By TUX TURKEL

MaineToday Media, Inc.

It's not apparent, but the plastic bottles of Noble Juice at Wal-Mart and local supermarkets are made from corn, not petroleum. So is the resin liner inside a Green Mountain Coffee Roasters takeout cup, and the plastic iced coffee cups used by Coffee By Design in Portland.

This bioplastic comes from a facility in Nebraska owned by NatureWorks LLC, a subsidiary of international food and farming giant Cargill. It's the country's first manufacturer to harvest the starch stored in plant sugars and create a clear plastic, called polylactic acid, or PLA.

What would it take to build a similar facility in Maine that would make PLA from potatoes?

That question will be a prime focus during a conference on Oct. 26 at the University of Southern Maine in Portland. Billed as a summit on green chemistry and bio-based manufacturing in Maine, the session will bring together researchers, farmers and companies interested in developing this technology here.

"It's the beginning of a revolution, because we know we have to replace petroleum," said Michael Belliveau, executive director of the Environmental Health Policy Center and an organizer of the conference.

Maine, with its forest and agricultural resources, may be well-positioned to participate in this revolution. Making plastic from potatoes could be an early step, Belliveau said, because the technology already exists. What remains unanswered is whether it makes economic sense to build a commercial-scale project here in the near future, and whether it can attract the needed public and private money.

Making plastic from potatoes is just one avenue of exploration in Maine's quest to be a player in bioenergy.

A group based in Rumford, the Fractionation Development Center, is trying to attract money and research to build a $45 million biorefinery to convert wood biomass into oil and electricity. Organizers have been making presentations in possible host communities, including Millinocket.

The University of Maine last year won a $6.9 million National Science Foundation grant to help create an integrated forest biorefinery. The technology would extract chemicals from wood chips at pulp and lumber mills and use them to make fuel ethanol, plastic or other products now derived from petroleum.

Some of the participants in this effort are wrapping up a two-day conference today in South Portland. The event was held to link university researchers and small businesses interested in environmental and alternative energy issues.

The potatoes-to-plastic effort got a boost last summer, following a preliminary study by the Margaret Chase Smith Policy Center at the University of Maine. The work was done for Interface Fabric Inc., a commercial textile manufacturer with factories in Guilford and Dover-Foxcroft. Interface has a strong commitment to sustainable manufacturing, currently making products from recycled plastic, reclaimed wool and bio-based fibers. Interface wants to know whether it makes economic sense to use Maine potatoes as a source of PLA for bio-based fabrics. The company figures it needs 13 million pounds of PLA a year.

The study found that the cost of processing potatoes for PLA would be similar to using corn. The feedstock could come soley from waste and below-market-grade potatoes, the study determined.

But because this plant would be the first to make PLA from potato starch, many questions remain unanswered. It's unclear how the waste potatoes would be collected. It's also possible that certain varieties can be grown using fewer pesticides and fertilizer, making the venture more profitable for growers and better for the environment. And while a plant would likely be located near the potato fields of Aroostook County, placing it next to a factory that can use waste heat or produce electricity might improve the economics.

"We really feel this research is promising, but you've got to do the work," said Jonathan Rubin, an environmental economist at the Smith center.

Interface and the university now are trying to win a $1 million federal grant to look at these and other issues. The partners are awaiting word on a pre-application request from the U.S. Department of Agriculture.

If the economics line up and the project can attract investors, Rubin and others estimate a potatoes-to-plastic plant could be built in Maine within five years. Underlying that assumption is petroleum prices staying high.

"Oil at $80 a barrel is a lot of incentive," Rubin said.

Besides Interface, other companies with Maine ties may be interested in bioplastics for their products. The trick will be bringing cost and performance in line with petroleum-based plastic or other alternatives.

Tom's of Maine, the natural care products company, tested a PLA-based bottle for mouthwash. It leaked, according to Chris Chappell, the company's consumer care director.

Tom's experience underscores a challenge for bio-based plastics. Cornstarch-based plastic containers and flatware are available on the market, for instance, but they don't hold up at temperatures above 135 degrees.

Tom's wants to find a bioplastic that works for its deodorants, liquid soaps and floss containers. The company already uses packaging that's highly recyclable, but it is interested enough in the potential of Maine potatoes to co-sponsor the green chemistry conference.

"We want to be responsible with our packaging," Chappell said. "We've done what we can, but as the technology evolves, we want to do more."

Other Maine companies that could help support a local bioplastics industry are Sagoma Technologies of Biddeford, which makes CD cases and other items, and Rynel Inc. of Wiscasset, which makes polyurethane foam products for medical and personal care markets. Nestle Waters North America, which sells the Poland Spring brand, also is exploring bio-based plastic for the 3 billion bottles it fills each year in Maine, Belliveau said.

Although potato production and PLA processing is centered in northern Maine, the green chemistry conference is being held in Portland, Belliveau said, to reach out to southern Maine's business community. Any project, he said, will need political support and venture capital to get off the ground.

Staff Writer Tux Turkel can be contacted at 791-6462 or at: tturkel@pressherald.com