The macaúba (Acrocomia aculeata) is a native fruit of the Brazilian cerrado with potential to produce up to 6.5 ton of oil/ha. The macaúba pulp oil presents, few weeks after fruit harvest, high content of free fatty acids (FFA) and is usually used to soap production. In this work, two alternatives routes were compared for producing biodiesel from macaúba pulp oil with 35% of FFA. The selected routes, hydroesterification and biocatalyst, are able to use less expensive feedstocks that cannot be converted to biodiesel by conventional methods. The hydrolysis of the oil was carried out at 300^oC, followed by acid-catalyzed methanolysis performed at 190^oC with niobic acid (NB-340 CBMM) as catalyst at concentration of 10 wt% relative to FFA. A commercial, (Novozym 435) immobilized lipase, at concentration of 10 wt% relative to oil, was employed as a catalyst for converting the macaúba oil to biodiesel, via alcoholysis. The conversion efficiency to methyl esters were analyzed by colorimetric method. The hydroesterification processes reached 78% and 22% of conversion in a small reaction time (60 minutes) with and without catalyst, respectively. The immobilized lipase has produced a superior conversion (85%) after 72 hours. Although the esterification time using lipase is very high, bioconversion appears as a cleaner technology to biodiesel production. Furthermore, the biodiesel presented lower viscosity and better quality due to very low temperature of enzymatic reaction (35^oC). The economic feasibility of enzymatic esterification can be enhanced by recycling the immobilized enzyme.

Key-words: macaúba, biodiesel, lipase, hydroesterification.