Esterification of Oleic Acid for Biodiesel Production Catalyzed by Sncl2: a Kinetic Investigation
Energies 2008, 1, 79-92; DOI: 10.3390/en1020079 energies ISSN 1424-8220 www.mdpi.org/energies Article
Esterification of Oleic Acid for Biodiesel Production Catalyzed by SnCl2: A Kinetic Investigation
Abiney L. Cardoso, Soraia Cristina Gonzaga Neves and Marcio J. da Silva *
Departament of Chemistry, Federal University of Viçosa, Viçosa, Minas Gerais, Brazil, 36570-000.
* Author to whom correspondence should be addressed; E-Mail:silvamj2003@ufv.br
Received: 5 August 2008; in revised form: 16 September 2008 / Accepted: 17 September 2008 /
Published: 24 September 2008
Abstract: The production of biodiesel from low-cost raw materials which generally contain high amounts of free fatty acids (FFAs) is a valuable alternative that would make their production costs more competitive than petroleum-derived fuel. Currently, the production of biodiesel from this kind of raw materials comprises a two-stage process, which requires an initial acid-catalyzed esterification of the FFA, followed by a basecatalyzed transesterification of the triglycerides. Commonly, the acid H2SO4 is the catalyst on the first step of this process. It must be said, however, that major drawbacks such as substantial reactor corrosion and the great generation of wastes, including the salts formed due to neutralization of the mineral acid, are negative and virtually unsurmountable aspects of this protocol. In this paper, tin(II) chloride dihydrate (SnCl2·2H2O), an inexpensive
Lewis acid, was evaluated as catalyst on the ethanolysis of oleic acid, which is the major component of several fat and vegetable oils feedstocks. Tin chloride efficiently promoted the conversion of oleic acid into ethyl oleate in ethanol solution and in soybean oil samples, under mild reaction conditions. The SnCl2 catalyst was shown to be as active as the mineral acid H2SO4. Its use has relevant advantages in comparison to mineral acids catalysts, such as less corrosion of the reactors and as well as
Esterification of Oleic Acid for Biodiesel Production Catalyzed by SnCl2: A Kinetic Investigation
Abiney L. Cardoso, Soraia Cristina Gonzaga Neves and Marcio J. da Silva *
Departament of Chemistry, Federal University of Viçosa, Viçosa, Minas Gerais, Brazil, 36570-000.
* Author to whom correspondence should be addressed; E-Mail:silvamj2003@ufv.br
Received: 5 August 2008; in revised form: 16 September 2008 / Accepted: 17 September 2008 /
Published: 24 September 2008
Abstract: The production of biodiesel from low-cost raw materials which generally contain high amounts of free fatty acids (FFAs) is a valuable alternative that would make their production costs more competitive than petroleum-derived fuel. Currently, the production of biodiesel from this kind of raw materials comprises a two-stage process, which requires an initial acid-catalyzed esterification of the FFA, followed by a basecatalyzed transesterification of the triglycerides. Commonly, the acid H2SO4 is the catalyst on the first step of this process. It must be said, however, that major drawbacks such as substantial reactor corrosion and the great generation of wastes, including the salts formed due to neutralization of the mineral acid, are negative and virtually unsurmountable aspects of this protocol. In this paper, tin(II) chloride dihydrate (SnCl2·2H2O), an inexpensive
Lewis acid, was evaluated as catalyst on the ethanolysis of oleic acid, which is the major component of several fat and vegetable oils feedstocks. Tin chloride efficiently promoted the conversion of oleic acid into ethyl oleate in ethanol solution and in soybean oil samples, under mild reaction conditions. The SnCl2 catalyst was shown to be as active as the mineral acid H2SO4. Its use has relevant advantages in comparison to mineral acids catalysts, such as less corrosion of the reactors and as well as
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