5-36: Biodiesel Synthesis from Babassu Oil Catalysed by Immobilized Lipases on Poly-(Hydroxybutyrate)

Transesterification of vegetable oils to obtain biodiesel consists in replacing the glycerol of triglycerides by a short chain alcohol in the presence of a catalyst that can be basic, acidic or enzymatic. Recent studies show that biodiesel produced by lipases are more attractive, since the glycerol can be easily recovered and the biodiesel purification process is simpler than in the chemical route. Six lipase preparations from Thermomyces lanuginosa (TLL), Candida antarctica (CALB), Bacillus thermocatenulatus (BTL2), porcine pancreas (PPL), Lipex® 100L and Pseudomonas fluorescens (PFL) were immobilized by physical adsorption on granular and powder poly-hydroxybutyrate (PHB) for biodiesel synthesis through transesterification of babassu oil with ethanol. Transesterification reactions were carried out in solvent-free medium at fixed molar ratio babassu oil to ethanol (1:9), employing 10% w/w of biocatalysts in relation to the total weight of reactants under agitation, at 45ºC. PPL and BTL2 led to the lowest conversions of babassu oil into FAEE. The reactions catalyzed by most of the lipases immobilized on granular PHB reached the highest transesterification yields at 24 hours, while most of lipases immobilized on powder PHB reached maximum transesterification yields at 48 hours. Using powder support, the highest reaction yields were 78.5, 75.1 and 70.3% for Lipex® 100L, CALB and TLL derivatives, respectively. The maximum conversion into FAEE (97%) was reached with Lipex® 100L immobilized on powder support at 120 hours of reaction.