Corn Plus - The ethanol option

In Winnebago, a small town in the south of the state of Minnesota, an ethanol producer called Corn Plus has teamed up with Alfa Laval to become one of the world’s top producers of ethanol.

DATE 2023-11-28 AUTHOR Jeanette Cézanne

They call Montana the “big sky country,” but the name could be equally well applied to southern Minnesota. Here, too, the land stretches out flat to the horizon, punctuated only by the occasional spinney of trees grouped around farmhouses. This is, after all, farming country – corn country. And in the middle of it all is a production facility turning the golden corn into another sort of gold: ethanol for fuel. Keith Kor, general manager of Corn Plus, couldn’t be happier. 

“I can’t imagine doing anything else,” he says.

A cooperative – and cooperating – industry

“We have 750 shareholders who are predominantly farmers,” says Keith Kor. “It’s a farmer-owned cooperative venture.” This means, he explains, that the farmers who supply the corn to the plant are also its shareholders. “If you own 5,000 shares, you’re expected to deliver 5,000 bushels of corn,” he adds. For those who cannot do so, a corn-pool service is provided. “The farmers that have invested in Corn Plus did so for corn prices are low. They will always get the average price of the corn and will hopefully get a ‘value added’ cheque at the end of the year,” notes Kor.

It is a curiously communitarian industry. “It used to be, when you heard about an ethanol plant shutting down, you went, Yes!” says Keith Kor. “You thought, we’re still going and we’re better than they were. But now it’s not that way, it’s everybody working together to make the industry grow, and that’s what it’s doing.” Adds Dell Hummel, senior sales engineer of Alfa Laval in the USA. “It’s a small world. Everyone knows everybody else, and there’s a sense of all being in this together.”

There is a definite sense of shared success in the industry. “We try to work together. If certain plants have problems they can call one of the other plants. Or,” he adds, with a definite twinkle in his eye, “for example, they might call to ask, ‘How are your Alfa Laval heat exchangers working out?’” Mark Lauderbaugh of Trident Process, the local Alfa Laval representative agrees, “It’s an open industry.” Meetings, trade shows, and informal get-togethers all bring producers and production facilities closer together, and “we’re always talking about the industry,” nods Kor.

The plus in Corn Plus

Success has brought growth to Corn Plus “We went through an expansion in September of 2001,” Kor explains. That was when Corn Plus also did something about the problems they had been having with flow issues, plugging, and downtime in their original heat exchangers. They contacted Alfa Laval and bought three wide gap plate heat exchangers for fermenter cooling. “The heat transfer was good, and the investment more than paid for itself in downtime.” So Kor started looking at the centrifuge side and by the summer of 2003 the new decanter centrifuges used to make the stillage into animal feed started up. In addition, Corn Plus acquired an AlfaVap for evaporation of the decanter centrate, and one AlfaCond plate condenser. Another plate evaporator is going in later this year. And there’s more change in store.

“We’re in the middle of an energy crisis,” notes Kor. “The cost of natural gas is extremely high. We’re planning to put in a fluidized bed incinerator that will burn biomass products to create steam to run the plant.” It’s expected that this process will replace 75% of Corn Plus’ natural gas usage and will be online by April of 2005. “That will also take care of our environmental issues that we have with the pollution control agency in regard to our drier stack gases. We’re going to be the first ones on the block to do that, and we’re pretty excited about it,” Kor says.

From cornfield to fuel tank

There are two commonly used processes for creating ethanol; wet milling and dry milling. “Corn Plus was the first dry mill ethanol plant in Minnesota,” notes Keith Kor proudly. Corn is delivered to the plant by Corn Plus cooperative farmers, where it is ground into meal. The meal is slurried with water to form a mash, with enzymes to convert the starch to sugar

Alfa Laval plate heat exchangers at Corn Plus.The mash is processed in a high-temperature cooker to reduce bacteria levels before fermentation begins. It is then cooled and transferred to fermenters where yeast is added and the conversion of sugar to ethanol and carbon dioxide begins. Alfa Laval supplies the heat exchangers used to heat and cool the cornmeal-enzyme mixture. The fermentation process takes forty to fifty hours to complete, during which time the mash is agitated and kept cool, enabling the yeast to work. After fermentation, the resulting beer is transferred to distillation columns where the ethanol is separated from the remaining stillage.

