(126a) Aromatic Hydrocarbons for Jet Fuels from Lignin Fast Pyrolysis and Upgrading

Cheng, F., New Mexico State University
Brewer, C. E., New Mexico State University

Jet fuels have never been entirely substituted by biomass (viz. bio-jet fuel) due to the absence of aromatic hydrocarbons and cycloparaffins in biomass-derived oils. Currently, this problem can only be mitigated by blending bio-jet fuel with at least 50% traditional petroleum-based jet fuels. To produce 100% non-petroleum-based jet fuels, a suitable source of bio-based aromatic hydrocarbons and cycloparaffins is needed. Lignin is the only component in biomass rich in benzene-ring structures linked via ether bonds. Lignin is frequently underutilized due to its heterogeneity and resistance to chemical conversion; most of the lignin extracted from biomass is burned as low-value, stationary energy.

In this paper, we explore the opportunity of a four-step pathway to convert lignin into jet-fuel-range molecules aromatic hydrocarbons and cycloparaffins. Once produced, these molecules can be blended with bio-jet fuels to create 100% non-petroleum-based jet fuel that meets the technical specifications of Jet A. The production pathway consists of four steps: biomass pretreatment, lignin depolymerization, hydrodeoxygenation (HDO), and alkylation. During biomass pretreatment, lignin will be the final product rather than a waste. During HDO, the two-phase bio-crude oil derived from lignin depolymerization is used as feedstock. The bottom phase, dominated by heavier phenols as the main components from depolymerization, will be targeted. The mixture of lignin-derived bio-oils from HDO will serve as the feedstock for alkylation. In addition, the mutual influences of multi-components on desired product yields will be considered in HDO and alkylation of lignin-derived bio-oil. The review on each process is conducive to direct the pathway optimization to produce jet-fuel-range molecules from lignin in future research through a simplified and integrated pathway.