Growth of bioplastics concerns recyclers
by Brian R. Hook 
While bioplastics, made from plants such as corn, are being
promoted as a green alternative to petroleum-based plastics, recyclers worry
that mixing even the smallest amount with traditional oil-based plastics may
cause severe contamination issues.
Bioplastic sales are growing, said Mary Rosenthal, a corporate
communications leader at NatureWorks LLC, one of the largest producers of bioplastics.
The Minnetonka, Minnesota-headquartered company has a production facility in
Blair, Nebraska.
“Since commercialization in late 2003, we have seen triple and double-digit
growth rates, year over year,” Rosenthal said. She would not reveal volume
numbers for the 50/50 joint venture between Minneapolis-based Cargill Inc.
and Teijin of Japan. However, she said the current capacity of its Blair facility
is 300 million pounds.
“We are now in a phase of expanding our plant capacity,” Rosenthal
said.
NatureWorks produces a biopolymer made from natural plant
sugars, which are fermented and made into lactic acid. The material is transformed
into a monomer and polymerized into small plastic pellets. By replacing petroleum
with a plant-based feedstock, NatureWorks uses up to 67 percent less fossil
fuels to produce its plastics.
“NatureWorks’ biopolymer provides all the performance characteristics
of traditional polymers, without being made from oil,” Rosenthal said,
noting that it is made from 100 percent renewable resources, acquired through
traditional feedstocks.
NatureWorks biopolymer, marketed under the Ingeo brand, is
used to create a variety of different end applications, including bio-based
packaging, fibers, durables, service-wear, apparel, hygiene products, and products
for the home and garden.
More than 45,000 retail stores are selling products made from
NatureWorks biopolymer. Wal-Mart, for example, has more than 14 applications
in its product aisle.
NatureWorks’ goal is to keep the biopolymer, regardless of form, out
of the landfill and recycled into the same use or higher uses if possible.
Where food-composting infrastructure exists, NatureWorks recommends composting
bioplastics. Or if sorted, NatureWorks suggests chemical hydrolysis to turn
the lactic acid back into resin.
“We are in a journey with the recycling community, working at ways and
means for identification, collection and sorting,” Rosenthal said. “We
are committed to working responsibly on this journey and work with the recycling
community to do so.”
Many recyclers are concerned, however, because the industry
is starved for resin material. “Plastic recyclers are business people. If they can obtain
enough consistent plastic, they will try to recycle it to high value end uses,” said
David Cornell, technical director at the Association of Postconsumer Plastic
Recyclers in Washington D.C.
“Materials that degrade the consistency or quality of the feed are not
welcome. We know that small amounts, as little as 0.1 percent, of incompatible
plastics can ruin PET (polyethylene terephthalate resin) for reuse. When bioplastics
are used for the same applications as PET, such as bottles, the bioplastics
may become contaminants.”
Cornell said that he expects more bioplastic products to
enter the market. He estimates that the amount of bioplastics produced for
the market is currently less than 200 million pounds, with most used in packaging.
In contrast, the total for all thermoplastics used annually throughout the
United States is currently over 100 billion pounds. 
“Separating the contaminants is expensive. The difficulty for recycling
bioplastics is that the critical mass needed to create the infrastructure is
not there,” Cornell said.
“We estimate that over 400 million pounds of consistent material in readily
recognizable form must be in the marketplace annually to justify investment
in recycling.”
Other bioplastic producers include Cambridge, Massachusetts-based
Metabolix Inc, which formed Telles, a 50-50 joint venture with Decatur-Illinois-based
Archer Daniels Midland Co. to commercialize the production of Mirel bioplastics.
The bioplastics are made by microbial fermentation of sugars from corn or sugar
cane.
Tamara Nameroff, acting director of the American Chemical
Society Green Chemistry Institute in Washington D.C., said she expects more
bioplastics production.
“The growth is increasing as the feedstocks for bioplastics become cost-competitive
due to the rising price of oil,” Nameroff said. “If a policy decision
is made to reduce greenhouse gas emissions, that would also be an additional
signal to the market.”
Some of the drawbacks to bioplastics are that it takes pesticides,
fertilizers and water to grow bio-based feedstock on a commercial scale for
bioplastics, Nameroff said. Plus, some of the same sources for bioplastics
are also used for food production.
“The biggest benefit will come from bio-based polymers that are made
from agricultural waste materials that don’t have other current uses,” Nameroff
said.
Skaidra Smith-Heisters, a policy analyst with the Reason
Foundation think tank in Los Angeles, said the largest driver of consumption
of bioplastics, is government mandates, for example, bio-based procurement
programs at federal and state levels.
“These programs seek to subsidize domestic farm production, particularly
corn and soybeans and/or subsidize research and development of cost-competitive
biodegradable technologies,” she said.
She said that as these programs and restrictions on plastics
expand, the use of bioplastics is also expected to grow, including biodegradables.
While not all bioplastics are biodegradable, most biodegradables are bioplastics.
“The great costs incurred by mandating use of biodegradable plastics
(for example, biodegradable plastic grocery bags in San Francisco) are out
of proportion with the benefits of reducing the relatively small amount of
conventional plastic that unintentionally escapes waste disposal and recycling
paths,” Smith-Heisters said.
“Meanwhile, biodegradable plastics are a serious problem when and where
they enter either conventional plastic recycling or green-waste composting
streams. This problem will grow as biodegradable plastics proliferate in residential
waste. Few waste haulers and landfills are able to accommodate the composting
of biodegradable plastics.” |
