Adsorption of carbon dioxide on the chemically modified silica adsorbents

Citation
Hk. Song et al., Adsorption of carbon dioxide on the chemically modified silica adsorbents, J NON-CRYST, 242(2-3), 1998, pp. 69-80
Citations number
23
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF NON-CRYSTALLINE SOLIDS
ISSN journal
0022-3093 → ACNP
Volume
242
Issue
2-3
Year of publication
1998
Pages
69 - 80
Database
ISI
SICI code
0022-3093(199812)242:2-3<69:AOCDOT>2.0.ZU;2-F
Abstract
Silica adsorbents were chemically modified to have base sites on their surf acer and the adsorption characteristics of carbon dioxide on them were inve stigated. Base sites were introduced either by impregnation of silica gels with calcium acetate salt or by synthesizing silica xerogels using a sol-ge l method from alcoholic solution of TEOS and calcium acetate salt. The salt in gels was transformed to calcium oxide by calcination at 700 degrees C f or 2 h. The chemically modified adsorbents possess irreversible surfaces, r esulting in chemisorption of carbon dioxide on calcium oxide. However, the adsorbents showed reversible adsorption-desorption cycles of carbon dioxide after one dose of carbon dioxide chemisorption. Interaction between carbon dioxide and base site increased adsorptivity for carbon dioxide at 100 deg rees C and 250 degrees C, Adsorptivity of carbon dioxide represented by Hen ry's constant (mu mol/m(2)/atm) increased by the chemical modification from 0.4 to maximum 1.5 at 100 degrees C and from 0.032 similar to 0.17 to maxi mum 0.7 at 250 degrees C. (C) 1998 Published by Elsevier Science B.V. All r ights reserved.