OPTIMIZATION OF BIODIESEL PRODUCTION FROM FRYING OIL AND BOVINE TALLOW

Nowadays, discussions about energy-related issues are in evidence. The dynamics of gradual depletion of non-renewable energy reserves, such as oil ones, and global warming have encouraged the search for renewable energy alternatives. The main objective of this work is to evaluate the influence of major operational variables on the transesterification reaction of mixtures of frying oil and bovine tallow, in the presence of methanol, using microwave technology. In an effort to optimize biodiesel production, a statistical design was performed, considering the solvent/feed ratio, the ratio between frying oil and bovine tallow, the amount of KOH, reaction time, and temperature as independent variables. The dependent variables analyzed were biodiesel yield and esters content, obtained by chromatographic analysis. The experiments and the analysis confirmed that a 9:1 solvent/feed molar ratio of, 1.5% catalyst, 35 seconds reaction time, and a mixture containing 70% of frying oil and 30% of bovine tallow provided yields above 89 %. The best conditions to reach 99.43 % of ester content used a 9:1 solvent/feed molar ratio, 0.5 % catalyst, 70%/30% frying oil/bovine tallow, and 35 seconds reaction time.