Biodiesel Synthesis from Waste Cooking Oil Using Periwinkle Shells as Catalyst

Waste materials such as periwinkle shells (PS) and waste cooking oil (WCO) were considered as heterogeneous catalyst and renewable feedstock for biodiesel production respectively in line with the current search for alternatives of the environmentally unfriendly and gradually depleting fossil fuel. PS were size reduced and calcined at 673K for 4 hours to remove carbonaceous and volatile matter in the sample. Physicochemical analyses on the WCO revealed high FFA (2.81%) therefore the need for esterification (0.42%). One factor at a time (OFAT) results show that methanol to oil ratio, catalyst loading, reaction temperature and time had significant effect on the biodisel yield. The transesterification reaction kinetics data was modelled using the zero-order, pseudo-first order and pseudo-second order models. The results presented from the error functions: root mean square error (RMSE), chi-square (χ2), mean absolute error(MAE) and coefficient of determination (R2) adjudged that the pseudo-first order model best described the process. An activation energy of 16.47 KJ/mol was obtained. Gas chromatography result revealed that a biodiesel yield of 73.92% was achieved at 8:1 methanol to oil ratio, 1% catalyst loading, 300 rpm stirring speed, 333K reaction temperature and 90 minutes contact time. The findings suggest potentials of PS as a viable catalyst for biodiesel production.