Zein technology to go commercial at Illinois ethanol plant

By Kris Bevill | March 23, 2011

Illinois-based technology developer Prairie Gold Inc. and GTL Resources USA Inc. are collaborating to produce zein protein at a commercial-scale plant, to be constructed near Illinois River Energy’s 110 MMgy plant at Rochelle, Ill. Illinois River Energy is a subsidiary of GTL Resources.

“This unique technology has the potential to significantly change the way we think about ethanol production in that instead of just producing ethanol and distillers dried grains (DDGs), we are becoming a biorefinery capable of producing several food, industrial and chemical products,” Rich Ruebe, CEO of GTL and Illinois River Energy, said.

Prairie Gold and GTL have been working together on the project since 2009 when they constructed a 2,400-square-foot pilot plant at the Rochelle ethanol plant site. Philip Shane, president of Prairie Gold, said trials conducted at the pilot plant tested various extraction methods to determine the best method to pull zein from corn kernels under specific conditions. Engineers optimized the process and provided data to influence the selection of equipment to be used at the commercial facility. Zein samples from the pilot plant were also provided to customers for market development activities. Shane said a groundbreaking date has not yet been set for the commercial plant, but he is optimistic construction can begin by the end of the year.

Zein is a natural, corn-based polymer with a wide variety of uses in multiple industries. It can be used to produce biodegradable plastics, shellac and other hard coatings and also has many applications in the pharmaceutical and specialty chemicals industries. Demand for the product is growing, according to Shane, but quality and pricing have inhibited its ability to enter the market in high volumes.  “Most of the issues that come with the product have to do with color, flavor and odor,” he said. “That’s what make our product unique is that it’s a very pale yellow color and it’s pretty much odorless and tasteless, which is a big advantage.”

Poet LLC is the only other ethanol producer known to be working on zein production technology. Its trademarked product, known as Inviz, is produced from DDGs. Massachusetts-based Freeman Industries LLC is the one other U.S. company currently producing zein, according to Shane. It uses corn gluten meal to produce zein. Prairie Gold’s trademarked Amazein is produced from the corn kernel. Typical zein production begins by using ethanol to dissolve and extract the zein protein from the raw product which, in Prairie Gold’s technology is corn kernels. From there, Prairie Gold utilizes membranes to purify the zein protein. Shane said this method reduces energy costs and increases the purity of the zein. Corn and ethanol used in the process are then returned the ethanol plant for its use.

Shane said Prairie Gold’s process extracts one pound of zein per bushel of corn. Ethanol and corn are merely “borrowed” from the ethanol plant and operations at the ethanol facility are not affected. “We don’t hinder their process or mess with their starch,” he said. “If we did, they wouldn’t like us very well.”

The market price for zein is approximately $18 per pound, Shane said. By comparison, DDGs are currently selling for 6 cents to 8 cents per pound.  The zein plant to be constructed at Illinois River Energy could produce 40 million pounds of zein annually, he said, but declined to offer production cost details. While the selling price is attractive, Shane cautioned that the company is focused on producing zein at a rate that will maintain its status as a high-value product. “Our business model is to partner with ethanol plants,” he said. “We do not want to flood the market with the product, because of the many uses for it. You’re talking about something that goes into a very high value market to one that’s very low. We don’t want to overproduce where we’d have to sell into the pharmaceutical industry for a plastic [industry] price.”