Larnite powders and larnite/silica aerogel composites as effective agents for CO2 sequestration by carbonation

JOURNAL OF HAZARDOUS MATERIALS

卷:168

Article

Santos, A.¹  Ajbary, M.²  Morales-Florez, V.²  Kherbeche, A.³  Pinero, M.⁴  Esquivias, L.⁵ 

[1] Univ Cadiz, Dept Ciencias Tierra, Cadiz 11510, Spain

[2] Univ Cadiz, Dept Fis Mat Condensada, Cadiz 11510, Spain

[3] Univ Sidi Mohamed Ben Abdellah, Ecole Super Technol, Fes, Morocco

[4] Univ Cadiz, Dept Fis Aplicada, Cadiz 11510, Spain

[5] Univ Seville, CSIC, Fac Fis, Dept Fis Mat Condensada,Inst Ciencias Mat Sevilla, Seville 41012, Spain

关键词: Larnite;    Larnite-silica aerogel composites;    CO2;    Carbonation;    Mineral sequestration;   

DOI  :  10.1016/j.jhazmat.2009.03.026

来源: Elsevier

【 摘 要 】

This paper presents the results of the carbonation reaction of two sample types: larnite (Ca2SiO4) powders and larnite/silica aerogel composites, the larnite acting as an active phase in a process of direct mineral carbonation. First, larnite powders were synthesized by the reaction of colloidal silica and calcium nitrate in the presence of ethylene glycol. Then, to synthesize the composites, the surface of the larnite powders was chemically modified with 3-aminopropyltriethoxysilane (APTES), and later this mixture was added to a silica sol previously prepared from tetraethylorthosilicate (TEOS). The resulting humid gel was dried in an autoclave under supercritical conditions for the ethanol. The textures and chemical compositions of the powders and composites were characterized. The carbonation reaction of both types of samples was evaluated by means of X-ray diffraction and thermogravimetric analysis. Both techniques confirm the high efficiency of the reaction at room temperature and atmospheric pressure. A complete transformation of the silicate into carbonate resulted after submitting the samples to a flow of pure CO2 for 15 min. This indicates that for this reaction time, 1 t of larnite could eliminate about 550 kg Of CO2. The grain size, porosity, and specific surface area are the factors controlling the reaction. (C) 2009 Elsevier B.V. All rights reserved.

【 授权许可】

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