Sioux Falls-based Poet LLC already uses a process called BPX, which converts starch to sugar and then ferments it to ethanol without the use of heat or cooking. Poet uses the method in 20 of its 22 ethanol plants and estimates it can get 3 gallons of ethanol from each bushel of corn compared with an industry standard of 2.7 gallons per bushel.
Poet is working with Jay-lin Jane, a carbohydrate chemist and professor in Iowa State's food science and human nutrition department, to look at differences between starches in various varieties of corn.
The goal is to identify which lines of corn starches are more easily broken down into glucose by the enzyme used for conversion. The glucose is then fermented into ethanol and carbon dioxide.
"When starch is in the corn plant, it's sometimes difficult to break down," said Mark Stowers, Poet's vice president of research and development. "So what we're trying to understand is how the starch is structured in various corn plants so that we can do a better job and more efficiently break the starch down into the sugars for the ethanol process."
Jane said some starches are loosely packed in the granule and can be easily broken into glucose. Others, especially those with different crystalline structures, prove much more difficult.
"Certain corn lines are more easily susceptible to enzyme conversion," she said.
Jane said she's about four months into the two-year project, which is co-funded by Poet and a state economic development fund. Poet said it's contributing $284,000 to the project over two years and the Grow Iowa Values Fund is contributing $149,233.
"We are generating more exciting results every day," Jane said Wednesday.
Stowers said the BPX process helps the company reduce energy costs, increase ethanol yields, decrease plant emissions and improve the nutrient quality of its distillers grains, an ethanol byproduct used as cattle feed.
Poet officials hope the research collaboration will improve its per-bushel ethanol yield.
"I think that it's a good university-industry partnership to solve an important question, and that is how much more ethanol can we get out of an acre of corn," Stowers said. "And that has tremendous positive land implications."
In a separate project, Poet is working with growers and farm equipment manufacturers to develop ways to harvest, store and transport cobs that could one day join kernels as an alternative fuel source. Poet plans to expand its plant in Emmetsburg, Iowa, to produce 125 million gallons of ethanol per year — with 25 percent coming from corn cobs and fiber.
Poet is the largest U.S. ethanol producer, with 22 plants that can pump out 1.2 billion gallons of the alternative fuel. Additional biorefineries under construction or development will eventually add 327 million gallons of capacity.
Nationally there are a total of 142 ethanol plants, with another 58 under construction, according to the Renewable Fuels Association.