Molinder, R, Comyn, TP, Hondow, N et al. (2 more authors) (2012) In situ X-ray diffraction of CaO based CO2 sorbents. Energy and Environmental Science, 5 (10). 8958 - 8969. ISSN 1754-5692
Abstract
In situ X-ray diffraction coupled with Rietveld refinement has been used to study CO2 capture by CaO, Ca(OH)2 and partially hydrated CaO, as a function of temperature. Phase quantification by Rietveld refinement was performed to monitor the conversion to CaCO3 and the results were compared to those derived using thermogravimetric analysis (TGA). It was found that Ca(OH)2 converted directly to 100% CaCO3 without the formation of a CaO intermediate, at ca. 600 °C. Both pure CaO and partially hydrated CaO (33.6 wt% Ca(OH)2) reached the same capture capacity, containing approximately 65 wt% CaCO3 at 800 °C. It was possible to provide direct evidence of the capture mechanism. The stresses in the Ca(OH)2 phase of the partially hydrated CaO were found to be more than 20 times higher than its strength, leading to disintegration and the generation of nano-sized crystallites. The crystallite size determined using diffraction (75 × 16 nm) was in good agreement with the average crystallite size observed using TEM (of 83 × 16 nm). Electron diffraction patterns confirmed coexistence of CaO and Ca(OH)2. The analysis provides an explanation of the enhanced capture/disintegration observed in CaO in the presence of steam.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2012, Royal Society of Chemistry. This is an author produced version of a paper published in Energy and Environmental Science. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Nano-sized crystallites; Phase quantification; Situ x-ray diffraction |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) > Energy Research Institute (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) > Institute for Materials Research (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 23 Jul 2013 09:54 |
Last Modified: | 15 Sep 2014 03:13 |
Published Version: | http://dx.doi.org/10.1039/c2ee21779a |
Status: | Published |
Publisher: | Royal Society of Chemistry |
Identification Number: | 10.1039/c2ee21779a |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:76058 |