Castor bean cake residues upgrading towards high added value products via fast catalytic pyrolysis

Castor oil is a vegetable oil obtained by pressing the seeds of the castor oil plant (Ricinus communis). Its production leads to high volumes of solid residues, the castor bean cakes. The main objective of this study was to investigate the potential of these castor bean cakes as a valuable source for production of high added value products such as bio-fuels and renewable chemicals. The upgrading of the castor bean cakes was attempted via thermochemical processes; specifically fast thermal and catalytic pyrolysis. Initially thermal pyrolysis of two different castor cakes and one type of castor stalks took place in a fixed bed fast pyrolysis reactor. The best feed was chosen for catalytic pyrolysis testing where industrially available microporous and one mesoporous catalyst were studied. Mass balances and products characterization via elemental analysis and two dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCxGC-TOFMS) in the case of the liquid products allowed for the estimation of the catalytic effect in each case.