Thermo-analytical characterizations of biodiesel produced from edible and non-edible oils

The work aims at evaluating the thermo-analytical aspects and rheological behavior of methyl esters derived from transesterification of both edible (Mustard and Flaxseed oils) and non-edible (Mahua and Karanja oils) crude oils. Edible oils were transesterified using one stage transesterification reaction however due to the high content of free fatty acids (> 3%) in non-edible oils, two-stage transesterification was employed. The non-isothermal DSC (differential scanning calorimetry) studies at five different heating rates βi, i.e., 5, 7.5, 10, 15 and 20 °C/min was employed for oxidative stability evaluation of samples. Due to more saturated components, the oxidative stability of non-edible oil esters was found to be superior to edible oil esters. The presence of more saturated components in non-edible oils results in inferior cold flow property as compared to edible oil esters. The viscosity study at 30 °C revealed that the viscosity of methyl esters is less than that of raw vegetable oils.