Manataka American Indian Council






"Plastics" from Corn and Soy 

By Lori Leah Zack



Natural, or bio-plastics, are made from corn, soy or other renewable feedstocks and are being used in manufacturing textiles, food containers, and other products that traditionally utilize petroleum-based plastics. And it's biodegradable!!

The company Metabolix of Cambridge, Mass, was recently selected as a 2005 Presidential Green Chemistry Challenge Awards winner for developing a fermentation process to produce "natural plastics" from renewable feedstocks such as plant sugars or oils. Metabolix is set to start making its product on a large scale. It will join Cargill and Dupont--former Green Chemistry Award winners--as producers of "natural", or "bio-plastics."

A June 26, 2005 article in The Los Angeles Times, titled "To Replace Oil, U.S. Experts See Amber Waves of Plastic" explains what is meant by "bio-plastics". The following is an excerpt from that article:

In Blair, Nebraska, Cargill Inc. operates a factory where "corn (is) coming in at one end and plastic (is) coming out the other...a series of automated assembly lines turns raw corn kernels first into sugary syrup and then into white pellets that can be spun into silky fabric or molded into clear, tough plastic. The end products--which include T-shirts, forks, and coffins--look and feel and perform like traditional polyester and plastic made from a petroleum base. But the manufacturing process consumes 50% less fossil fuel, even after accounting for the fuel needed to plant and harvest the corn.

Chemists and engineers are racing to figure out how to use crops, weeds and even animal waste in place of the petroleum that fuels American manufacturing. The Energy Department is so enthusiastic that it is aiming to convert 25% of chemical manufacturing to an agricultural base by 2030.

Cargill is the first to commercialize the technology, producing 300,000 pounds of pellets a day--but its rivals are not far behind. DuPont Co., which invented polyester and nylon, has its own corn-based fabric in the works.

An Arkansas firm called Bio-Based Technologies just opened a factory that uses soy instead of petroleum to make polyurethane for use in seat cushions, shoe soles, and spray-foam insulation. The clothing firm Of the Earth, based in Oregon, sells T-shirts and yoga pants made from soy fiber.

University professors across the Midwest are turning their labs into miniature bio-factories, transforming soybean oil into mattresses and chicken feathers into golf tees--even, if all goes well, corn into cellphones. 'Anything you can make out of petroleum, I can make out of corn and soybeans,' said Larry Johnson, director of the Center for Crops Utilization Research at Iowa State University.

Skeptics question the economic viability of such projects. When Cargill launched its factory in 2002, its pellets were far more expensive than equivalent material made from oil. Wild Oats Market, an early customer, paid 50% more for takeout containers made from bio-plastic. But over the last two years, the Cargill plant has gotten more efficient--and oil prices have soared. The result: The 'corntainers' in the deli now cost Wild Oats 5% less than traditional plastic.

Other products made with the corn-based pellets are pricier. Depending on how they process the material, some manufacturers report that using Cargill's pellets raises their costs by as much as 25%. But a growing number in the United States and abroad is willing to pay that premium for a product perceived as environmentally friendly. (A Cargill spokesperson) tells her customers: 'We're using material that's renewable in 90 days instead of 90 million years.'

Converted into a biodegradable plastic, the pellets are molded into water bottles, portable CD players, auto parts and even coffins (sold in the Netherlands). The plastic is also used as packaging for Del Monte fresh-cut fruit and Newman's Own organic salads. Other companies are processing the pellets into fibers that can be used for T-shirts, carpets and super-soft diaper wipes. The Pacific Coast Feather Co. has.. a line of linens made from corn pellets. Faribault Mills is marketing a $100 wool-and-corn blanket that...(is) luxuriously soft.

The technology that turns corn into blankets--and so many other consumer goods--is actually decades old. In the 1920's and '30's, Henry Ford experimented with using crops, mostly soy, to make auto parts. But petroleum proved easier to convert into plastics; at the time, it also seemed a much more modern, forward-looking material. Plus, it was cheap. As late as 1970, oil cost about $3 a barrel--not much more than a bushel of corn. These days, corn still costs about $2 a bushel. It makes a good substitute for $60-a-barrel oil because, like petroleum, it contains carbon, the essential building block for plastic.

In theory, any carbon source would work in these new factories. Engineers say they'd like to replace corn one day with a crop that requires less fertilizer and pesticide, such as wild grass. They may even be able to use agricultural waste, such as cornstalks left in the field after harvesting. For now, though, raw kernels are the easiest to process.

Even if it takes off, bio-manufacturing will never wean the nation entirely from oil. Roughly 7% to 10% of the fossil fuel consumed in the U.S, is used to manufacture plastics and fibers...if corn replaced petroleum in every factory, the nation would cut oil consumption by hundreds of millions of barrels a year--but would still require billions more for heat, power, and fuel.

Given that limitation, some critics view all the hoopla as an agribusiness con, more about selling corn than saving the Earth...But other scientists maintain that the new technology offers genuine environmental benefits, beyond the reduction in fossil fuel use...(T)hey point to the huge problem of 'e-waste,' the 2.2 million tons of cell phones, computers, and other electronics dumped in landfills each year. If those products were made of bio-plastic, they could be composted. In the right conditions--warm and humid--they would degrade within months, dissolving into carbon dioxide and water."



Photo and caption from World Centric, a non-profit organization working to reduce economic injustice and environmental degradation through education, community networks & sustainable enterprises: 



Most corn and soy crops in the U.S. require heavy pesticide use, and some are also GMO-crops, or tainted with GMO genes.

The use of bio-plastics is only one part of addressing our dependence on oil and obviously, the looming issue of our growing need for non-oil-based heat, power, and fuel must be addressed in a comprehensive energy plan that includes the use of alternative and renewable energy sources.

I am most impressed with the possibility of bio-plastics being used to replace petroleum-based products that do not readily biodegrade: Imagine a compost pile made up of melting computer and cell phone housing! But would the earthworms "dig it"?


By Lori Leah Zack



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