(612e) Physicochemical Properties of Pyrolytic Lignins Derived From Fast Pyrolysis of Etek Lignin


Producing bio-based chemicals as part of the thermochemical process technologies is becoming increasingly relevant to product diversification envisioned for biofuels and biobased product development. The idea of utilizing the high molecular weight lignin-like oligomers (pyrolytic lignin) in biomass derived fast pyrolysis oil as potential feedstock for the production of renewable chemicals instead of fuels has been discussed. However, the potential of using lignin-rich byproducts in the fast pyrolysis feedstock-to-chemical value chain is yet to be explored. In this study, commercial Etek lignin was subjected to a fluidized bed fast pyrolysis yielding a dark pyrolysate. Following a soxhlet extraction to remove interfering chemicals, subsequent water extraction allowed the fractionation of pyrolysis oil into water-soluble and water-insoluble pyrolytic lignins. Based on the variability in their solubility, pyrolytic lignins were separated into different fractions (ethanol-insoluble, water-insoluble, dichloromethane-insoluble, and dichloromethane-soluble) having different specific molecular weights. The resulting lignin fractions were characterized by elemental analysis, gel permeation chromatography, 31P-NMR, ATR-FTIR, TGA, and scanning electron microscopy. By analyzing the extent of lignin degradation under thermal treatment with the various analytical techniques, we were able to establish the differences in their chemical structure, molecular weight and thermal behavior, and subsequently their potential utility as starting materials for the sustainable production of renewable chemicals and fuels.