Abstract
Identification of better yielding nonedible feedstocks and process improvements with locally prepared chemicals is the way forward for improving biodiesel economic viability. Synthesis of fatty acid ethyl ester (FAEE) biodiesel from Croton macrostachyus hochst. ex delile (C. M.) seed oil is investigated through the transesterification method including oil extraction and CaO-chicken eggshell waste as a heterogeneous catalyst and ethanol, which has not yet been investigated earlier. The effects of catalyst load from 2% to 6% (w/w) of the weight of oil, ethanol to oil ratio from 9 : 1 to 12 : 1(v/v), reaction temperature from 60 to 80℃, and reaction time variation from 0.45 to 2 hr have been explored. The yield has been investigated, with the oil content of the C. M. seed being 46.85% realized through the solvent extraction route. The central composite design (CCD) using a design expert is employed to investigate the effects of different process parameters for biodiesel synthesis and to find the optimum conditions for maximizing the yield. The conversion to biodiesel via the calcium oxide-heterogeneous catalyzed transesterification route has achieved 91% yield under the optimum conditions. The optimum result predicted by the model is found to be 91.036% at a catalyst loading of 5.802 wt.%, reaction temperature of 76.117℃, a reaction time of 1.969 hr, and ethanol to oil molar ratio of 11.55 with a desirability value of 1.000. The FTIR spectrum confirms the composition and functional groups of synthesized biodiesel under optimum reaction conditions. Physicochemical properties of synthesized C. M. biodiesel are determined, and the results when compared with the biodiesel standard specifications are within the range prescribed. The result showed that C. M. could be a very viable feedstock for the biodiesel industry, which could be exploited as an alternative fuel source.