Abstract:
The aim of this research is to synthesize chemical additives from isopropyl ester of sunflower oil in order to improve cold flow properties of palm biodiesel. The chemical additives which were synthesized via transesterification, epoxidation and alkoxylation are alkoxy isopropyl esters and they were characterized by 1H-NMR technique. These synthetic additives were added into palm biodiesel at level of 50,000 100,000, 150,000 and 200,000 ppm to compare their effect to cold flow properties. The results showed that these synthetic additives can reduce cloud point (CP) and pour point (PP) of palm biodiesel. The length of alkoxy chain is also affected the cold flow properties of palm biodiesel. Long alkoxy chain makes the distance between molecules increased resulting in hindering molecular packaging, which unfavors crystallization when temperature drops. The best synthetic additive is given to 1-Octoxy isopropyl ester, which it decreases cloud point and pour point of palm biodiesel from 19.4 ํC to 13.5 ํC and 11.2 ํC to 7.0 ํC, respectively, when adding in the amount of 200,000 ppm.