157Storage Stability of Gas Oils Containing Waste Originated Biocomponent 2014 58 2 Storage Stability of Gas Oils Containing Waste Originated

Nowadays in Europe the demand for diesel fuel is continu-ously growing, while the demand for gasoline decreases slightly. Currently, the biodiesel is the biofuel which is blended into the gas oil with the highest amount in case of Diesel engines, which can be produced from different, even waste-derived triglycer-ides (with transesterification with alcohol). Due to the adverse properties of biodiesel the storage stability of biodiesel/diesel blends has to be examined in detail. In our experimental work we investigated the changes in the qualities of biodiesels produced from vegetable oil which con-tained various waste cooking oil (waste-derived component) share (10, 30, 50%), and its 7 and 10 % blends with gas oil in case of long-term (more than 130 weeks) storage. We found that with increasing the proportion of used cooking oil in the vegetable oil used as raw material for biodiesel, the oxidation reactions took place in a greater degree. Biodiesel made from vegetable oils containing 10 % used cooking oil was the most applicable for blending; in case of using higher proportion it is very necessary to use a further amount of antioxidant additives to minimize the degradation