Catalytic properties of spinel-type mixed oxides in transesterification of vegetable oils

• Published in: Journal of molecular catalysis. A, Chemical Vol. 379; pp. 234 - 242
• Main Authors: Sankaranarayanan, T.M., Shanthi, R. Vijaya, Thirunavukkarasu, K., Pandurangan, A., Sivasanker, S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.11.2013; Elsevier
• Subjects: Biodiesel; Catalysis; Chemistry; Exact sciences and technology; General and physical chemistry; Spinels; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Transesterification; Vegetable oils; ZnFe2O4; Vegetable oils; ZnFe2O4; Transesterification; Spinels; Biodiesel; Heterogeneous catalysis; Catalytic reaction; Spinel; Oxides; ZnFe; Vegetable oil; O
• ISSN: 1381-1169; 1873-314X
• DOI: 10.1016/j.molcata.2013.08.027

•Spinel-type mixed oxides are active in transesterification of vegetable oil.•“Zn” containing spinels are more active compared to other spinel-type compounds.•ZnFe2O4 is active in transesterification for non-edible oils also.•ZnFe2O4 is reusable and suitable for use in fixed-bed reactor. Crystalline mixed oxides of AB2O4 composition, where A=Co, Ni, Cu and Zn and B=Al, Fe and Co, were prepared by co-precipitation of hydroxides and calcination at 873K. The catalytic activity of these materials in the transesterification of sunflower oil with methanol to produce fatty acid mono esters (FAME; biodiesel) was investigated. The transesterification activity was found to depend on element A, the order of activity being: Zn>Cu>Ni>Co. The Zn containing spinels were more active than the others and their activity was found to go through a maximum with Sanderson's intermediate electronegativity. Detailed investigations carried out on ZnFe2O4 revealed it to be a suitable solid catalyst for the transesterification of used cooking oil and Jatropha oil. The catalyst was reusable many times. The performance of this spinel was also investigated in a bench-scale (30g catalyst loading) fixed-bed reactor.