Advances on the processing of Jatropha curcas towards a whole-crop biorefinery

Jatropha is still considered a strong candidate for the production of second generation biofuels, despite recent large-scale failures worldwide to achieve high and consistent seed yields on the field. A short term alternative for making jatropha-based businesses profitable under current modest seed yields is by harnessing the whole biomass under a biorefinery concept, using state-of-the-art technology. Several studies have explored various ways to harness the jatropha biomass as feedstock for diverse processes such as densification, pyrolysis, carbon activation, gasification, combustion, anaerobic digestion, fermentation, solid-state fermentation, and extraction and purification of compounds. In this review we consolidate the publicly available information and present an analysis of what seems the best way to integrate these processes under a biorefinery concept. A concrete proposal of a state-of-the-art jatropha-based whole-crop biorefinery is made, together with recommendations of further research required to fill the gaps that may lead to even more profitable jatropha-based whole-crop biorefinery systems.