Ethanol Producer Magazine March 2025
By Lisa Gibson
New Energy Blue has its sights set on a 20 MMGy biomass refinery in Mason City, Iowa, using corn stover as a feedstock and pumping out cellulosic ethanol and lignin by early 2027.
Drawing on decades of experience with partners in Scandinavia in handling and processing agricultural waste, New Energy Blue is confident that it can overcome the obstacles faced by previous corn stover ethanol producers, namely preprocessing for optimized physical properties and quality control.
Through a $2 million U.S. Department of Energy Collaborative Research and Development Agreement, New Energy Blue, Idaho National Laboratory, National Renewable Energy Laboratory, Finland-based Valmet and West Salem Machinery of Oregon will work to integrate processing and hydrothermal pretreatment of corn stover to produce biochemicals and fuels.
“It’s important to consider quality of feedstock coming into the plant,” says Kelly Davis, vice president of New Energy Blue. Previous attempts at corn stover cellulosic ethanol production did not take the time to develop proper systems to ensure the feedstock works efficiently through the entire process, says Tom Corle, founding partner, chairman and CEO of New Energy Blue. “So we have spent a decade working on that and, in the past two years, we’ve invested well over $1 million around equipment and aggregation practices to be able to accomplish what we’re looking to do at our facility.”
“This is a new startup, but yet it’s not,” Davis says. “We’ve done our homework for the past 10 to 12 years and the process has scaled up 10 times every time. Now, we’re scaling up 10 times again, but it’ll be a full commercial facility.” Mason City will be the flagship, “but by the time we’re digging ground in Mason City, Tom will be out looking to build our second facility.”
Optimal Physical Properties
“INL’s role is going to be separation, fractionation, during the processing of the corn stover to generate blends that have the right physical properties, and we will then test the flowability of these properties—how they perform during some pretreatment processes,” says John Aston, staff engineer in INL’s Biological and Chemical Processing Department. “The purpose of the process is to tailor feedstock into specific physical properties that can perform better during pretreatment or during handling and feeding of the material to the pretreatment.”
New Energy Blue, specifically, is using a feeding system centered around a compression screw feeder, Aston explains. The right consistency is vital: too loosely packed and the material will roll out of the system; too tightly packed and the system will seize up, requiring shutdown and increased maintenance costs. “In the right consistency, we need the right balance of fines in the material, right particle shape, particle size distribution and ash content,” Aston says.
About 200 million tons of corn stover are available annually that could be used sustainably to make fuel, he says. Lynn Wendt, INL senior research scientist, says, “It is currently just harder than the corn grain because it is more complex, essentially, so industry has struggled to use corn stover to this date and the work that we’re doing up front in preprocessing is an attempt to solve some of the challenges with flowability, with variability of the material.”
Wendt and Aston are working specifically on air classification for fractionation. It’s a particularly promising practice for corn stover feedstock with its anatomically diverse properties, Aston says. The leaf and husk have lower densities than the cob, so an air stream is an effective way to separate the stalk from the cob. “Once you understand the specific material you’re working with, especially the moisture content, you can get in and start to separate the leaf from the husk,” Aston says.
The INL team started evaluating air classification more than 10 years ago, initially on logging and forestry feedstock materials, as a means of removing dirt and ash. Passing that material through an air classifier screened out the lighter, dry soil and dust. “Once you achieve those separations, you then start to look at formulations for different systems,” Aston says.
“One of the advantages of air separation is they have a very low energy consumption, so they don’t cost a lot of money, but you can improve the quality of the material quite significantly,” Wendt says.
“I think if we can demonstrate at the pre-pilot scale, which is the scale of our facility, we could accomplish quality improvement with air separation of corn stover, that … would be a valuable tool,” she adds. “There’s a pathway of pre-pilot work that will happen in the next couple of years, then we see that moving on to more demonstration and then finally commercial scale. It is doable.”
In addition to the fractionation benefits, the quality control potential in the research is of vital interest to New Energy Blue. “We are all looking to optimize that feedstock area to the most efficiency, like the movement of the bales and cleaning of bales. For instance any rot, foreign matter, rubber tires, anything else that might be buried into a bale, that all gets removed,” Corle says.
“The work with INL will be with bales to understand preprocessing better,” Davis adds. “They can help us improve when we build our second and third facilities.”
Partnerships and Processes
New Energy Blue will source its corn stover feedstock from a 30-mile radius of its Mason City location. A farmer-owned partnership program—New Energy Farmers—will help control bale quality before the INL process is ready for implementation, while nurturing relationships with area farmers in a profit-sharing model. “It’s very unique,” Corle says. “It’s like a hybrid co-op.” He adds that the company has already contracted the feedstock it will need.
