Glycerol-intercalated Mg-Al hydrotalcite as a potential solid base catalyst for transesterification
Xi, Yuanzhou (University of Virginia. Department of Chemical Engineering)
Davis, Robert J. (University of Virginia. Department of Chemical Engineering)

Data:	2010
Resum:	Glycerol is a byproduct of biodiesel synthesis by transesterification of triglycerides with short- chain alcohols in the presence of solid base catalysts. Because hydrotalcite is a potentially useful basic catalyst for the transesterification reaction, the interaction of glycerol with hydrotalcite is the focus of this work. Glycerol was intercalated into Mg-Al hydrotalcite with a Mg/Al molar ratio of 4 under elevated temperatures of 443 503 K in the absence and presence of NaOH. The resulting materials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and N adsorption. The amount of glycerol incorporated into hydrotalcite increased with increasing temperature of intercalation. However, the brucite-like sheets of hydrotalcite partially decomposed during the intercalation process at the highest temperature. The presence of NaOH stabilized the hydrotalcite layers against decomposition under high temperature (503 K). The intercalated materials exposed large surface areas ranging from 142 to 663 m g, depending on the preparation conditions. The glycerol-intercalated hydrotalcites were less catalytically active than hydrotalcite with OH counterions for the transesterification of tributyrin with methanol. The lower reactivity of glycerol-intercalated hydrotalcite was probably the result of a strong interaction between the intercalated glycerolate (HOCH-CHOH- CHO) and the partially decomposed brucite-like sheets.
Drets:	Tots els drets reservats.
Llengua:	Anglès
Document:	Article ; recerca ; Versió publicada
Matèria:	Biodiesel ; Catalyst ; DTG ; FTIR ; Glycerol ; Hydrotalcite ; TGA ; Transesterification ; Tributyrin ; XRD
Publicat a:	Clays and Clay Minerals, Vol. 58, Núm. 4 (2010) , p. 475-485, ISSN 1552-8367

DOI: 10.1346/CCMN.2010.0580403

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