Application of Supercritical Fluids Extraction and Methylation on Production of Biodiesel from Plant Seeds pp. 195-214
Authors: (Chao-Rui Chen, Chieh-Ming J. Chang, Wei-Heng Chen, Ching-Hung Chen, Department of Chemical Engineering, National Chung Hsing University, Taichung, Taiwan, ROC)
Abstract: This study examined the effects of pressure, temperature and solvent to solid ratio (SSR) on extraction efficiency of triglycerides from powdered Jatropha curcas seeds and Aquilaria crassna seeds by using supercritical carbon dioxide (SC-CO2) extraction. According to the results of response surface methodology, pressure presented more effective in increasing the recovery of triglycerides, but both temperature and the SSR value are important in obtaining high concentration of triglycerides from two plant seeds that are useful for biodiesel materials. The experimental equilibrium solubilities of these two oils dissolved in SC-CO2 at temperatures of 318–338 K and pressures of 200–350 bar were also investigated. The results indicated that the solubility of the oils linearly increased with the density of SC-CO2 and the experimental data were successfully correlated by the Chrastil equation. Finally, this study demonstrated that subcritical hydrolysis followed by supercritical methylation of the SC-CO2 extracted oil is a feasible two-step process in producing a 98.5% purity level of biodiesel from Jatropha curcas kernels.