Improvement of cold flow properties and stability of biodiesel fuel produced from fatty waste

Abstract

The use of alternative fuels made from renewable natural resources has considerably increased during the last years, as well as the importance of biodiesel. Nevertheless, insufficient oxidative stability and unsatisfactory cold flow properties of monoalkyl esters of fatty acids limit their successful application. As both of these parameters are largely related to unsaturation degree of fatty acids, we investigated biodtesels obtained from very different fats ~ strongly unsaturated Unseed oil, animal fat mostly based on saturated fatty acids, as well as rapeseed oil. The influence of BHA and BHT additives on oxidative stability of biodiesels was evaluated by Rancimat induction period. The impact of different commercially available antifreezes, as well as acetals and ketals (synthesized from crude glycerol obtained as by-product of biodiesel production) on cold filter plugging point, pour and cloud points of methyl esters of fatty acids was studied.