The main aim of this work was to investigate the suitability of a KI/KIO3 impregnated hydroxyapatite (HAP) catalyst derived from natural phosphate rocks for biodiesel production. This study evaluated the effect of impregnation concentrations (1-6% w/w) on the catalyst performance in biodiesel production. The biodiesel was produced from waste cooking oil (WCO) under simultaneous esterification-transesterification reactions at 60 °C for 6 h. The results showed that the biodiesel yield increased by increasing impregnation concentration and the maximum yield (91.787%) was achieved at an impregnation concentration of 5% w/w. The KI/HAP catalyst showed better performance (91.78% biodiesel yield, 59.1% FAME yield and surface area of 13.513 m2/g) as compared to the KIO3/HAP catalyst (90.07% biodiesel yield, 55.0% FAME yield and surface area of 10.651 m2/g).
Keywords: HAP; biodiesel; impregnation KI/KIO3; simultaneous reaction; waste cooking oil.