Evaluación preliminar del etanol anhidro como solvente en la extracción de aceite de semillas de jatrofa (Jatropha curcas L.)

Abstract

A preliminary evaluation was performed on anhydrous ethanol as a solvent for the extraction of oil from whole Jatropha curcas L. seeds (32.24 % lipids, 16.05 % proteins), supplied from Mato Grosso, Brazil. The methodology of factorial 2k designs was followed, which included a comparison between pressing and n-hexane extraction methods. The regression model corresponding to the comparison between ethanol and n-hexane, varying extraction time, did not have lack of fit and presented an R2 of 99%. The experimental design for the pressing method, varying press rotation speed and temperature, yielded a poorly fitted linear model. The oil composition extracted with ethanol was similar to those obtained by n-hexane and by pressing. The highest yield (36.7%) was obtained using ethanol for 4 hours. The excess of extracted material was attributed to additional solubilization of impurities that could be diminished by limiting the extraction time to 1 hour. The oil extracted with ethanol and by pressing have the same color. It is presumed that the purification steps for both oils should be similar. Further studies using mixtures of ethanol with small proportions of n-hexane are suggested.