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Ferrao-Gonzales A.D.,Nucleo de Biotecnologia NuBiotec | Veras I.C.,Nucleo de Biotecnologia NuBiotec | Silva F.A.L.,Nucleo de Biotecnologia NuBiotec | Alvarez H.M.,Nucleo de Biotecnologia NuBiotec | And 2 more authors.
Fuel Processing Technology | Year: 2011

Biodiesel is a biofuel expected to become a substitute for petroleum diesel. One of the most promising technologies for production of biodiesel is enzymatic catalysis. However, low catalytic performance of most of the enzymes employed makes such processes expensive and time-consuming. This work describes a kinetic study of the enzymatic production of biodiesel at different temperatures using either methanolysis or ethanolysis, using immobilized lipase from Candida antarctica (Novozym 435) as catalyst. Reactions kinetics were followed by GC, and data were used to perform thermodynamic analysis of the transition state using Arrhenius equation. We found that methanolysis is faster than ethanolysis at temperatures above 13 °C. Thermodynamic analysis of the kinetics of reactions showed that methanol is favored as acyl acceptor due to the positive activation entropy change of reaction. These data may be useful in the development of new enzymes and new processes for enzymatic production of biodiesel. © 2010 Elsevier B.V. Source

Veras I.C.,Federal University of Bahia | Silva F.A.L.,Nucleo de Biotecnologia NuBiotec | Ferrao-Gonzales A.D.,Nucleo de Biotecnologia NuBiotec | Moreau V.H.,Nucleo de Biotecnologia NuBiotec | Moreau V.H.,Federal University of Bahia
Bioresource Technology | Year: 2011

This work aims to demonstrate the enzymatic production of fatty acid ethyl ester biodiesel from highly acidic feedstock in a single-step reaction, without co-solvents and avoiding the inhibition of the enzyme by ethanol and glycerol. Additionally, an empirical equation is proposed to predict the kinetics of the production reaction as a function of the used feedstock and catalyst concentration. Biodiesel production from highly acidic feedstock perform via simultaneous esterification of free fatty acids and transesterification of triacylglycerols. Enzymatic catalysis is one of the most promising alternative technologies for the biodiesel production. Increasing of the enzymatic bioactivity is crucial for the success of such process in industrial scale. Currently, stepwise addition of the alcohol or the use of co-solvents have been proposed to avoid enzyme inhibition, such strategies add downstream processes to the production. These results can be applied to the development economical-viable enzymatic production of biodiesel in industrial scale. © 2011 Elsevier Ltd. Source

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