The process of hidroesterification (hydrolysis followed by esterification) is constituted as an alternative to the conventional process for producing biodiesel, because it allows the use of raw materials of any content of fatty acids and moisture. Biodiesel is derived from the esterification of Andiroba oil with high content of fatty acids being used niobium oxide powder (HY-340) from Brazilian Company of Metallurgy and Mining - CBMM – as a catalyst. For the execution of experiments was used an autoclave reactor (batch). The hydrolysis reaction was conducted at 300oC, 1200 psi and molar ratio water/oil equal 20. In the esterification reactions were observed the effects of molar ratio methanol/fatty acid (1,2; 2,1 an 3,0), temperature (150, 175 and 200oC) and the concentration of catalyst (0, 10 and 20%) on conversion and initial rate of reaction. The data were conducted according to experimental design (factorial with 23 and adding 3 plants points) analyzed by the program Statistica. The conversion of esterification reaction was monitored from measurements of titrimetric acidity of aliquots removed at times of 5, 10, 15, 20, 25, 30, 45 and 60 minutes. In the experiments of esterification the highest conversion obtained was 96.1% with temperature of 200 o C, 20% m / m of catalyst and molar ratio methanol / acid equal to 3.0. Eliminating the catalyst and recital the same levels for the other two analyzed variables (temperature and molar ratio), was obtained a conversion of 95.3%, however was observed a conversion rate child, taking-if an increase of 35 minutes in the time of compared with the reaction catalyzed reaction.
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