Supercritical carbon dioxide extracted oil from Jatropha curcas: directive for the biodiesel industry?

Abstract

Jatropha curcas oil was extracted from seed by supercritical carbon dioxide (sc-CO2) and converted to a biodiesel in support of a world-wide search for a sustainable energy source produced by clean technology to replace rapidly dwindling fossil fuel resources. Analysis of the extracted oil by one-dimensional and two-dimensional gas chromatography with time-of-flight mass spectrometric detection (GC × GC–TOFMS) before and after transesterification to fatty acid methyl esters (FAMEs) proved that the composition of the final converted product correlated well with that of a commercial biodiesel standard. In addition, the oil content of the seed, the solubility of the oil in sc-CO2, and some physico-chemical properties (activation parameters, density dependence) of extraction of the oil by sc-CO2 were studied to support further the viability of J. curcas as a biofuel source. Finally, sc-CO2-derived Jatropha oil was compared to that obtained by classical soxhlet extraction and by two other non-classical methods (microwave-assisted superheating, ultrasound-supported extraction) meeting the requirements of green chemistry.