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Lipase-catalysed synthesis of ester oils from biodiesel by-products |
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| Authors: | Professor Dr Marco Schlepütz Andreas Buthe Rudolf Brenneis Marion B. Ansorge-Schumacher |
| Affiliation: | 1. Department of Biotechnology, RWTH Aachen University, D-52056, Aachen, Germanym.ansorge@chem.tu-berlin.de;3. Department of Biotechnology, RWTH Aachen University, D-52056, Aachen, Germany;4. Federal Institute for Materials Research and Testing, D-12489, Berlin, Germany;5. Technical University of Berlin, Institute of Chemistry, Enzyme Technology (TC4), D-10623, Berlin, Germany |
| Abstract: | Ester oils obtained from natural long-chain fatty acids and alcohols are versatile substitutes for many petroleum-based products. Their efficient synthesis with the solvent-free esterification of free fatty acids (FFA) from by-products of biodiesel fabrication and 2-ethyl-1-hexanol with immobilised lipase from Thermomyces lanuginosa was investigated. The immobilisation of the biocatalyst in static emulsion yielded a specific esterification activity that was higher by a factor of 4.9–9.4 than the activity of the native enzyme. Favourable properties of the silicone-based immobilisation matrix in terms of stability and immobilisation yield were observed. In biodiesel by-products, the immobilised lipase catalysed the esterification of FFA as well as the transesterification of residual fatty acid methyl esters (FAME) to the desired ester oils. A conversion of 90% FFA and 35% FAME gave a total yield of 60%. The inactivation coefficients during repeated use in a stirred-tank reactor with intermittent pressure reduction were exceptionally low. |
| Keywords: | Ester oil biodiesel lipase esterification static emulsion |