In June 2015, United Airlines announced a partnership with biofuel company Fulcrum BioEnergy, to invest in future commercial scale aviation biofuel plants. The company’s innovative technology converts municipal solid waste (household trash) into low-cost, sustainable aviation biofuel. This investment adds to their agreement to purchase up to 15 million gallons of sustainable aviation biofuel from AltAir, over a three-year period. Photo courtesy of United Airlines.

Pacific Northwest National Laboratory (PNNL) and industry partner Lanzatech recently achieved a significant milestone in the production of renewable jet fuel. Funded by the Bioenergy Technologies Office (BETO), the project succeeded in producing five gallons of synthetic paraffinic kerosene from carbon-rich industrial waste gases (e.g., carbon monoxide). This process not only provides a viable source of sustainable jet fuel but also offers an innovative solution to industrial waste management. The accomplishment also demonstrates that their technology is ready for the next stage in testing on the road to commercialization.

The process works in two stages. First carbon-rich industrial waste gases are captured from manufacturing plants or refineries and fed to naturally occurring microbes called acetogens, or gas-fermenting organisms. These microbes consume the gas and produce ethanol (i.e., alcohol). However, the ethanol must undergo additional processing in order to be suitable for jet engines. In order to turn this alcohol into fuel that is chemically equivalent to petroleum-based jet fuels, the oxygen must first be removed and the remaining molecules must be combined into a larger, more energy-dense hydrocarbon.

This occurs during a second stage known as dehydration-oligomerization. During dehydration, ethanol is fed through PNNL’s specialized catalyst at elevated temperatures to produce ethylene and water. Ethylene then undergoes oligomerization to form a hydrocarbon that is similar in size to the molecules in petroleum-based jet fuels, yet does not lead to sooting when burned. The research team is now working to transfer this technology from the lab scale to industry use through a collaboration with Freedom Pines Biorefinery in Georgia. The next goal is to produce 2,000 gallons of jet fuel, as they continue to scale up their technology.

Sustainably produced advanced biofuels have the potential to deliver large quantities of cleaner fuel for aviation. Through this accomplishment, BETO, PNNL, and aviation industry partners are creating an increasingly vibrant and robust alternative jet fuel sector that will be part of a thriving bioeconomy.

The Office of Energy Efficiency and Renewable Energy success stories highlight the positive impact of its work with businesses, industry partners, universities, research labs, and other entities.