Putting wood or agricultural waste-derived sustainable aviation fuel (SAF) on an equal footing with conventional fossil fuel-based options will require reductions in production costs. An efficient process for the extraction and deconstruction of lignin from these starting materials offers a route to the attainment of cost-competitive SAF.

An innovative biomass pretreatment technology advanced by researchers from U.S. National Renewable Energy Laboratory, U.S. Oak Ridge National Laboratory, University of California Riverside and the University of Tennessee provides a path for cost-containment in SAF production. The co-solvent enhanced lignocellulosic fractionation (CELF) process adds tetrahydrofuran to water and dilute acid during biomass pre-treatment, efficiently fractionating biomass into clean hemicellulose sugars, cellulose and lignin intermediates. These components are then processed by diverse downstream conversion technologies to yield alcohols, esters, carboxylic acids and hydrocarbons as co-products.

As the CELF biorefining technology can more fully exploit plant matter than available methods, heavier, denser wood-based feedstocks are preferable over less carbon-dense corn stover for yielding greater economic and environmental benefits. By processing poplar wood in a CELF biorefinery, the researchers demonstrated that sustainable aviation fuel could be manufactured at a break-even price as low as $3.15 per gallon of gasoline equivalent. The current average cost for a gallon of jet fuel in the U.S. is $5.96.

CELF is also envisioned for use in the manufacture of renewable chemicals, which could serve as building blocks for bioplastics and food flavoring compounds. An additional benefit of the process described in Energy & Environmental Science is a reduced carbon footprint relative to current biorefining technologies.