Converting eco-unfriendly plastic into fuel.

• Author: Jean, Grace V.
• Position: INSIDE SCIENCE + TECHNOLOGY

* The next time someone sips from a plastic bottle or lugs home groceries in a plastic bag, consider this: Those products could either end up in a landfill for the next 1,000 years or be recycled into liquid fuel to power vehicles and homes.

Methods to convert waste plastics into hydrocarbon fuel have been in development for decades. But the associated costs to commercialize the technologies were prohibitive in previous years when crude oil was relatively inexpensive.

As costs for crude oil have risen, concerns about energy security and the environment are renewing efforts in plastics-to-fuel recycling processes. Scientists hope the technologies will soon provide the nation with cheaper, alternative fuels that can help reduce foreign oil dependency.

Natural State Research Inc., based in Stamford, Conn., has developed a technology that converts waste plastics into hydrocarbon liquid fuel through a thermal degradation process. First, the waste plastics are heated. They melt into a slurry that vaporizes when the temperature reaches between 370 degrees to 420 degrees Celsius. The vapor then travels through a tube and condenses into a liquid.

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"That liquid is fuel," says the technology's inventor, Moinuddin Sarker, who serves as the company's vice president of research and development. "It ignites and works in any internal combustion engine."

Following condensation, the liquid proceeds through a commercial purifier to produce the final product, called NSR fuel. Unlike conventional gasoline that contains sulfur, nitrogen and phosphor, the fuel is composed of only carbon and hydrogen because it is derived from plastic material--an already refined petroleum product.

In a laboratory-scale plant, the firm has demonstrated the ability to produce five gallons of fuel per day from a variety of plastics that do not have to be cleaned and sorted in advance. The technology will work for most types of plastics, which are made from combinations of elements and chemicals. These include ethylene, propylene and benzene that are derived from naphtha, which are flammable liquid mixtures of hydrocarbons obtained during petroleum refining processes, Sarker says.

A single plastic grocery bag can be converted into 10 milliliters of fuel. It takes 100 grocery bags to make a liter of fuel, which could power an automobile for five or six miles, Sarker says.

As the third largest manufacturing industry in the United States, plastics touch nearly...