Biodiesel is an alternate fuel for diesel consisting of the alkyl monoester of fatty acids derived from vegetable oils. The most usual method to transform oil into biodiesel is transesterification which can be carried out using different catalyst. Jatropha is second generation oil which is non edible and can be use for producing biodiesel. The first part is to expel oil from jatropha seeds. There are different types of expelling methods such as mechanical extraction, solvent extraction and enzymatic extraction. The study was conducted with hand driven mechanical expeller which is most conventional way of extracting oil from seeds with mechanical efficiency of 60-80% for single pass. The study includes various combinations of parameters like seed treatment, sun drying, pre-heating, soaking at different temperatures and different de-hulling compositions. Parameters such as density, kinematic viscosity, free-fatty acid content (FFA), flash point, iodine number, etc, are studied and optimized to get quality jatropha oil with high yield.
The transesterification process consists of heating jatropha oil with methanol at appropriate temperature in the presence of catalyst. Time of reaction, temperature of reaction, amount of methanol & catalyst are some of the important parameters which decide yield and quality of biodiesel. Apart from these, the free fatty acids (FFA) content of jatropha oil plays very important role in deciding yield of biodiesel. Jatropha oil with FFA less than 2% is most preferred for transesterification. Jatropha oil with FFA more than 2% is needed to be neutralized before performing transesterification and it may hamper the final biodiesel yield. This study compares of expelling, neutralization and transesterification processes for producing biodiesel. The parameters are optimized for maximum yield and targeted properties.