Investments into corn stover aggregation have allowed an increase in bale size from 900 pounds to 1,400 pounds, resulting in fewer bales needed, Corle says. “We’re able to do that more efficiently and drive down cost overall, but we’re also actually cutting that in the field as well.” New Energy Blue is working with equipment developers to design a specialized corn row header for cutting and chopping in the field. “All that creates less dust, less dirt and less energy use at the facility.”
The New Energy Farmers program will employ equipment and staff of about 60 balers who will cut, bale and stack the stover at the field’s edge, then transport it to strategically located storage barns. The refinery will house 3.5 to four days’ supply of bales on-site.
“All of the logistics are essential but the farmer buy-in and ownership of New Energy Farmers is also essential, simply because they need that revenue,” Corle says.
New Energy Blue’s front-end process for its Mason City plant was designed in Denmark and will be fully automated, utilizing cranes to unload stover bales from trucks, with a speed of about six minutes per truck, Corle says. “I can’t wait to show the ethanol industry these cranes and how they’re going to move these bales,” Davis adds.
From there, the process is simple, Corle explains. The plant will deploy heated reactors developed by Valmet. “We cook the biomass almost like cooking a potato, and it loosens up the sugars and the lignin walls that those sugars are attached to. We don’t use acid or ammonia, so we have a very clean process throughout.” he says.
The cooked stover then enters a hydrolysis system that utilizes enzymes. Albert Bryde Nielsen, product marketing manager for Novonesis, says the difference between enzymes for starch-based ethanol and for second-generation ethanol is that the former requires a low dosage of mainly amylase and glucoamylase to break down starch to glucose, while the latter uses a high dosage of many different types of enzymes, such as betaglucosidases, LPMOs, xylanases, betaxylosidases, cellobiohydrolases and endoglucanases.
“New Energy Blue’s plant in Mason City indeed could serve as a good U.S. model for second-generation ethanol using corn stover as substrate,” Nielsen says.
After hydrolysis comes fermentation, dehydration and evaporation, all similar to that of a first-generation ethanol plant except with a longer fermentation retention time. “The process works the same with the molecule,” Corle says.
End Product Revolution
New Energy Blue’s corn stover biorefinery will pump out 150,000 tons of lignin annually, and almost half of its cellulosic ethanol will be used to produce bioethylene for biobased plastics.
Lignin is a high-value substance, Davis and Corle say, with immediate use in asphalt and road resurfacing markets. New Energy Blue has many years of research experience in the lignin-for-asphalt space in Europe.
“Cellulosic ethanol producers want to burn lignin for power but it has a far more valuable use,” Davis says. “In the future, certain lignin fractions will be even more valuable than paving roads with it.
“Our objective is not building a second-generation ethanol plant,” she adds. “We are building a biomass biorefinery. Lignin will drive revenue to the facility from further refined products in the future.”
With lignin separation, the biorefinery can likely achieve a carbon intensity score of -50 and possibly -100 grams of carbon dioxide equivalent per megajoule through the GREET model.
To provide for bioethylene production, New Energy Blue will construct a cellulosic ethanol-to-bioethylene conversion facility on its Port Lavaca, Texas, property. The bioethylene produced there will go to a partner, Dow, via pipeline. The site was selected for its proximity to Dow’s U.S. Gulf Coast operations.
“When I go out and talk about our biomass conversion process, most people are more interested in the bioethylene side than our second-generation ethanol,” Davis says. “We know we can go to California with second-generation ethanol, but I became very intrigued by the bioplastics side because I know that ethanol needs new uses.”
The campus will also feature a biotechnology laboratory for up-and-coming technologies, as well as for further research and training on operating such a facility.
But policy remains a hurdle, both Davis and Corle say. “Renewable chemicals don’t have any incentives,” Davis says. “All the incentives are going toward the fuel world. So we need to work with Washington a little better, with this next administration, to make it possible for us to start making renewable chemicals to replace fossil fuels.”
Corle adds, “We need to focus on chemicals because if you want a third of that biomass, which is lignin, going into other valuable products … we need to have better policies in this country. That’s what’s going to have the pull through. This could go even faster than when ethanol was built out in a decade with policy support, with that great policy beyond just fuels.”
In the meantime, Davis says, “We’re having a lot of fun with the future separation of products into other chemicals. … It’s not like when we started making ethanol and nobody wanted us—we had to push our way in. This is different. There is a consumer pull, and we’re enjoying that right now.”
New Energy Blue’s Mason City biorefinery will help bring visibility to the potential of lignin in renewables markets, but also to corn stover as a biofuel and chemicals feedstock.
“We need to do this first project right and we know how to do it, but the whole world needs to see it completed and that’s our focus currently,” Corle says.
Author: Lisa Gibson
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