Characterization of Oil and Biodiesel Produced from Thevetia peruviana (Yellow Oleander) Seeds

Abstract

Background: There is increasing emphasis on renewable energy following recurrent economic crises and environmental concerns associated with the use of fossil fuels such as petrodiesel. Research into biodiesel production from oil-bearing renewable biomass sources can provide a more sustainable alternative to petrodiesel. This study evaluated the biodiesel yielding potential of Thevetia peruviana seeds. Methods: Oil was extracted from the seeds using Soxhlet and Cold-solvent extraction methods. Hexane-only (H-only) was used in the Soxhlet while Hexane/Ether (H/E) mixture and H-only were respectively used in the Cold extraction. The oil was processed using Methanol/Ethanol (M/E) mixture and Methanol-only (M-only) respectively to biodiesel via transesterification with sodium hydroxide as catalyst. The oil and biodiesel physicochemical parameters such as density, viscosity at 40oC, Saponification value, Flash Point (FP) and Acid Value (AV) were determined using the American Standard for Testing and Material (ASTM D6751) methods. Results: The oil yields from Soxhlet, H/E and H-only extractions were: 62.3%, 51.9% and 45.8% respectively. The biodiesel yield in the M/E and M-only transesterifications were: 78.4% and 85.20% respectively. The density at 40oC, viscosity, and saponification value of the oil were: 0.868g/cm3, 21.50mm2/s and 120mgKOH/g respectively. The density at 40oC, viscosity, FP and AV of the biodiesel were: 0.760g/cm3, 4.70mm2/s, 130oC and 0.441mgKOH/g respectively. Conclusion: The seeds of Thevetia peruviana are viable sources for biodiesel production, and quality parameters of the biodiesel met the American Standard for Testing and Materials limits. However, further work to explore the optimization of the process and sustainability of the model is recommended.