FUEL PROPERTIES OF BIODIESEL FROM Gmelina arborea AND Trichosanthes cucumerina SEED OILS

Abstract

Growing concerns about environmental problems associated with fossil fuels have engendered so much research into biofuels, such as biodiesel. However, continuous and large-scale production of biodiesel from edible oils could result in serious food security problems if cheap and viable alternatives are not made available. In an attempt to solve this problem, oil was obtained from non-food/underutilized seeds of Gmelina arborea and Trichosanthes cucumerina using Soxhlet apparatus. Physicochemical properties and fatty acids compositions of these oils were determined using standard analytical methods. Biodiesel was processed from these oils via sequential acid (H2SO4) and base (KOH) homogenous catalysis. Fuel properties of biodiesel from both oils were determined using standard methods and the results obtained were compared with standards. Oil yields were found to be 16.10% and 33.37% for G. arborea and T. cucumerina seeds respectively. Physicochemical properties of G. arborea and T. cucumerina oils respectively are: acid value (12.10 and 10.90) mgKOH/g, saponification value (474 and 462) mgKOH/g, iodine value (68.43 and 90.98) mg/100g, viscosity (9.33 and 16.60) mm2/s, flash point (280 and 327) oC. Percentage composition of palmitic, stearic, oleic and linoleic acids in G. arborea oil are; 9.82; 7.51; 32.24 and 43.58 % respectively while those of T. cucumerina are; 6.72; 8.76; 17.59 and 20.45% respectively. G. arborea and T. cucumerina oils gave 86 and 80% biodiesel yields respectively. Fuel properties of biodiesel from G. arborea and T. cucumerina oils respectively are: kinematic viscosity (1.66 and 1.99) mm2/s, pour point (14 and 8) oC, flash point (225 and 228) oC, acid number (0.33 and 0.59) mgKOH/g, energy value (17.23 and 11.17) kJoules/g and sulphated ash (0.00 and 0.01) %, estimated cetane numbers (37 and 31). Biodiesel from these oils significantly met standard quality requirements.