A tire recycling company with what it describes as a revolutionary ``reverse polymerization'' process hopes to have a demonstration plant up and running by spring 2005, according to two of its founders.
Tires are only the beginning for development of the process, they added, with the technology already proven to transform plastics into oil and energy. Someday, they said, a version of the process could be used to extract spilled and wasted oil from tar sand and coal shale.
``The day may come when we would actually mine landfills,'' said David Allen, vice president of Carbon Recovery Corp. of Medford. ``The plastics are there, and they're not going anywhere.''
Frank Pringle, chief engineer for Carbon Recovery and inventor of reverse polymerization, said he got the idea for it as an eyewitness to the disastrous scrap tire fire in downtown Philadelphia on March 13, 1996. That blaze, deliberately set in the now-closed Philadelphia Tire Disposal Inc. site, caused an estimated $3 million in damage to an overpass of Interstate 95.
``I got out of my car and saw this tremendous white-black cloud billowing up,'' said Mr. Pringle, who ran his own publicly traded company, Creative Recycling, in the 1980s. On his way back to his research job at a glass company in Raleigh, N.C., Mr. Pringle picked up a tire from the side of the road and in Raleigh put it in the glass company's reactor.
``I got the tire to spark and gasify,'' he said, giving him in turn the spark to develop the new process.
Further experiments with an old Amana microwave at a workshop in Paoli, Pa., Mr. Pringle said, led him further down the path toward inventing reverse polymerization. In that process, according to Carbon Recovery's Web site, complex organic compounds are broken down into their components in microwave ovens in an environment that does not support combustion or oxidation.
Because the process takes place in a vacuum, it eliminates the danger of the tires' steel content causing a fire in reaction to microwaves. Mr. Allen said.
Tire chips of 6-inch x 6-inch enter the microwave oven through vacuum tubes, he said, and the hydrocarbon content of the tires turns to gas, leaving carbon black and waste steel.
The process takes place in relatively low temperatures-150 to 350 degrees Celsius-much lower than pyrolysis or incineration, Carbon Recovery said.
The combination of a vacuum, low temperatures and uniform heating of waste materials allows the breakdown of the materials into simple molecules, as well as a much higher degree of control than pyrolysis or incineration to allow optimum energy production, the company said.
Under reverse polymerization, the company said, a typical 20-pound scrap tire can be broken down into 7.5 pounds of carbon black, two pounds of steel and 10.5 pounds of hydrocarbons, divided into 60-percent gas and 40-percent oil.
Carbon black was ``the gold of the process'' when reverse polymerization was first developed. But both Mr. Pringle and Mr. Allen said Carbon Recovery's focus is turning much more toward oil and energy production, particularly after both men read a recent National Geographic article about efforts to recover lost oil from various sources.
``That article stated that one gallon of oil for every person in this country is landfilled every day,'' Mr. Pringle said. ``And it could all be brought back into use.''
``Reverse polymerization'' is not a new term in tire recycling, according to Michael Blumenthal, senior technical director for the Rubber Manufacturers Association. ``Several companies have used it,'' he said. ``And several groups-including the University of Akron-have done a lot of work incorporating microwave technology into tire recycling.
``But the main question is, `What does ``reverse polymerization'' mean?''' Mr. Blumenthal asked. ``I don't know what all the people who use the phrase mean by it. But if these particular people mean they break tires down into carbon black, oil and gas, then it's pyrolysis. So we'll just have to wait and see if they can succeed with it.''
Currently, Carbon Recovery is working on finding backers to invest $15 million into a pilot plant to transform tires and plastics into oil and gas, Messrs. Pringle and Allen said.
Also, the company has plans to go public by year-end. According to the Web site, it has been authorized to issue 5 million shares of preferred stock-the value of which will be determined by company directors-and 50 million shares of common stock.
Meanwhile, having figured out the technology for recycling tires and plastics, Messrs. Pringle and Allen are paying close attention to Canadian efforts to regain spilled oil from tar sand.
``Frank is done with (development work on) tires,'' Mr. Allen said. ``All that's necessary now for that is the financing. But tar sand is a unique problem, and that's what he's working on now.''