Pilot project turns corn husks, stalks, leaves into jet fuel

Corn stalks and waste, lying in the field.
Corn waste, or stover, is being turned into jet fuel as part of a national research effort involving WSU scientists.

Left behind after summer’s harvest, corn’s bulky stalks, rustling leaves, husks, and silks offer few uses beyond low-quality livestock feed, or being plowed back into the soil.

Researchers at Washington State University are part of a national effort to find a higher-value use for such leftovers. The waste, also known as corn stover, is a plentiful source of lignin, a structural molecule used to make advanced jet fuels.

Bin Yang, associate professor in WSU’s Department of Biological Systems Engineering, is helping to launch a new $3.7 million, U.S. Department of Energy (DOE)-funded project, led by researchers at the University of North Dakota. The team will design, build, and test a lignin-based pilot reactor, for the first time studying the commercial viability of the process.

Based at the Bioproducts, Sciences, and Engineering Laboratory at WSU Tri-Cities, Yang and his colleagues previously developed a catalyst to produce lignin-based jet fuel that contains cyclic hydrocarbons—molecules with favorable emission performance that help meet sustainable fuel requirements.

The national team’s pilot project takes their process from the laboratory workbench to the cusp of production. If successful, the next step is design and construction of a full-size demonstration plant.

“This opens the door to aromatics-free jet fuels that combine very low emissions with high performance,” Yang said.

Most corn stover is left in the field to help replenish the soil, but about 30 percent can be harvested for other uses, including lignin-based biofuels.

Bin Yang, arms crossed, standing in front of wall.
Bin Yang, Associate Professor, Biological Systems Engineering.

“Lignin is the polymers that lend strength and rigidity to corn and other plants,” Yang said. “It can be broken down and reassembled into a high performance, completely sustainable jet fuel to help us meet our nation’s energy and sustainability goals.”

In this project, corn stover bales will be preprocessed in collaboration with DOE’s Idaho National Laboratory. Scientists at the National Renewable Energy Laboratory in Colorado will then use mechanical and chemical refining processes to produce lignin from stover. It will then be converted to fuel on a pilot scale at the University of North Dakota, using the catalyst and process developed at WSU.

Yang’s research team will also be working with a commercial partner, Advanced Refining Technology (ART), to develop and test an improved catalyst, increasing yield and selectivity for cyclohexanes and other desired fuel molecules.

Team members will develop both commercial catalysts, optimize how to use them in a continuous reactor, determine the technical and economic potential of the method, and estimate the reduction in greenhouse gas emissions through use of this renewable jet fuel.

“Sustainable fuels are the future of aviation,” Yang said. “While challenges remain, investment in biofuels from lignin sources like stover could bring environmental and economic benefits, while providing new value to agriculture.”

Project leaders include University of North Dakota scientists Wayne Seames, Alena Kubatova, and Bethany Klemetsrud; Xiaowen Chen with the National Renewable Energy Laboratory; Allison Ray with Idaho National Laboratory; Joshua Heyne, University of Dayton, and Darryl Klein with industrial partner Advanced Refining Technologies.