Synthesis and Characterization of Biodiesel from Non-Edible Seed Oils Extracted from Cameroon Bioresources

This work aimed at valorizing non-edible seed oils from some plants found in Cameroon videlicet Acacia hockii (AH), Garcinia livingstonei (GL) and Moringa oleifera (MO), through production of biodiesel. Two extraction methods used were; the Soxhlet extraction and surfactant assisted extraction with sodium dodecyl sulphate (SDS) as surfactant. The extracted oils were characterized using physicochemical parameters. The characterized oils were used to synthesize biodiesels via acid and base catalyzed transesterification reactions. The purification of the biodiesels was done using chromatographic columns. The biodiesels obtained were also characterized using physicochemical analysis in a manner similar to the oils with additional parameters like cold f low properties, f lammability, ignition qualities and cetane number determinations. Qualitative analysis was realized using the Fourier Transformed Infrared Spectrophotometer (FT-IR). The Soxhlet extraction method gave higher yields for all the plants with MO being the highest, compared to the surfactant assisted extractions. The results from the physicochemical properties of the oils were as follows: specific gravity, 0.876 g/mL, 0.843 g/mL and 0.865 g/mL for AH, GL, and MO. The free fatty acid contents of the oils were 0.436% FFA, 0.547% FFA and 1.60% FFA for AH, GL, and MO respectively. The saponification values gave 143.03 mgKOH/g, 72.93 mgKOH/g, 126.22 mgKOH/g for AH, GL and MO in that order. Iodine values for the oils were 46.54 mgI2/g, 22.41 mgI2/g, 68.10 mgI2/g for AH, GL, and MO, respectively. The peroxide values gave 10.05 meq/kg, 8.50 meq/kg, 8.0 meq/kg for AH, GL, and MO, respectively. The kinematic viscosities were 21.0 mm2/s, 22.0 mm2/s and 43.0 mm2/s for AH, GL, and MO, respectively. The acid catalyzed reaction gave greater crude yields of 90.00% for all three plants while the base catalyzed reaction gave, 87.00% (AH), 84.00% (GL) and 74.00% (MO). The purified biodiesel samples had the following acid numbers: 0.028% FFA for BAH, 0.022% FFA for BGL, and 0.028% FFA for BMO. The kinematic viscosities values for biodiesel were 4.00 mm2/s, 4.23 mm2/s, and 5.22 mm2/s for BAH, BGL, and BMO, respectively. The cetane numbers of the synthesized biodiesel samples were 142.73 (BAH), 167.29 (BGL), and 82.40 (BMO). The IR spectra of the biodiesels corroborated the chemical make-up of biodiesel. Hence non-edible seed oils from the Cameroon rich bioresources can be valorized in biodiesel synthesis and other forms of green energy production in Cameroon and beyond.