Beyond Corn Oil Extraction

A new corn oil technology developed by a fluid purification company offers multiple coproducts, improved ethanol yield and water balance, and other benefits.
By Holly Jessen | April 08, 2014

Valicor Separation Technologies LLC has developed a new modular system that doesn’t just extract one coproduct, it fractionates multiple coproducts, including more distillers corn oil as well as fiber and high protein animal feed. The company announced in late February that it had received a U.S. Patent and Trademark Office notice of allowance for its Valicor Stillage Fractionation Technology, known as VFrac.  Valicor already has Corn Oil Separation Systems, its first-generation corn oil separations technology, installed at 40 ethanol plants. As of March, the company was building its VFrac modular system at its Dexter, Mich., facility in advance of instillation at two dry mill ethanol plants. “Following midyear startup, we should have some good operating data on both the ICM plants as well as the Delta Ts,” says Chris Mahoney, director of Valicor’s advanced separations group.

The $4.5 million fractionation system has a 12- to 18- month payback. In addition, it’s complimentary to fine grind technology. Ethanol plants with front-end fine grind systems already installed won’t have issues with higher suspended solids, or fines, and can gain the benefits of VFrac with one fewer module installed. “It actually reduces the cost of our system,” Mahoney says.

The company got its start in 1997 as Solution Recovery Services, separating and purifying industrial fluids. Today, Valicor is 100 percent employee-owned and has continued working in the industrial space while also diversifying into food and beverages, as well as the pharmaceutical and nutraceutical industries. About eight years ago, the company began working on biofuels technologies, starting with biodiesel and then moving into ethanol, says Tom Czartoski, president, CEO and co-founder of the company.
Specifically, it was the company’s work on separation technologies for algae that led Valicor down the path of corn oil recovery. “We put a considerable effort into microalgae, and microalgae was an interesting challenge by way of a single cell that contains proteins, carbohydrates and oils. And we focused on developing a technology to accommodate those compounds, or separate them into streams,” he says. “Those developments led us back into the ethanol space to apply that technique to separating proteins and separating oil.”

Big Benefits
In developing its second generation corn oil technology, Valicor achieved several goals. The first was to develop a process that works outside the midevaporator, to avoid any confusion with existing corn oil technologies. As a result, VFRAC separates corn oil from stillage, not concentrated stillage. “We wanted to move away from the patent litigation and all the legal issues that surrounded all that,” says Douglas Corey, industry manager, who started working for the company when there were only eight employees.

After speaking to ethanol producers, Valicor identified key concerns for the new technology. The first was maximizing coproduct revenue, not just through corn oil recovery, but other coproducts as well. Another goal was improving ethanol fermentation. The energy efficiency and operation of the evaporator train were also targets. Finally, the company aimed for preparing for the next stage of cellulosic and clean fiber technologies, once they become a reality. “We call it a forward compatible technology because where it is in the whole stillage stream it really lets you get at those cool things in the kernel of corn,” says Phil Schoof, senior vice president.

The technology’s hydrothermal treatment allows for separation of more corn oil. In fact, VFrac can pull out 1.2 pounds of corn oil per bushel of corn. And that’s without the use of any additional chemicals to increase yield. “This technology does away with that operating expense need,” Schoof says.
A key feature of the technology is tunability—or the option to separate more or less corn oil, depending on market demands. Most customers only want to take out about 1 pound per bushel of corn oil, leaving 7 percent fat content in the distillers grains, Mahoney says. That allows plants serving different feed markets, which prefer different fat levels in distillers grains, to aim for different corn oil content targets, adds James Bleyer, Valicor program manager, leader of the company’s biofuels R&D division and inventor of VFrac.

The technology is also tunable in the amount of high protein meal, or VPro, it separates. This additional coproduct is similar to corn gluten meal produced at a wet mill. “We want to pull out enough protein to create this high-value protein product without being deleterious to the existing DDG production,” Bleyer says. “In other words, the existing DDGs have a certain specification that has to be met and, just like we don’t want to pull out too much of the oil, we don’t want to pull out too much of the protein, so that DDG won’t meet that spec.” 

Separating out the high protein VPro reduces total distillers grains volume by about 10 percent, says Jennifer Aurandt, technology development program manager. The new coproduct contains about 50 percent protein, about 8 percent oil and is lower in fiber than distillers grains. Early feed trials done at the University of Georgia show VPro has higher total metabolizable energy and increased lysine availability. “We’re excited about this high protein meal and the fact that we can tune it to what the industry likes,” she says. “If they want less oil, like corn gluten meal, if they want more oil, whatever the animal nutritionist needs to formulate their diet.”

The separations process also creates stickwater, a low-solids liquid stream, fractionated from the whole stillage, Bleyer says. Recycling stickwater in the evaporator train, for example, has advantages over using thin stillage, which makes evaporators prone to fouling and less energy efficient. Stickwater can also be recycled to the front of the ethanol plant, where the reduced solids mean the ethanol plant can process more corn while maintaining the same target solids levels in the cook process, he said. All in all, the VFrac technology allows for better water balance.

In fact, sending cleaner recycled water to the front of the plant actually results in better fermentation, Mahoney says. While the number can vary, depending on the amount of residual starches a plant has, testing has shown the technology can result in a 1 to even 2 percent increase in ethanol yield.

Finally, the technology is able to remove fiber, which can be used as a cellulosic ethanol feedstock, among other things. “There’s other high-value opportunities for that fiber, other than cellulosic ethanol, currently under development, Bleyer says. “It could be an important coproduct for an ethanol plant in the future.”

Valicor is continuing R&D in separating different components of the corn kernel and different applications for the coproducts. On the corn oil side, currently, the two big demand drivers for the coproduct are the animal feed industry, specifically poultry, and biodiesel plants. “If we can make products that are better for either one of those customers, that’s a great value add,” Aurandt says.

Corey considers VFrac part of the next evolution of the ethanol industry. “I think you are going to see that the dry mill ethanol market, the longer it exists, the more it matures, will move the coproduct stream much closer to what you find in a wet mill ethanol market,” he says. “It’s only the natural progression.”

Author: Holly Jessen
Managing Editor, Ethanol Producer Magazine