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Lipase‐catalyzed ethanolysis of soybean oil in a solvent‐free system using central composite design and response surface methodology
Author(s) -
Rodrigues Rafael Costa,
Volpato Giandra,
Ayub Marco Antônio Záchia,
Wada Keiko
Publication year - 2008
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.1879
Subject(s) - central composite design , response surface methodology , yield (engineering) , lipase , biodiesel , soybean oil , substrate (aquarium) , chemistry , catalysis , solvent , biofuel , composite number , chemical engineering , organic chemistry , chromatography , materials science , enzyme , food science , microbiology and biotechnology , composite material , oceanography , geology , biology , engineering
BACKGROUND: In this work we describe the synthesis of ethyl esters, commonly known as biodiesel, using refined soybean oil and ethanol in a solvent‐free system catalyzed by lipase from Thermomyces lanuginosus . Central composite design and response surface methodology (RSM) were employed to optimize the biodiesel synthesis parameters, which were: reaction time, temperature, substrate molar ratio, enzyme content, and added water, measured as percentage of yield conversion. RESULTS: The optimal conditions obtained were: temperature, 31.5 °C; reaction time, 7 h; substrate molar ratio, 7.5:1 ethanol:soybean oil; enzyme content, 15% (g enzyme g −1 oil); added water, 4% (g water g −1 oil). The experimental yield conversion obtained under these conditions was 96%, which is very close to the maximum predicted value of 94.4%. The reaction time‐course at the optimal values indicated that 5 h was necessary to obtain high yield conversions. CONCLUSION: A high yield conversion was obtained under the optimized conditions, with relative low enzyme content and short time. Comparison of predicted and experimental values showed good correspondence, implying that the empirical model derived from RSM can be used to adequately describe the relationship between the reaction parameters and the response (yield conversion) in lipase‐catalyzed biodiesel synthesis. Copyright © 2008 Society of Chemical Industry