(64c) Production of Sustainable Aviation Fuels from Lignocellulosic Biomass Feedstocks

Decarbonization is a major thrust area worldwide to reduce carbon emissions and therefore reduce potential global warming. Aviation is a very important transportation industry in the world which faces decarbonization challenge. Unlike road transportation which is being electrified, electrification of air transport is near impossible. The alternative to decarbonizing air transport is through the production and utilization of low carbon fuels. Current aviation fuels are produced mostly from petroleum resources and a small fraction from biobased resources such as plant lipids and algae lipids which are not sustainable. Efforts to produce aviation fuels from lignocellulosic biomass is often very challenging because fuels from lignocellulosic biomass pyrolysis oils are very rich in naphthenes and low in long chain aliphatic hydrocarbons which are major components of the petroleum derived aviation fuels. We have investigated the catalytic pyrolysis and hydrodeoxygenation of the pyrolysis oils to produce long chain hydrocarbons in the range suitable for aviation fuels. We have achieved the production of the long chain aliphatic hydrocarbons from biomass pyrolysis oils through alkylation and opening of the aromatic carbon rings. Carbonyl compounds were used to alkylate aromatic rings and then opened them into long chain aliphatic hydrocarbons. These reactions were catalyzed by nickel on red mud catalysts in aqueous medium. Thus, catalytic pyrolysis oils produced from pinyon juniper wood were successfully converted into aliphatic hydrocarbons and alkylated aromatic, and naphthenes suitable for application as aviation fuels. Carbon chain length ranged from C₆ to C₁₇ and both aqueous phase and organic phase pyrolysis oils were successfully used for the hydrocarbon production.