Pyrolytic Fractionation of Oleaginous Feedstocks

Traditional pyrolysis of oleaginous biomass results in bio-oils that contain a mixture of compounds derived from protein, starch and lipids – constitutive biopolymers of these feedstocks.  As a result, such biooils have to undergo energy-intensive denitrogenation and deoxygenation to render them suitable as fuels.  We have recently developed a “pyrolytic fractionation” technique based on the observation that the protein, starch and lipid portions undergo thermal degradation over distinct non-overlapping temperature intervals. Proteins are most thermally labile followed by starch and lipids.  Hence, conducting the pyrolysis in three temperature stages provides an opportunity to recover homogenous and biopolymer-specific biooils.  Bio-oils from protein and starch can find other applications, in addition being lower grade fuels.  For instance, N-rich biooil from protein can serve as a source of high value N-compounds and levoglucosans from starch pyrolysis could serve as precursors for value-added polymers.  Similarly, bio-oil from lipid fraction, predominantly containing free fatty acids, can be converted to fuels (such as biodiesel or hydrocarbons) or other higher value fatty acid derivatives. Finally, the bio-char can be a soil amendment.

In this presentation, results showing component-specific biooil compositions and yields from pyrolytic fractionation of algal biomass and oil seeds will be presented. We will also present a comparison of energy needs for pyrolytic fractionation relative to other themochemical methods for conversion of oleaginous feedstocks.