The development of fly ash-supported CaO derived from mollusk shell of Anadara granosa and Paphia undulata as heterogeneous CaO catalyst in biodiesel synthesis

The aim of this study was to develop fly ash-supported CaO catalyst derived from waste mollusk shell of Anadara granosa and Paphia undulata for transesterification of palm oil to yield biodiesel. The active precursor Ca(OH) 2 of the catalyst has been developed from calcination of waste mollusk shell, while the mesoporous has been prepared using the wet impregnation method. The results demonstrated that the mollusk shell-derived catalyst could gain the yield of biodiesel of 92 and 94 % for A. granosa shell and P. undulata shell, respectively. The obtained yield was comparable with the yield of biodiesel gained from CaO catalyst derived from reagent grade CaCO 3 (yield = 94 %). The optimum condition was achieved at catalyst loading of 6 %, reaction temperature of 60 °C and reaction time of 2 h. The reusability study showed that the developed catalysts exhibited higher recycle degree characteristic indicated by 50 % yield reduction after three reuse cycles.