Advancements in agriculture continue to move at a supersonic pace. One of the latest developments: jet fuel made from corn.
Corn-based Sustainable Aviation Fuel (SAF) takes biofuels to a new level beyond ethanol production. It actually begins with ethanol, which is then enhanced via “Alcohol-to-Jet” pathways to form a fuel suitable for aviation.
According to the American Coalition for Ethanol, SAF is “a renewable alternative to conventional jet fuel that could be used in today’s aircraft and immediately improve the environmental impact of flight.” Relying on renewable sources like corn, SAF is said to deliver equivalent performance to petroleum-based jet fuel with a fraction of its carbon footprint, and is suitable to use in today’s existing aircraft engines and infrastructure.
At an estimated 80% reduction in overall CO2 lifecycle emissions compared to fossil fuels, SAF promises to drive the “decarbonization” of air travel.
Like ethanol, corn-based SAF could yield massive quantities of co-products. The U.S. livestock industry is poised to embrace those resources, according to Dr. Kurt Rosentrater, Professor of Agricultural and Biosystems Engineering at Iowa State University.
On a recent episode of The Dairy Podcast Show, Rosentrater noted that after just two decades, dried distillers grains with solubles (DDGS) have become a widely implemented staple in animal nutrition.
“When the ethanol industry was in its earliest stages, I remember having conversations with companies saying, ‘in a couple of years, we’re going to be dealing with 10 million tons of DDGS. What are we going to do with all of that? We’re going to have to burn it and landfill it,’” he recalled. “Well, right now we’re sitting at about 33-35 million tons per year, and we’re not landfilling it, we’re not burning it. We’re using it in beef, dairy, swine, fish, and pet foods, plus we’re exporting about a third of it.”
Rosentrater credited dairy and livestock nutritionists with optimizing ingredients like DDGS for a variety of species. At the same time, ethanol manufacturers have fine-tuned production practices to create more consistent, specialized, and high-quality co-products.
He expects that same ingenuity to prevail if corn (and also potentially soybeans) is channeled at a large scale into SAF production. “In the past few years, there has been a big push among lots of different organizations about the idea of the ‘circular economy,’” he shared. “I laugh at that, because, in agriculture, we’ve been doing the circular economy for generations.”
The first commercial-scale facility converting U.S. corn into SAF is currently slated to be in the dairy-boom state of South Dakota. Gevo’s Net-Zero 1 plant near Lake Preston, SD, is projected to produce an estimated annual 60 million gallons of SAF, plus an accompanying 1.32 billion pounds of protein and animal feed and 30 million pounds of corn oil.
Although the South Dakota plant was initially slated to begin production in 2025, delays in financing and carbon pipeline approval/access have stalled the project.
Still, proponents of SAF note that airlines have already made commitments to purchase sustainable fuels to offset their carbon footprints. And they argue that using only the starch fraction of corn for fuel, while preserving the protein and nutrients for livestock feed, helps negate “fuel-versus- fuel” debates.
