Development of a Novel Mesoporous Biocatalyst Derived from Kola Nut Pod Husk for Conversion of Kariya Seed Oil to Methyl Esters: A Case of Synthesis, Modeling and Optimization Studies

A base heterogeneous catalyst was prepared from kola nut pod husk which was subsequently applied to conversion of Kariya seed oil (KSO) to produce biodiesel via transesterification process. Characterization of the developed catalyst was performed using scanning electron microscope–energy dispersive X-ray (SEM–EDX), X-ray diffraction (XRD) and Brunauer–Emmett–Teller (BET) analysis. The central composite design was used to produce 28 experimental conditions employed in investigating the individual and synergetic influence of the process input parameters viz. methanol/KSO oil molar ratio, catalyst loading level and process reaction time on Kariya oil methyl esters (KOME) yield. The process input parameters examined were optimized using statistical approach through response surface methodology. The characterization of the catalyst developed showed that its catalytic activity was due largely to its high level of K and Ca. The best reaction condition for the transesterification process was found to be methanol/KSO molar ratio of 6:1, catalyst loading level of 3 wt% and process reaction time of 75 min at reaction temperature of 65 °C which led to maximum KOME yield of 98.67 ± 0.01 wt%. The results of various statistics employed in testing the model developed indicate that it is accurate and reliable. The study shows that the catalyst can be re-used up to four times.