A seed of Albizzia julibrissin wild plant as an efficient source for biodiesel production

Abstract

The Albizzia julibrissin seed oil was studied for the first time as a promising unconventional raw material for the preparation of biodiesel fuel. We aim to optimize different oil extraction reaction parameters, alkali-catalyzed transesterification process for maximal biodiesel production and finally evaluated its compatibility with mineral diesel. In the present work, various solvents, as well as various catalysts were tested before potassium hydroxide was chosen for further study. The optimization factors in transesterification included the molar ratio of oil to methanol, stirring rate, reaction duration, catalyst concentration (potassium hydroxide) and biodiesel production temperature. The optimal conditions comprised the ratio of methanol to oil was 6:1 M, reaction time was 60 min, the amount of catalyst was 0.30 g, and the temperature was 65 °C. Under these conditions, the yield of Albizzia julibrissin methyl ester obtained was 98%. The Soxhlet extraction process provides the maximum Albizzia julibrissin oil content, in the range of 19–24%, followed by 9.9% of mechanical extraction. Gas chromatography provides a foundation for classifying the fatty acid composition of oils. The characterization of biodiesel products was carried out by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy (1H and 13C), and gas chromatography-mass spectrometry. The fuel characteristics of Albizzia julibrissin were determined according to the American Standard for Testing Material and European Norm test methods which confirmed it as a suitable alternative to petroleum diesel. In conclusion, Albizzia julibrissin seed oil can be considered as a new raw material for biodiesel production.