'Green' chemists swap oil for renewable alternatives

Purifying and breaking down used petroleum-based plastics is costly. Instead, plastic recycling usually consists of taking a high-end product and producing a low-end one. "I want to be able to take a laptop computer and make another laptop computer, not a speed bump," Warner says. "The dream with our technology is to be able, at low cost, to recover the polymer in its originally useful form."

Optimal use of energy is a paramount concern.

"You have to look at the energy balance," Professor Coates says. "It's not just 'Did the stuff come from nature?' It's 'Well, if it came from nature, is it worth it?' If it takes a lot of energy, you might be better off just converting your fossil fuels" into plastic.

Energy efficiency also keeps costs low. "Folks in industry like green chemistry, because it helps them meet profit goals and economic competitiveness goals," Anastas says. "Nonhazardous nontoxic chemicals are going to be cheaper to manufacture, and add value to the industry."

Large-scale production of biorenewable plastics is already under way.

NatureWorks LLC, a subsidiary of food and agriculture giant Cargill, sells corn-based plastic to manufacturers of plastic containers, cutlery, and packaging. Chemical company Dupont's biorenewable Sorona plastic can substitute for polyester and other synthetic fabrics.

And last year, Wal-Mart announced its intention to use only biorenewable materials for its plastic packaging.

"To replace a commodity material, you have to get those economies of scale," says Ann Tucker of NatureWorks. Her company has been able to lower the price of its biorenewable packaging plastic from more than $1 a pound to about 63 cents. While the price of the equivalent petroleum-based plastic packaging currently can cost as little as 40 cents per pound, NatureWork's pricing is extremely competitive, says Frank Esposito of PlasticsNews. That's because petroleum-based plastics bear the cost of rising oil prices. Large orders, like those anticipated from Wal-Mart, should lower the cost of biorenewable plastic still further, he says.

Support is also trickling in from the political sector, as various state governors (including those of Maine, just last week, and New York earlier this year) mandate the development and use of nontoxic chemicals.

Interest in Washington cuts across party lines.

"The first perception is always that green chemists are tree- hugging hippies, until they realize that this is hard core beakers-and-flasks chemistry," Anastas says.

The last significant challenge, perhaps, is acceptance by an increasingly oil-conscious America.

"Using petroleum in materials is not as bad as burning it," Anastas says. "But we never want to use a finite resource at a greater pace than we can replace it."

Clothing: Synthetic clothes are essentially plastic, which, like soda bottles and storage bins, are made from petroleum-based polymers. That includes such fibers as polyester and nylons, synthetic substitutes for shoe leather, hard plastic buttons, and plastic zippers. Most clothing dyes are oil-based as well.

Detergents: The surfactants that enable many modern soaps and detergents to break up greasy stains are derived from petrochemicals.

Chocolate: Many chocolates maintain their appetizing look with the help of paraffin, an oil-based wax also used in candles. The paraffin helps molded chocolate hold its shape, and makes it look shiny. Food-grade paraffin is harmless, but nondigestible.

Soda bottles and other plastics: The polymers that form the building blocks of plastics are made from reconstituted monomers, traditionally derived from petroleum and natural-gas liquids.

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