Production and characterization of biodiesel from oil of fish waste by enzymatic catalysis

The objective of this paper was to optimize, by composite central design coupled to response surface methodology, the enzymatic biodiesel production from oil coming from fish waste, and to characterize the obtained product. The lipase from Thermomyces lanuginosus immobilized on octadecyl metacrylate beads was used as biocatalyst. Optimal conditions were temperature of 35 degrees C, 10% w/w of biocatalyst content and 216 rpm of agitation rate. Under optimal conditions, an experimental biodiesel yield of 75.3% was obtained after 24 h of reaction time. The biodiesel presented an acid value (0.9 +/- 0.28 mg KOH/g) that was higher than the established limits, while other parameters like density (0.89 +/- 0.01 g/mL), viscosity (5.3 +/- 0.004 mm(2)/s), calorific value (38.1 +/- 0.21 MJ/kg) and cloud point (10.5 +/- 0.47 degrees C), complied with the recommendations of the ASTM D6751 standard. (C) 2020 Elsevier Ltd. All rights reserved.