Abstract
Energy from biofuel is one of attracting renewable energy sources to substitute fossil fuel. In Ethiopia there is the potential for rubber plantations; however, even though the yield and quality of the rubber seed oil are high, little attention has been given to its use as a source for biodiesel production.
The main aim of the present study was to determine the physical properties of rubber seed, optimize oil extraction from rubber seed, and synthesize biodiesel from rubber seed oil. Seed oil was extracted by solvent extraction method and soil physicochemical properties were determined by Association of Official Analytical Chemists methods. Biodiesel was synthesized by the two-step acid-base catalyze transesterification method with 6:1 molar weight of methanol to oil, at 60 0C reaction temperature for ninety minutes. Biodiesel fatty acid composition was determined by the Gas-chromatography mass spectrometry method. Data were analyzed by design expert software central composite design of response surface methodology. The highest and the lowest oil yield obtained from rubber seed kernel were 61.3 and 3.09 weight %, respectively. Regarding the physicochemical properties of the rubber seed oil, it was 0.91g/cm at 28 C, 6.68mgKOH/g,113.02gI2/100g, 7meq/Kg,215.51mgKOH/g, and 914.65gm/mol for density, acid value, iodine value, peroxide value, saponification value and molecular mass of oil, respectively. The biodiesel yield obtained was 81.55wt%, and the biodiesel was composed of 82.45% unsaturated fatty acid and 15.71% saturated fatty acid. Biodiesel from rubber seed oil is one of the important multi-purpose sources to solve petroleum diesel scarcity and global warming issues coming from the burning of petroleum diesel. In order to use the rubber seed oil for biodiesel production further research is required to enhance the stability of the oil.
Keyword: Biofuel, Fatty acid methyl ester, Rubber seed oil, Vegetable oil.