The stillage goes through an Alfa Laval decanter that dewaters the residual corn solids (primarily protein and fibre) to form a cake. The water removed by the decanter still contains soluble solids and that stream is sent to an evaporator where it is concentrated into thick syrup. The decanter cake and evaporator syrup are combined and sent to a dryer to produce a high-quality livestock feed. Indeed, these so called by-products are essential in economic terms: when asked how much the by-products contribute to the profit, Keith Kor laughs. “The by-product is the profit!” he says.

The CO2 released during fermentation is captured and piped directly to Dixie Carbonics, a company located adjacent to Corn Plus, where it is used to manufacture dry ice and liquid CO2 for beverages.

The future is here

Turn into Corn Plus’s driveway, and the first thing you’ll see are the fuel pumps: 90% petrol, 10 % ethanol in one, 15% petrol, 85% ethanol in another. No one loses sight of the end product, even as the corn trucks trundle past the pumps on their way to deliver their loads of corn to the grinders. At Corn Plus, it is clear that the future is already here. “There are a lot of vehicles that are accepting ethanol,” says Gary Lium, maintenance manager at the plant.

“They’re called flexible fuel vehicles – FFVs. You see them more and more these days.” Especially here in the Midwest, home to nearly all of the ethanol production facilities in the United States. FFVs are now available in nearly every vehicle category. “We’re extremely confident about the future,” affirms Keith Kor. At least twenty of the co-op members and employees are driving flexible fuel vehicles; Keith Kor’s own truck takes E-85. So it’s fair to say that, for them, the future is today’s reality.

Education is key

Corn Plus, like all other U.S. ethanol producers, faces some serious challenges moving forward. The biggest issue, according to Keith Kor, is that of education: “We don’t have enough qualified people to run the plants,” he points out. “There are now two schools here in the Midwest that are providing training for the industry. It’s a two-year programme, and it’s growing. And we still need more!”

Educating the public is essential. “It’s the fastest-growing industry in the world, and that usually surprises people,” says Alfa Laval’s John Robertson. “You have to wonder why.” Keith Kor agrees. “I think the biggest challenge today is to educate the public on the benefits of ethanol,” he says. There is a great deal of misinformation about. Kor cites a recent article in a national newspaper that was “just wrong. But it’s very political. Here we have something that’s renewable, good for the environment, and grown here – it’s not imported.”

Perhaps that is the most attractive aspect of ethanol. Locally grown biomass (grapes in France, sugar cane in Brazil, cereals and corn in China, etc.) is producing ethanol for local use, reducing dependency on foreign imports, and helping countries solve their own fuel challenges. And that’s something that is good for everyone.

Alfa Laval / Corn Plus cooperation

Alfa Laval sold a package of equipment to the Corn Plus distillery at the end of 2002; two NX 944 decanter centrifuges for stillage dewatering, three MA 30 wide gap plate heat exchangers for fermenter cooling, one AlfaVap EC 600 for evaporation of thin stillage and one AlfaCond plate condenser.

The plant came online using heat exchangers from another supplier but there were problems with flow and plugging and with a general lack of reliability. Alfa Laval then sold Corn Plus its fermenter coolers that led to more equipment purchases. “We didn’t look back after that,” says Keith Kor, general manager of Corn Plus. “The reliability and the productivity were exceptional.”

The distillation process at Corn Plus initially involved four 30-year-old decanter centrifuges that had become costly to maintain, with high power consumption and poor separation. The cake was too wet (sending too much moisture to the dryer) and the centrate was too dirty (reducing evaporator effectiveness).

Corn Plus is very pleased with the NX machines, which replaced two of the old decanters. The new decanters are efficient, easy to maintain and control and they have low noise and vibration levels.

“We couldn’t be happier about the relationship we have with Alfa Laval,” says Keith Kor. “All the maintenance is done onsite, which reduces downtime, and Alfa Laval trains our people. The proof of the relationship is in plans for the future. We’ve ordered a centrifuge that’s going to be delivered in July, and my goal is to have yet another new centrifuge by the end of the year.”

Dell Hummel, Alfa Laval adds Corn Plus has become a real showcase for all of our distillery equipment. That alone speaks volumes about the relationship we share.”