The new green catalysts derived from waste razor and surf clam shells for biodiesel production in a continuous reactor

A green catalyst has been derived from a waste material for transesterification of the Jatropha curcas oil feedstock for synthesis of biodiesel in a packed bed reactor (PBR). The razor and surf clam shells were crushed, ground, and calcined at 900 degrees C for 2 h to derive calcium oxide (CaO) as the economic and environmentally friendly catalysts. The heterogeneous catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence, scanning electron microscopy (SEM), and the Brunauer-Emmett-Teller method. The effects of reaction variables such as catalyst bed length (mass of catalyst), residence time (reaction time), reaction temperature, and methanol/oil molar ratio on the % yield of biodiesel were investigated. Long-term repeated operation of PBR was also examined. The optimum conditions were catalyst bed length 250 mm, residence time 1.5 h, reaction temperature 60 degrees C, and methanol/oil molar ratio 15:1 which yielded 98% of the conversion. The CaO catalyst could be used repeatedly for three cycles of methanolysis without activity loss and no activation treatment was required. The fuel properties of fatty acid methyl ester (FAME) were determined. The results indicated that the new green catalysts derived from razor and surf clam shells showed good catalytic performance and had high potential to be used as biodiesel production catalysts in transesterification of J. curcas oil with methanol.