Derivatisation of glycerol (Gly) with levulinic acid (LA) to produce glycerol trilevulinate (Gt-LE) was studied. The reaction parameters affecting synthesis of Gt-LE were investigated. Catalytic and non-catalytic reactions between Gly and LA were carried out. Effects of reaction time and temperature on non-catalytic reaction were observed. Conversely, for catalysed reaction, reaction parameters studied were type of catalyst, mole ratio, catalyst loading and reaction time. Result analysis indicated that for the catalyst-free reaction, increment of reaction time and temperature will further reduce the acid value of reaction product. On the other hand, for catalytic reaction, p-TsOH accelerated the reaction much faster than montmorillonite, Amberlyst-15 or Amberlyst-46. Result analysis also showed that the best mole ratio and catalyst loading to obtain high composition of Gt-LE without having to go through cumbersome purifying process was 1:6 with 8% catalyst loading. For reaction conducted with mole ratio of 1:6 (Gly:LA), the optimum reaction time and temperature was found to be 8 hr and 140°C, respectively, in which GC analysis showed that product contained about 84.5% of Gt-LE.

Keywords: biodiesel by-product, glycerol, levulinate ester, levulinic acid