Abstract
This research study synthesized a base catalyst from the waste Citrullus lanatus rind (WCLR) for the synthesis of biodiesel from the waste pig fat oil. The high-acid-value oil (high free fatty acid: FFA) was converted to low-acid-value oil through adsorption in sorghum bagasse ash with high particle sizes. The developed base catalyst was obtained from the WCLR and was characterized via thermogravimetric analysis (TGA), Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD-FT), and Brunauer-Emmett-Teller (BET) adsorption analysis. The properties of biodiesel were compared with the recommended standard. Results reflected that the duroc breed pig fat is rich in oil, and the oil is unsaturated. Sorghum bagasse proved to be a good bio-adsorbent for the unsaturated fat FFA reduction. The catalyst produced from WCLR was found to be rich in potassium-calcium-magnesium (K-Ca-Mg) base salts. The predicted yield of 98.69 % (wt./wt.) at 69.96 min, 79.93 °C, 3.15 % (wt.), and 8.57 (vol.) at desirability of 100 % was validated as 98.52 % (wt./wt.). Catalytic strength can be recycled in five cycles. The cost implications indicated that the cost of producing 25 L of biodiesel is $2.61. This study proved to be the most economical way of producing biodiesel that is environmentally friendly, cost-effective, and easy to produce for future energy needs.•Oil was obtained via rendering from duroc breed waste fat oil.•Sorghum bagasse was used as adsorbent for acid reduction of high FFA pig fat oil.•Base catalyst used was obtained from calcined waste Citrullus lanatus rind.