Bioethanol is a clean-burning, renewable alternative to fossil fuel. It reduces consumer impact of greenhouse gas emissions, provides American jobs, and reduces dependence on foreign oil. POET is proud to produce bioethanol at 33 locations.

Bioethanol is an essential component of the 138-billion-gallon U.S. gasoline market.

When blended with gasoline, bioethanol increases octane ratings, reduces production cost by volume and facilitates compliance with emissions and fuel efficiency standards.

Bioethanol is by far the most widely produced renewable fuel in the United States today, with approximately 15.7 billion gallons produced in 2019. It is contained in 98% of the gasoline sold in the United States.

The majority of the bioethanol in the U.S. is made from corn, but it also can be produced from other feedstocks such as agricultural residue, grain sorghum, wheat, barley and potatoes. Bioethanol that is made from non-corn sources is called cellulosic bioethanol.

The POET dry mill process

MILLING: The feedstock passes through a hammer mill, which grinds it into a fine powder called flour.

FERMENTATION: Enzymes and water are added to convert starch into glucose, or simple sugars. Yeast is added to the mash to convert the sugars to bioethanol and carbon dioxide. The mash is continually agitated and cooled until the bioethanol concentration has been maximized.

DISTILLATION: The fermented mash, now called beer, contains about 20% alcohol plus all the non-fermentable solids from the corn and yeast cells. The mash is pumped to the continuous flow, multi-column distillation system where the bioethanol is removed from the solids and the water. The bioethanol leaves the top of the final column at about 95% concentration, and the residue mash, called stillage, is transferred from the base of the column to the co-product processing area.

DEHYDRATION: Alcohol is then dehydrated to 200 proof, or 100% alcohol, and the 200 proof alcohol is then pumped to a finished product tank. Prior to shipment, it is blended with approximately 2% denaturant, a gasoline-based product, to render the alcohol undrinkable and to prevent it from being taxed as a potable alcohol.

CO-PRODUCTS: After removing the bioethanol, we condense and dry the residue corn solids to produce distillers dried grains with solubles (DDGS), a nutritious animal feed. During the process of converting corn solids into DDGS, we can extract corn oil or proteins used to produce renewable industrial products.

CARBON DIOXIDE: Some of our plants also capture the carbon dioxide released from the yeast during fermentation, which we sell to a diverse customer base located throughout the Midwest for use in food processing, water treatment, fire suppression and agriculture.


Cellulosic bioethanol is bioethanol made from cellulose, a non-grain material/feedstock that provides the cellular structure for all plants. The end product – a clean-burning, high-octane fuel – is the same as bioethanol made from corn.

Cellulose, which provides the cellular structure for all plants, is the world's most abundant organic compound. POET has been researching and developing cellulosic bioethanol technology since 2001, performing bench-scale testing of our cellulosic technology at our research laboratory and more recently – through a partnership with Royal DSM of the Netherlands –commercial-scale cellulosic bioethanol production in Emmetsbrug, Iowa

POET-DSM Advanced Biofuels builds on the strengths of both companies to create a joint venture with a critical mission –- making cellulosic bioethanol competitive with grain bioethanol, the most competitive renewable liquid transportation fuel on the market today.
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