EFFECTS OF THE ADDITION OF [2HEA][HX] ON BIODIESEL SYNTHESIS USING METHANOL AND METHANOL/ETHANOL MIXTURE

Abstract

Currently, the use of ionic liquids (ILs), such as catalysts and co-solvents, in the production of biodiesel commonly demands extreme operating conditions (especially temperature and / or time). Besides the environmental benefits, these compounds have versatile physical and chemical properties. Some of these compounds also possess amphiphilic features that allow them to act as surfactants and, in this case, when employed as additives in transesterification reactions, they can overcome mass transfer limitations and, consequently, the reaction rate. This work aims at studying the effects of protic ionic liquid (PIL) 2-hydroxyethylammonium hexanoate [2HEA][Hx] in the alkaline transesterification of soybean oil using methanol and a methanol/ethanol mixture. The reaction conditions were alcohol/oil molar ratio of 6:1, 1.5% (%wt/wt) KOH as the catalyst, 2% (%wt/wt) PIL as the additive, 60 °C, and 30 min reaction time. The highest mass yield was 92.72% for both pure methanol and methanol/ethanol mixture (molar ratios 5:1), since the mean was not statistically different for those two ratios.