Madeddu, S., Priestnall, M., Godoy, E. et al. (6 more authors) (2015) Extraction of Mg(OH)2 from Mg silicate minerals with NaOH assisted with H2O: implications for CO2 capture from exhaust flue gas. Faraday Discussions, 183. pp. 369-387. ISSN 1359-6640
Abstract
The utilisation of Mg(OH)2 to capture exhaust CO2 has been hindered by the limited availability of brucite, the Mg(OH)2 mineral in natural deposits. Our previous study demonstrated that Mg(OH)2 can be obtained from dunite, an ultramafic rock composed of Mg silicate minerals, in highly concentrated NaOH aqueous systems. However, the large quantity of NaOH consumed was considered an obstacle for the implementation of the technology. In the present study, Mg(OH)2 was extracted from dunite reacted in solid systems with NaOH assisted with H2O. The consumption of NaOH was reduced by 97% with respect to the NaOH aqueous systems, maintaining a comparable yield of Mg(OH)2 extraction, i.e. 64.8–66%. The capture of CO2 from a CO2–N2 gas mixture was tested at ambient conditions using a Mg(OH)2 aqueous slurry. Mg(OH)2 almost fully dissolved and reacted with dissolved CO2 by forming Mg(HCO3)2 which remained in equilibrium storing the CO2 in the aqueous solution. The CO2 balance of the process was assessed from the emissions derived from the power consumption for NaOH production and Mg(OH)2 extraction together with the CO2 captured by Mg(OH)2 derived from dunite. The process resulted as carbon neutral when dunite is reacted at 250 °C for durations of 1 and 3 hours and CO2 is captured as Mg(HCO3)2.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2015 The Royal Society of Chemistry. This is an author produced version of a paper subsequently published in Faraday Discussions. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 04 Oct 2016 15:14 |
Last Modified: | 23 Mar 2018 11:55 |
Published Version: | http://dx.doi.org/10.1039/c5fd00047e |
Status: | Published |
Publisher: | Royal Society of Chemistry |
Refereed: | Yes |
Identification Number: | 10.1039/c5fd00047e |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:105445 |