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Production of fatty acid ethyl esters from waste cooking oil using Novozym 435 in a solvent-free system Débora M Kochepka, Laís Pastre Dill, Gustavo H. Couto, Nadia Krieger, and Luiz Pereira Ramos Energy Fuels, Just Accepted Manuscript • DOI: 10.1021/acs.energyfuels.5b02116 • Publication Date (Web): 18 Nov 2015 Downloaded from http://pubs.acs.org on December 2, 2015
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Production of fatty acid ethyl esters from waste cooking oil using Novozym®
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435 in a solvent-free system
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Débora M. Kochepka1,3, Laís P. Dill1, Gustavo H. Couto1,2, Nadia Krieger1, Luiz P.
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Ramos1,3*
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University of Paraná, UFPR, P.O. Box 1908, Curitiba, Paraná, 81531-980, Brazil.
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Research Center in Applied Chemistry, CEPESQ - Department of Chemistry, Federal
Department of Chemistry and Biology, Federal University of Technology – Paraná,
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UTFPR, Curitiba, Paraná, 81280-340, Brazil.
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INCT in Energy and Environment, INCT E&A, Curitiba, Paraná, 81531-980, Brazil.
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ABSTRACT
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Fatty acid ethyl esters (FAEE) were produced from waste cooking oil (WCO) using the
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immobilized Novozym® 435 (Novozymes) lipase in a solvent-free system. WCO contained
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high molar mass degradation compounds that did not affect the lipase activity but remained
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as a minor component of the resulting FAEEs. The enzyme-catalyzed FAEE production
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was investigated using a central composite design. The best experimental conditions were
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obtained with an enzyme loading of 5 wt% and an ethanol:oil molar ratio of 6:1. Under
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these conditions and at the optimal enzyme temperature of 40 °C, FAEE mixtures with a
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total ester content of 77.2 and 89.5 wt% were produced after 10 and 24 h, respectively.
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Treatment of the spent biocatalyst with tert-butanol could restore the transesterification
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activity of the biocatalyst to its original value.
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KEYWORDS: waste cooking oil; ethanolysis; immobilized lipase; Novozym 435;
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solvent-free system.
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1. INTRODUCTION Biomass-derived biofuels such as ethanol and biodiesel currently contribute with
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nearly 10% of the world primary energy production 1. The main drivers for the
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development of this market are the economic dependence on petrochemicals, the
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conflicting geopolitical issues related to such dependence, and the environmental impact
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that is caused primarily by the extensive and often inefficient use of fossil fuels.
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Biodiesel is composed of long chain fatty esters that can be obtained by the
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esterification of fatty acids and by the transesterification of vegetable oils and animal fats
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with a short chain monohydroxylated alcohol, ideally in the presence of a homogeneous,
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heterogeneous or enzymatic catalyst 2, 3. Traditionally, biodiesel is produced by
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homogeneous basic catalysis and this technology requires the use of raw materials with
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low water content (