Extraction and Characterization of the oil, Biodiesel and itʼs blends from Adansonia digitata (Baobab) seed

Abstract

The seeds from Adansonia digitata (Baobab) were subjected to standard chemical analysis to evaluate their properties. The physicochemically properties of Hexane extracted oil and its biodiesel were also characterized. Proximate analysis of the seeds show moisture content (3.5 ± 0.1%), ash content (4.49 ± 0.05%), crude lipids (14.3 ± 0.05%), crude fiber (20.42 ± 0.04%), crude protein (12.97 ± 0.015%), carbohydrate (44.32 ± 0.25%) and total energy (363.024 ± 0.51 K Cal/100g). Mineral compositions was K (90.29ppm), Ca (9.61ppm), P (7.00ppm), Zn (0.268ppm), and Fe (0.227ppm). The yield of oil extract was 21.5%. Results of Physicochemical analysis of oil show free fatty acid content (3.8%), Acid value (1.7 mg KOH/g), Iodine value (54 mg/g), Peroxide value (7.6 mEq/kg), Saponification value (275.05 mg KOH/g), Density at 15C (0.9154 g/cm3), Specific gravity (0.9163%), Kinematic viscosity at 40C (33.69 cSt), Calorific value (43.797 MJ/kg), Cloud point (9C) and Pour point (-3C). After the crude oil extract was transesterified, Biodiesel produced from the baobab (Adansonia digitata) seed oil blended with conventional diesel and ethanol in different ratio as: B20 (biodiesel 20%, diesel 80%), B20E20 (Biodiesel 20%, ethanol 20%, diesel 60%) and B20E30 (Biodiesel 20%, ethanol 30%, diesel 50%). Physicochemical properties of biodiesel, B20, B20E20 and B20E30 revealed the following results; density at 15C (0.8866, 0.8519, 0.8403, 0.8864 g/cm3), kinematic viscosity at 40C (5.8, 3.6, 3.4, 2.7 cSt), calorific value (44.051, 44.354, 44.456, 44.5 MJ kg-1), cloud point (7, 12, 8, 8C) and pour point (-6, -6, -8, -12C), the flash point of biodiesel and B20 was (80, 76.0C) respectively. Gases emission CO2, NO2and NOx of baobab biodiesel and blends was tested and compared with diesel, engine was set at a different speeds 1000, 1500 and 2000 rpm. The blend B20 showed the lowest gases emission.