Biodiesel Production from Oily Residues Containing High Free Fatty Acids

In this work, fat from industrial food grease trap was used as feedstock for enzymatic synthesis of biodiesel. This fat contains high free fatty acid which can be converted in biodiesel by esterification. The reactions were performed using immobilized lipases from Candida antarctica, Thermomyces lanuginosa and Mucor miehei with factorial design of type 3² to evaluate the best conditions of temperature (30, 40 and 50 °C) and enzyme concentration (5, 7.5 and 10% w w⁻¹). When C. antarctica and T. lanuginosa enzymes were used, high yield was obtained in all studied conditions and none of the variables was statistically significant. For the enzyme from M. miehei significant effect of the temperature was reported, higher yield was obtained with lower temperatures. The lowest yields of biodiesel were obtained using enzyme from M. miehei.

Graphical Abstract