Kolanut pod husk as a biobase catalyst for fatty acid methyl ester production using Thevetia peruviana (Yellow oleander) seed oil

Abstract

The potential of kolanut pod husk as a biobase catalyst for the conversion of Thevetia peruviana (yellow oleander) seed oil to fatty acid methyl ester (FAME) in transesterification reactions was investigated. Oil was extracted from Thevetia peruviana (yellow oleander) seeds and a yield of 60 % was obtained. Kolanut pod husk was ashed in a muffle furnace at 600 °C and characterized. In producing the FAME, three concentrations (0.5, 1.0 and 1.5 wt %) of kolanut pod husk ash (KPHA) were investigated in transesterification reactions. Methanol to oil ratio was kept constant at 6:1 while temperature and time were varied at 40-60 °C and 60-120 min respectively. The design of experiments was used in the transesterification step to determine the effects of process variables on the yield of Thevetia peruviana methyl esters (TPME). The result showed the TPME was consistent with ASTM specifications for biodiesel. The best yield of 84.50 % was obtained for 1.5 wt % KHPA at a temperature of 60 °C and a time of 90 min. XRD and elemental analysis indicated that the catalytic effect of KHPA resulted from the presence of potassium and the microstructural formation from calcination at 600 °C. The study highlights the possibility of reducing the cost of production for FAME by using non edible vegetable oil and kolanut pod husk, an agricultural waste as a biobase catalyst in transesterification reactions.