Produção de ésteres metílicos a partir de gordura residual de frango

Abstract

The decrease in fossil fuel reserves and their adverse environmental effects motivate the production of biofuels such as biodiesel. Animal fats residues, generated by agro-processing industries in large quantities, are a convenient raw material for conversion to alkyl esters (biodiesel). This research aimed to produce methyl esters from residual chicken fat by chemical (NaOH) and enzymatic catalysis (NS-40116 - liquid formulation of the modified Thermomyces lanuginosus lipase). The variables "fat/methanol molar ratio" and "catalyst percentage" for the chemical route and "fat/methanol molar ratio", "water percentage" and "temperature" for the enzymatic route were evaluated. For the chemical catalysis the fat was previously treated to decrease the acidity and promoted the highest conversion in ester (73%) with 1% catalyst and 1/5 fat/methanol molar ratio. The enzymatic catalysis (0.3 wt% enzyme) presented the most efficient condition at 35ºC, 2 wt% water and 1/4 fat/methanol molar ratio, yielding 56% in ester. For this condition, a purification of the obtained esters was carried out which significantly increased the yield to 99.99%. Therefore, the residual chicken fat is a suitable raw material for biodiesel production.