Evaluation of the use of degummed soybean oil and supercritical ethanol for non-catalytic biodiesel production

In this work the production of fatty acid ethyl esters (FAEE) from degummed soybean oil in supercritical ethanol was investigated. The process parameters were defined as reaction temperature (250-340 degrees C), residence time (11-50 min) and ethanol:oil molar ratio (9:1-51:1). All experiments were performed in a continuous reactor at 20 MPa. The effect of each parameter and their interactions on the yield of fatty acid ethylic esters was studied using design of experiments (DOE). Results showed that all three single parameters were significant on the yield of FAEE and that reactions of degummed soybean oil with ethanol led to esters yields up to 65%, in these experimental conditions. These values are inferior when compared to the ones obtained with refined soybean oil probably due to the presence of several impurities in degummed soy bean oil such as pigments, antioxidants and phospholipids. Despite of this lower yield, the use of degummed soybean oil can still be a good alternative since this is a non-edible lower cost raw material. (C) 2015 Elsevier B.V. All rights reserved.