New trends in biodiesel production: Chemical interesterification of sunflower oil with methyl acetate

In this study, the chemical interesterification of oil with methyl acetate using potassium hydroxide, methoxide and polyethylene glycolate as catalysts was investigated. The reactions were performed at 50 °C using the range methyl acetate 12 mol mol−1 of refined sunflower oil to a value of 100 mol mol−1 and the range of potassium methanolate to oil was 100–500 mmol mol−1. The effect of methanol and water on the catalyst and reagents was to reduce the yield of triacetin, forming diacetin, monoacetin and glycerol instead. A compromise between the product yield, reaction kinetics and methyl acetate recovery was achieved with the conditions methyl acetate to oil 50 mol mol−1 and catalyst to oil 100 mmol mol−1 when potassium methoxide was used as a catalyst and the reagents were dehydrated. Under these conditions, equilibrium was reached within the first 15 min of the reaction. The mass fractions of fatty acid methyl esters (FAME) and triacetin in the product were 76.7% and 17.2%, respectively, with a mass fraction of 4.7% for the intermediate diacetinmonoglyceride. Diacetin, monoacetin and glycerol were also found at a mass fraction of 1.2%.