A Tale of Two Corn Kernels

From Field to Fuel and Beyond A Tale of Two Corn Kernels: From Field to Fuel and Beyond

By Haley Banwart

In Iowa, corn is king, and that’s no accident. With its fertile soil and favorable growing conditions, the state consistently leads the nation in corn production, outpacing entire countries in total output.

Iowa farmers harvest an estimated 12.9 million acres of corn each year, producing around 2.4 billion bushels. But corn’s impact extends far beyond the field. It plays a pivotal role in various industries, serving as a key ingredient found in nearly 4,000 everyday items like crayons, toothpaste, tires and beer.

However, corn’s versatility doesn't end there. Follow the journey of two corn kernels: one redefining sustainability through innovative bioplastics, the other fueling the future as ethanol.

PLA: A Renewable Alternative to Plastic

Iowa’s top crop is shaping the future of bioplastics through polylactic acid (PLA). As an industrially compostable material, PLA offers an eco-friendly alternative to petroleum-based plastics and is used in everyday items like food packaging, water bottles and service ware.

“Unlike the vast majority of plastics, which are still made from petroleum, PLA is a plant-based material made right here in America, helping to reduce dependence on foreign oil and energy,” explains Alex Buck, Ph.D., PMP, director of industrial innovation for Iowa Corn. “It serves as a ‘compost-to-compost’ vehicle for food, meaning both the packaging and the food it carries can return to the soil.”

PLA is a homegrown product derived from one of our most abundant agricultural commodities, and it doesn’t break down into harmful microplastics. This makes it a sustainable alternative for the future.

Alex Buck, Ph.D. PMP, director of industrial innovation for Iowa Corn

Water Bottle: PLA Production

Harvesting In the fall, mature corn is harvested using combines that separate the kernels from the cobs. 

Transportation The collected kernels are transported to a corn wet-milling facility. 

Steeping The corn kernels are steeped in acidic water to soften them and begin the separation process to extract starch, the base material for corn bioplastic. The corn oil, fiber and protein are separated. This corn oil is food grade, and the protein and fiber are sold separately (not combined) as animal feed. 

Liquefaction and Saccharification Corn starch undergoes processing to extract the starch. The base material for bioplastics is mixed with enzymes to convert it to simple sugar (glucose), also called dextrose. 

Fermentation A bacterium (lactobacillus) is used to convert glucose into lactic acid, the basic building block for polylactic acid. This is the same lactic acid your body produces. 

Conversion Lactic acid monomers (bonding molecules) are converted into lactic acid dimers (the result of combined monomers), called lactide. This ensures the future PLA will have the desired properties.

DistillationThe lactide is distilled for purification. 

Polymerization The lactide undergoes polymerization to create polylactic acid (PLA), an industrially compostable plastic alternative. 

Bottle Manufacturing PLA pellets are melted and molded into water bottle preforms using specialized equipment. Then the preforms are molded into the desired shape of a bottle.  

Finishing Touches The bottles are trimmed, sterilized and prepared for packaging. 

Distribution Eco-conscious brands package and distribute the bottles to stores and consumers. 

End of Life After use, these bottles can be industrially composted, breaking down into natural elements and reducing waste in landfills. PLA is especially beneficial in food packaging, plates and cutlery since it helps divert food waste into compost streams.  

Ethanol: A Homegrown Fuel

Beyond its traditional uses, corn has become a critical component in the renewable energy sector, particularly in ethanol production. Iowa leads the nation in ethanol production, with 62 percent (1.6 billion bushels) of the corn grown in Iowa going to create nearly 30% of all American ethanol. 

“Iowa’s ethanol industry is a key demand driver for corn, keeping our agricultural economy strong," says Buck. “But ethanol production isn’t just about fuel. It also creates valuable co-products like dried distillers grains (DDGs), a high-protein feed source for livestock.”   One bushel of corn produces 17 pounds of DDGs as well as 2.8 gallons of ethanol.

Ethanol — Fuel Production

Harvesting Like its PLA-bound counterpart, this kernel is harvested and processed.

Transportation The collected kernels are transported to ethanol production facilities. 

Milling The corn undergoes milling at the plant, where it's ground into a fine powder.

Liquefaction and Saccharification The corn powder is mixed with water and enzymes, converting starches into fermentable sugars. 

Fermentation Yeast is added to the mixture, fermenting the sugars into ethanol and carbon dioxide over several days. 

Distillation The resulting “beer” is distilled to separate ethanol from residual solids and water. 

Dehydration and Processing Ethanol is dehydrated to achieve the desired purity level for fuel use, while the corn oil is separated from the protein and fiber to be sold for biodiesel. The leftover protein and fiber are sold for animal feed as distillers grains. 

Denaturing The purified ethanol is blended with gasoline or other approved products to create denatured ethanol, as required by law. This ensures it is used only for fuel. 

Distribution The purified ethanol is transported to blending facilities, where it's mixed with gasoline and distributed to fuel stations. 

Two Paths, One Mission

While their journeys differ, both kernels serve a shared purpose: leveraging Iowa’s corn to create products that contribute to a more sustainable world. Bioplastics like PLA address the mounting issue of plastic waste, while ethanol reduces emissions and fosters energy independence. Together, they demonstrate the boundless potential of corn as a resource.

“Iowa corn farmers care deeply about the environment because they always want to protect their number one investment — the land itself,” shares Buck. “They use sustainable practices like no-till farming, cover crops and fertilizer management to preserve soil health and water quality. At the same time, innovations like PLA and ethanol show how industries are working together to create sustainable solutions.”