About 75 miles away, at a facility near Blair, a constant rushing sound comes from long tubes that lead to gleaming steel silos. It sounds like kernels of corn, but it's actually millions of small plastic pellets. The pellets are plastic resin - the raw material for everything from food containers to carpet. For the last 10 years, a company called NatureWorks has used corn, instead of oil or natural gas, to make "bioplastic" near Blair. NatureWorks is partially owned by the agriculture corporation Cargill, and makes more bioplastic than any company in the world.
In Blair, NatureWorks uses the starch from corn to make lactic acid, which becomes the source for their bioplastic. Corn is easy to come by in Nebraska, but any starchy grain or vegetable could be the source for lactic acid. A new NatureWorks facility planned for Asia will use a different crop, possibly tapioca. Scientists have studied making plastic from lactic acid for decades. But only in last 20 years have Cargill researchers refined the process to the point where the bioplastic is useful for everyday products. They have also learned how to produce it on an industrial scale. Steve Bray is director of manufacturing at NatureWorks.
"The capacity of the plant is 300 million pounds of polymer per year," Bray said.
The bioplastic plant has not yet reached that capacity since starting up in 2001, but it's getting close.
"In the first three years of operation, we saw triple-digit growth," he said. "Almost every year it's been double-digit growth. When the worldwide economy fell in 2008 to 2009 that slowed us down, but even then we had growth. Now that the economy is coming back we're seeing very strong growth again."
NatureWorks production grew in the range of 20 to 30 percent in the last year, and that kind of growth is happening across the bioplastic industry. Kent Furst is an analyst with the market research firm, The Freedonia Group, based in Cleveland. He says even traditional plastic makers like DuPont and Dow are investing bioplastic.
"Whether you look at it in pounds or dollars, it's really growing very fast," Furst said. "We expect the industry to double in size in the next 3 or 4 years."
That kind of growth is impressive, but even after doubling in size bioplastics would still be less than 1 percent of the overall plastics market. Still, Furst said bioplastics are beating even the most optimistic forecasts. So why are companies using more bioplastic now? Furst said consumer interest is part of it. More people are shopping for sustainability. But it's the price of oil that's making it affordable for manufacturers to make the switch.
"With the price of oil and natural gas in the early part of the last decade being so low, you didn't see as much actual market interest in bioplastics," Furst said. "But as the price of oil and natural gas rose in the later part of the decade, I think that's when you saw how fast bioplastics could be competitive with conventional plastics on price."
Steve Bray at NatureWorks said as the price for a barrel of oil rises, bioplastic begins to look better by comparison.
"Certainly as you get to $110, $120 dollars we know that we're very competitive," Bray said. "Even today as prices have gone up we start to get more calls."
Click here for a summary report from The Freedonia Group on global demand for bioplastic
Click here for an infographic explaining how NatureWorks turns corn into bioplastic
But not all biplastics are made equal and that could start to cause some problems as they become more common. Paul Fowler, Executive Director of the Wisconsin Institute for Sustainable Technology, describes a growing bioplastics divide.
"Bioplastic could mean that the material is biodegradable, or it could mean that it's bio-based, or it could mean that it's both," Fowler said.
The differences in chemistry among bioplastics mean that some plant-based containers are biodegradable but hard to recycle. Others are easy to recycle but do not biodegrade. Even some oil-based plastics are called bioplastic because they claim to biodegrade.
Take, for instance, the Sun Chips bag made from NatureWorks bioplastic, called PLA for polylactic acid. What sets PLA apart is that it is completely biodegradable. In the right conditions, it would break down to water and carbon dioxide in a matter of weeks. But industrial composting facilities are more common in Europe than the U.S., and not many recyclers in the U.S. handle PLA plastic because it can contaminate the traditional recycling stream.
The Odwalla bottle, on the other hand, is made from Braskem bioplastic. It is HDPE plastic made from sugar, but after it has been used it is no different from an HDPE plastic bottle made from oil. It can be recycled almost anywhere in the country, but it does not biodegrade. So to compost or recycle? Fowler says there is room for both.
"If you consider the landscape for all the various products that are made from plastics, then there is a space for everyone within that landscape," Fowler said.
But he said it leaves consumers with a lot to learn. As more bioplastic shows up on grocery store shelves, sustainable-minded consumers will need to be prepared to choose from new shades of green.