Production of biodiesel from waste oil using a catalyst synthesized from waste clam shell

Abstract

An investigation into biodiesel production from waste vegetable oil using a catalyst synthesized from waste clam (Mercenaria mercenaria) shells was carried out. The clam shells were thermally decomposed at 800 °C for 5 h and its properties were characterized with SEM and XRF. It is composed of 30.88 wt.% CaO and other basic oxides catalysts known to be active in transesterification; and a surface morphology indicating pores in the catalyst. The transesterification reaction was conducted and the effect of alcohol to oil molar ratio, catalyst concentration, reaction time and temperature on the yield of the biodiesel were determined. Maximum biodiesel yield of 76.18 wt. % was realized at 60 °C, 9:1 molar ratio of alcohol to oil, a catalyst concentration of 3 wt.% in a reaction time of 2 h. The FTIR studies of the biodiesel showed that it is composed of alkanes, aromatics, alcohols and the physiochemical properties, namely density, viscosity and flash point are 0.897 g/mL, 3.9 mm² /s and 152.8 °C, respectively; falls within the biodiesel ASTM specifications.