Magnesium hydroxide extracted from a magnesium-rich mineral for CO{sub 2} sequestration in a gas-solid system

Magnesium hydroxide extracted from magnesium-bearing minerals is considered a promising agent for binding CO{sub 2} as a carbonate mineral in a gas-solid reaction. An efficient extraction route consisting of hydrothermal treatment on serpentine in HCl followed by NaOH titration for Mg(OH){sub 2} pre...

Full description

Saved in:
Bibliographic Details
Published inEnvironmental science & technology Vol. 42; no. 8
Main Authors Pao-Chung Lin, Cheng-Wei Huang, Ching-Ta Hsiao, Hsisheng Teng
Format Journal Article
LanguageEnglish
Published United States 15.04.2008
Subjects
01 COAL, LIGNITE, AND PEAT
CARBON DIOXIDE
CARBON DIOXIDE FIXATION
CARBON SEQUESTRATION
CARBONATES
CRYSTAL STRUCTURE
DEHYDROXYLATION
DOMAIN STRUCTURE
ENVIRONMENTAL SCIENCES
HYDROTHERMAL SYNTHESIS
MAGNESIUM HYDROXIDES
MAGNESIUM SILICATES
POWDERS
SERPENTINE
SURFACE AREA
X-RAY DIFFRACTION
Online AccessGet full text

Cover

More Information
Summary:Magnesium hydroxide extracted from magnesium-bearing minerals is considered a promising agent for binding CO{sub 2} as a carbonate mineral in a gas-solid reaction. An efficient extraction route consisting of hydrothermal treatment on serpentine in HCl followed by NaOH titration for Mg(OH){sub 2} precipitation was demonstrated. The extracted Mg(OH){sub 2} powder had a mean crystal domain size as small as 12 nm and an apparent surface area of 54 m{sup 2}/g. Under one atmosphere of 10 vol% CO{sub 2}/N{sub 2}, carbonation of the serpentine-derived Mg(OH){sub 2} to 26% of the stoichiometric limit was achieved at 325{sup o}C in 2 h; while carbonation of a commercially available Mg(OH){sub 2}, with a mean crystal domain size of 33 nm and an apparent surface area of 3.5 m{sup 2}/g, reached only 9% of the stoichiometric limit. The amount of CO{sub 2} fixation was found to be inversely proportional to the crystal domain size of the Mg(OH){sub 2} specimens. The experimental data strongly suggested that only a monolayer of carbonates was formed on the crystal domain boundary in the gas-solid reaction, with little penetration of the carbonates into the crystal domain. 24 refs., 6 figs., 2 tabs.
ISSN:0013-936X
1520-5851