OXIDATIVE AND STORAGE STABILITY OF BIODIESEL MADE FROM RAPESEED OIL

摘要

As an environmentally compatible and cost-effective alternative to conventional diesel, biodiesel hasmarkedly increased its share in the fuel market. Inability to predict its deterioration rate and shelf life from qualitycharacteristics of EN14214 standard can lead to performance problems in all types of diesel fuel equipment. Theobjectives of this study are to determine the oxidative stability of biodiesel samples by the Rancimat method and findsome relationship between oxidative stability and shelf life obtained by monitoring acid value and viscositycharacteristics during storage under conditions that are similar to those encountered in use (at 40 °C in low light). Theoxidative stability of biodiesel made from rapeseed oil was improved by adding the antioxidant Butylatedhydroxytoluene. The results show that the shelf life determination from two different parameters gives practically thesame results. In our experiments the oxidative stability changes within 5,89 - 12,37 h, but the shelf life (SL) within1250 - 8200 h. The shelf life is related to the Rancimat induction period by the relationship lg(SL) = 2,54lg(Rancimat induction period) + 1,125 (R = 0,9992), which can be used for predicting the shelf life.