Process optimization for biodiesel production from Nigella sativa oil

Nigella sativa is a plant known for its uses as herbal and medical purposes. Seeds of Nigella sativa have a high level of oil content. In this study, biodiesel is produced from Nigella sativa oil by using the transesterification method. An acid catalyst is used since Nigella sativa oil has 5.36% free fatty acid content. Parameters such as catalyst ratio, methanol ratio and temperature are optimized for 3 hours of reaction period. Optimal conversion efficiency is obtained to be 82.74% at 40 wt.% methanol/oil ratio, 4 wt.% catalyst concentration, and 70 degrees C reaction temperature. Methyl esters in Nigella sativa biodiesel are determined by Gas Chromatography-Frame Ionized Detector (GC-FID). Some basic characteristics of the produced methyl ester are determined and it is concluded that it possesses some requirements for biodiesel standards.