for∼8% (2.8 Gtons/y) of global CO₂ emissions.Deep decarbonization of cement manufacturing will require remediation of both the CO₂ emissions due to the decomposition of CaCO₃ to CaO and that due to combustion of fossil fuels (primarily coal) in calcining (∼900 °C) and sintering (∼1,450 °C). Here, we demonstrate an electrochemical process that uses neutral water electrolysis to produce a pH gradient in which CaCO₃is decarbonated at low pH and Ca(OH)₂ is precipitated at high pH, concurrently producing a high-purity O₂/CO₂ gas mixture (1:2 molarratio at stoichiometric operation) at the anode and H₂ at the cathode. We show that the solid Ca(OH)₂ product readily decomposes and reacts with SiO₂ to form alite, the majority cementitious phasein Portland cement. Electrochemical calcination produces concentrated gas streams from which CO₂ may be readily separated and sequestered, H₂ and/or O₂ may be used to generate electric power via fuel cells or combustors, O₂ may be used as a component ofoxyfuel in the cement kiln to improve efficiency and lower CO₂ emissions, or the output gases may be used for other value-added processes such as liquid fuel production. Analysis shows that if the hydrogen produced by the reactor were combusted to heat the high-temperature kiln, the electrochemical cement process could be powered solely by renewable electricity.
Subjects
Multidisciplinary
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
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DOI of Published Version
https://doi.org/10.1073/pnas.1821673116
