How the US’s Most Abundant Crop Is Changing the Way Plastic Is Produced

Corn is at the heart of the US food system. As the country’s most
valuable crop, it generates about $75 billion in revenue every year. It’s also
the most widely planted, grown in all 48 contiguous states across about 90
million acres a year — an area roughly the size of Montana. In fact, the US
is the largest producer, consumer and exporter of corn in the world.

Of all that corn, however, only 1 percent of it is the sweet variety enjoyed at
the dinner table — the other 99 percent is field corn. As opposed to sweet corn,
which is a vegetable picked fresh in the summertime, field corn is a grain
harvested dry in the fall once the stalks and leaves turn brown and the kernels
harden on the cob; it is primarily used for feeding livestock (cattle, hogs and
chickens) and making fuel ethanol. The remainder is processed into products such
as starch, sweeteners, corn oil and beverages for human consumption.

After the grain is harvested in the fall, farmers are left with what is known as
corn stover —
the residue of stalks, leaves and bare cobs. It’s usually left on the field and
tilled back into soil when it’s ready to be re-seeded. However, with US corn
output rising (up a projected 11 percent this
year)
and grain yield topping 175 bushels per acre, many farmers have more corn stover
than they know what to do with.

What if there was a way to help corn farmers deal with their corn stover by
transforming it into something valuable?

New Energy Blue has developed a process for
turning corn stover into biobased ethylene. The company buys the agricultural
residue from farmers, careful to leave the cobs and bottom half of the stalks on
the field to replenish the soil. The top half is baled as feedstock for
converting into ethanol at New Energy Biomass Refinery operations now being
developed in the US’s heartland. Almost half of the ethanol produced is then
processed into plant-based ethylene — the hydrocarbon gas widely used to produce
plastic.

A perfect example of the circular economy in action, the corn stover is no
longer waste; instead, it becomes a valuable cash crop for which farmers can get
paid.

“There’s too much corn stover left in the field because of the amount of corn
being grown — and you need to remove it,” Thomas
Corle, CEO and Chairman of
New Energy Blue, told Sustainable Brands®. “So, our biomass refinery is a
good solution for the farmers. They get an additional revenue stream from corn
stover, which is especially welcome given the fluctuating price of corn grain.”

To effectively scale up processing, New Energy Blue has joined forces with
Dow — with which it signed a long-term supply
agreement in North America in May. Dow will purchase the biobased ethylene
and use it in recyclable applications across packaging, transportation and
footwear.

“Dow is supporting the first sustainable commercial production using this new
technology, because investing in innovation creates the best chance of finding
new solutions,” says Manav
Lahoti, Dow’s Global
Sustainability Director for Olefins, Aromatics & Alternatives. “Dow’s agreement
to purchase biobased ethylene enables New Energy Blue to scale its production
and ensures a value-added end market for diversion of agricultural residues.”

Corn plants absorb carbon dioxide as they grow; stover releases some of that
into the atmosphere as it decomposes on the field after harvest. By reusing the
otherwise wasted carbon, New Energy Blue’s innovation is also helping to cut
greenhouse gas emissions from the agricultural sector.

The collaboration will enable the design and development of a new processing
facility called New Energy
Freedom
in Mason City, Iowa. When it opens in 2025, it will process 275,000 tons of
corn stover every year, delivering commercial-scale quantities of
second-generation ethanol and clean lignin —a polymer that makes the cell walls
of plants rigid. Around half of the ethanol will be turned into biobased
ethylene feedstock for Dow products. It’s the perfect location given that Iowa,
along with Illinois, account for around a third of the corn grown in the US.

“Our biomass refinery has the ability to create bio-feedstock that can go into
products ranging from textiles and plastics to jet fuel,” Corle said. “Thanks to
this innovation, Dow is able to use a renewable carbon feedstock to manufacture
biobased plastics — which hugely reduces the overall carbon footprint of
products.”

This collaboration, Lahoti adds, “will redefine how Dow sources carbon-based
feedstocks — allowing us to expand our options for ethylene to include renewable
resources. We are excited by the possibility of plastics made from corn stover
to help our company achieve our Protect the Climate carbon goal and continue
supporting our Transform the Waste recycled-content
targets.”

Of the 90 million acres of corn planted in the US annually, only 150,000 acres
of corn stover is currently being collected — which means there is opportunity
to increase the role of corn stover as a feedstock for biobased plastic or other
renewable applications.

And since “biobased ethylene products are chemically identical to fossil-based
virgin products, they will be used across a number of different plastic
applications throughout our business enabling a lower carbon footprint for a
wide range of products,” Lahoti explained. “Potential applications include
lightweight materials used for transportation, cosmetics packaging, consumer
products like shoes, and food packaging that delivers fresh and reliable
products across the country.”

New Energy Blue’s technology not only benefits farmers and businesses — it also
ushers in a more sustainable future for US agriculture and exemplifies the power
of a circular economy.