ABSTRACT
The challenges of continual depletion, economic crisis and environmental issues of the petroleum fuels have attracted the scientists' interest to seek for alternatives to fossil fuels.Biodiesel is the alternative to petrol diesel because; it has similar physicochemical properties to petrol diesel. However, biodiesel has not been competing favourably well economically with petrol diesel due to high cost of production.In this work, biodiesel was produced from waste cooking oil (WCO) using modified kaolinite clay as a heterogeneous acid catalyst. Kaolinite clay sourced from Kankara town in Katsina State was beneficiated, calcined and acidified to produce the catalyst. The catalyst was characterised using X-ray Fluorescence(XRF), X-ray Diffraction(XRD) and Scanning Electron Microscopy(SEM).The effect of the following variables namely: Silica to alumina mass ratio, reaction temperature, methanol to oil ratio, reaction time and catalyst dosage were studied. Important fuel properties such as viscosity, acid value, density and flash point were determined and compared with ASTMD6571 standard for biodiesel. The catalyst was found to retain its catalytic properties even after reuse for four runs. The optimum conditions for biodiesel production were; reaction temperature of60�C, amount of catalyst of 4wt %, methanol to oil molar ratio of 15: 1 and reaction time of 120 min. The optimum yield of biodiesel was 92.7%. The results showed that the important fuel properties of the biodiesel produced at optimum conditions; viscosity (2.5cP), acid value (0.35), cetane number (53.7), flash point (1540C) and density (0.86g/cm3)met the biodiesel ASTM D6571 standard.