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Title: Reaction mechanisms for enhancing mineral sequestration of CO{sub 2}

Journal Article · · Environmental Science and Technology
DOI:https://doi.org/10.1021/es8033507· OSTI ID:21233765
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  1. Arizona State University, Tempe, AR (United States). School of Materials

Storage of CO{sub 2} through mineral sequestration using olivine has been shown to produce environmentally benign carbonates. However, due to the formation of a rate-limiting reaction product layer, the rate of reaction is insufficient for large-scale applications. We report the results of altering the reactant solution composition and the resultant reaction mechanism to enhance the reaction rate. The products were analyzed for total carbon content with thermal decomposition analysis, product phase compositions with Debye-Scherrer X-ray powder diffraction (XRD), surface morphology with scanning electron microscopy (SEM), and composition with energy dispersive X-ray spectroscopy (EDXS). Carbon analysis showed that an increase in bicarbonate ion activity increased the olivine to carbonate conversion rate. The fastest conversion rate, 63% conversion in one hour, occurred in a solution of 5.5 M KHCO{sub 3}. Additionally, SEM confirmed that when the bicarbonate ion activity was increased, magnesium carbonate product particles significantly increased in both number density and size and the rate passivating-reaction layer exfoliation was augmented. 30 refs., 5 figs., 1 tab.

OSTI ID:
21233765
Journal Information:
Environmental Science and Technology, Vol. 43, Issue 16; ISSN 0013-936X
Country of Publication:
United States
Language:
English