Biodiesel Production Using Calcined Phosphate Rock as a Precursor of Calcium Oxide Heterogeneous Catalyst

Abstract In this paper, phosphate rock has been utilized beyond its traditional role as a raw material for fertilizer production to a new potential role as a heterogeneous base catalyst for biodiesel production. The rock was thermally modified through calcination at 900 °C for 8 hrs. One factor at a time experimental design was used to vary the operating conditions of time (30–150 min), temperature (40 °C–80 °C,) catalyst concentration (1–5 wt%), and methanol to oil ratio (10–50 wt%). It was established that the optimum production conditions for maximum biodiesel yield of 93 % using this novel catalyst was achieved at reaction time 90 min, reaction temperature 60 °C, catalyst concentration 3wt% and methanol to oil weight ratio of 30 wt%. The synthesized biodiesel was compared with the raw waste oil using Fourier transform infrared spectroscopy (FTIR) to determine the efficiency of conversion from this catalyst. The catalyst modification after calcination was also analysed using this spectroscopic technique to confirm any changes in the functional groups. Biodiesel’s chemical and physical properties were measured based on the American Society for Testing and Materials (ASTM) international standards for biodiesel.