Tuesday, May 3, 2011
Biodiesel is an alternative fuel for diesel engines which is commonly prepared from vegetable oils and fats via transesterification with alcohol. The product is called as fatty acid methyl esters or biodiesel. Soybean oil which is a major biodiesel source in North America and East Asia was used as the substrate. In this study, biodiesel production from soybean oil by using supercritical characteristics of methanol was carried out. The operating temperature and pressure were varied from 290°C to 350°C and 220bar to 320bar respectively. The oil to methanol molar ratio and time were varied from 1:30 to 1:60 and 0 to 20min respectively. The reaction was non-catalytic which used supercritical methanol instead of acid or alkali catalyst. The maximum yield of fatty acid methyl ester obtained by this process was 90.5wt%. This maximum yield was achieved at a temperature of 340°C, pressure of 260bar, reaction time of 5min and molar ratio of oil to methanol 1:50.