CaO supported on mesoporous silicas as basic catalysts for transesterification reactions

• Published in: Applied catalysis. A, General Vol. 334; no. 1; pp. 35 - 43
• Main Authors: Albuquerque, Mônica C.G., Jiménez-Urbistondo, Inmaculada, Santamaría-González, José, Mérida-Robles, Josefa M., Moreno-Tost, Ramón, Rodríguez-Castellón, Enrique, Jiménez-López, Antonio, Azevedo, Diana C.S., Cavalcante, Célio L., Maireles-Torres, Pedro
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 2008; Elsevier
• Subjects: Biodiesel; CaO; Catalysis; Chemistry; Colloidal state and disperse state; Exact sciences and technology; General and physical chemistry; Heterogeneous catalysis; Porous materials; SBA-15; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Transesterification; CaO; Heterogeneous catalysis; Transesterification; SBA-15; Biodiesel; Support; Porous material; Silica; Catalyst; Mesoporosity
• ISSN: 0926-860X; 1873-3875
• DOI: 10.1016/j.apcata.2007.09.028

CaO supported on mesoporous SBA-15 silicas were prepared and characterized. The transesterification activity of vegetable oils confirms the results obtained with ethyl butyrate and methanol, reaching conversion as high as 95% with sunflower oil (5
h) and 65% (1
h) for castor oil. Moreover, unlike commercial CaO, no lixiviation of the active phase was detected.
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A new group of basic catalysts supported on mesoporous solids has been prepared with the aim of being used as heterogeneous catalysis in biodiesel production. These catalysts based on calcium oxide supported on porous silica (SBA-15, MCM-41 and fumed silica) have been characterized and evaluated in transesterification processes. They were characterized by DRX, XPS, SEM, FT-IR, CO
2-TPD and N
2 adsorption. The catalytic activity was evaluated in the transesterification of ethyl butyrate with methanol, and different reaction parameters were optimized by a factorial design response surface methodology. Thus, a sample containing 14
wt.% of CaO supported on SBA-15 was the most active, and, unlike commercial CaO, no lixiviation of the active phase was detected in the reaction medium. The transesterification activity of vegetable oils confirms the results obtained in the reaction of ethyl butyrate with methanol, reaching conversion as high as 95% with sunflower oil (after 5
h of reaction) and 65% (after 1
h) for castor oil.