WSU develops sustainable jet fuel from lignin waste
WSU develops sustainable jet fuel from lignin waste
Washington State University (WSU) scientists have developed a groundbreaking method to produce sustainable jet fuel from lignin, a major component of plant cells. This innovative research, published in Fuel Processing Technology introduces a continuous process that could revolutionize the production of aviation fuel by utilizing agricultural waste, specifically lignin polymers derived from corn stover – the stalks, cobs, and leaves left after harvest – and other byproducts. The research team, led by Bin Yang, professor in WSU’s Department of Biological Systems Engineering, demonstrated a process called “simultaneous depolymerization and hydrodeoxygenation.” This method breaks down lignin polymers while simultaneously removing oxygen, transforming the lignin into a usable jet fuel. Conducted at their Richland, Washington facility, the team introduced dissolved lignin polymer into a hydrotreating reactor, creating lignin-based jet fuel in a continuous, more commercially viable process.
This new approach holds significant potential for reducing aviation’s carbon footprint. In 2019, global aviation fuel consumption reached nearly 100 billion gallons, a figure expected to rise. Sustainable aviation fuels (SAFs) derived from plant biomass, like lignin, could help meet international carbon neutrality goals by minimizing emissions and reducing contrails, the condensation trails left by aircraft that contribute to climate change. Lignin-based jet fuel presents several advantages over fossil-derived alternatives, particularly in terms of fuel density and efficiency. Current aviation fuels rely on aromatic hydrocarbons, which enhance fuel performance but also contribute to environmental concerns. The lignin-derived hydrocarbons could replace these aromatics while still meeting the performance requirements for jet engines, including swelling O-rings in metal-to-metal joints, an essential function in engine sealing.
The study represents the team's first successful trial of continuous production using "engineered lignin," a form of less waste and less lignin. The results show that lignin is a useful source of cycloalkanes and other fuel compounds capable of increasing the density of fuel blends and purifying SAF more efficiently. The ultimate goal is to create 100% renewable jet fuel, meaning it can be used in airplanes without modification. With support from the US Department of Energy and other entities, the team is now focused on refining the process to improve efficiency and reduce costs, and bring commercial production of lignin-based jet fuels is closer to reality.