Production of biodiesel from Parinari polyandra B. seed oil using bio-based catalysts
Two agricultural residues, cocoa pod ash (CPA) and rice husk ash (RHA), were investigated as bio-based catalysts for the transesterification of Parinari polyandra seeds oil and the results obtained using these bio-based catalysts were compared with potassium hydroxide which is a conventional catalyst. Oil was extracted from parinari seeds and a yield of 57% was obtained. Cocoa pod and rice husks were ashed in muffle furnace at 600 oC and then characterized. Atomic Absorption Spectrometric analysis indicated the metal constituents of CPA as 13.05 ppm potassium, 6.65ppm sodium while RHA contained 3.24 ppm potassium, 1.748 ppm sodium, 0.053 ppm iron, 1.575 ppm magnesium, 2.325 ppm calcium and 0.009 ppm aluminum. Various concentrations of KOH, CPA and RHA (0.5- 0.4%) were investigated in the transesterification reactions. Methanol - to - oil ratio of 6:1 with 1% KOH, 2% RHA and 4% CPA catalysts gave good biodiesel yields. The biodiesel yields of 99.94%, 98.61% and 88.85% were obtained with 1% KOH, 4% CPA and 2% RHA catalysts respectively. The properties of the biodiesel produced were determined and found to fall within the ASTM specification for standard biodiesels.
Keywords: Biodiesel, parinari oil, cocoa pod ash, rice husk ash, transesterification