Evaluation of the performance of natural antioxidants in enhancing biodiesel storage stability

Abstract

Due to the multiple problems of fossil fuels such as air pollution, rising prices, and limited resources, the world has turned to biofuels as an available and less harmful alternative. However, because of their poor stability compared to diesel, biofuels can cause blockage of engine filters due to the oxidation of unsaturated fatty acids. Therefore, antioxidants have received significant attention, both synthetic and natural. Since synthetic antioxidants are toxic to humans and other organisms, attention has been paid to natural antioxidants as non-toxic, available, and biodegradable additives. The main goal of this research paper is to examine the antioxidant activity of two plant by-product extracts, hazelnut skin (H) and red onion peels (R) in inhibiting the autoxidation of biodiesel during accelerated storage at 65 ℃. Their performance was evaluated in terms of acid value and peroxide value under different concentrations of antioxidants. Moreover, the performance of natural extracts (H) and (R) was compared with that of a synthetic antioxidant, Butylated hydroxytoluene (BHT). Results reveal that R at 200 ppm shows promising antioxidant activity.