Evaluation of the oxidative stability and cold filter plugging point of soybean methyl biodiesel/bovine tallow methyl biodiesel blends

The objective of the present work was to study the oxidative stability (OS) estimated from the induction period (IP) and the cold filter plugging point (CFPP) of blends made with different proportions of soybean methyl biodiesel (BOS) and bovine tallow methyl biodiesel (BSB). BOS is poorly resistant to oxidation because its composition is predominantly unsaturated esters, but it has a satisfactory cold filter plugging point. The BSB is composed of saturated esters and of the lower carbon chain and thus has good oxidation stability values, but has poor CFPP values. Thus, BOS / BSB mixtures in different proportions were made to evaluate the ideal amount of the mixture in which it was possible to obtain IP and CFPP properties in satisfactory values by the legislation. The mixtures started at 10% BSB and 90% BOS and was increased 5% up to the 50% percentage of each biodiesel in each blend. Samples with 45% and 50% BSB had oxidative stability above the minimum required by law, and all blends had the CFPP value within the legal values.