Nitric Acid-Impregnated Activated Carbon from Palm Kernel Shell as Heterogeneous Catalyst for Biodiesel Production from Waste Cooking Oil

The ever-increasing energy demand and gradual depletion of fossil fuels, together with environment concerns, the exploration of alternative source of energy such as biodiesel is gaining considerable attention. However, the high cost of feedstock limits the commercialization of biodiesel compared to conventional diesel. Thus, the utilization of waste cooking oil in the biodiesel production can reduce the total production cost as well solving the disposal problem. In the present work, heterogeneous acid catalysts were studied to develop an effective catalyst for biodiesel production from waste cooking oil of high free fatty acid content with improved catalytic activity and stability. The dried palm kernel shell was calcined in a muffle furnace at 500 oC after impregnated with HNO3 at different concentration. The catalysts then were characterized by various analytical techniques such as N2 adsorption-desorption, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and BET surface area and pore size analyzer to explore their physicochemical properties.