June 2003

Garbage Into Oil

How to turn garbage into fuel.

By Tracy Staedter

The recipe for making crude oil is relatively simple: combine the remains of ferns, jellyfish, and dinosaurs; cover with sediment; bury deep in the earth's crust; and apply pressure for millions of years-give or take an epoch. Or if you're pressed for time, run some turkey parts or used tires through the thermal process owned by Changing World Technologies of West Hempstead, NY. The system uses water, pressure, and heat to convert organic material into clean fuel gas, absorbent carbon (like that used in water filters),  minerals for fertilizer, and a crude oil that is chemically similar to a mixture of diesel fuel and gasoline; this oil can be sold to refineries and converted into fuel. The system produces no polluting emissions, and the only by-product is water.

In April 2003, the first commercial thermo-depolymerization plant opened in Carthage, MO. Every day, the plant handles 200 tons of unused turkey parts produced by ConAgra's Butterball turkey plant. Such waste is now typically reprocessed into animal feed, but this practice may not be allowed much longer in the United States: Britain has already outlawed it in the wake of hoof-and-mouth and mad-cow disease outbreaks traced to reconstituted animal feed.

The first stage of the thermal process has been around since the 1960s as a way to convert organic waste into hydrocarbon liquids. But the process has been inefficient, says Changing World chief technology officer Terry Adams, because it typically employs a single reactor both to heat the organic matter and to convert it into oil. That creates nonuniform heating, which breaks down molecules unevenly and results in a low-grade oil. Changing World uses two main reactors that heat and pressurize much more efficiently. And the system handles not only turkey offal but tires, plastics, sludge, municipal waste, paper, and livestock remains-expanding its potential for widespread use. "They have certainly produced the products they've claimed at a smaller scale," says MIT chemical engineer Jefferson Tester, who visited a pilot plant in Philadelphia and is intrigued by the larger-scale possibilities. Mother Nature can definitely transform the same products into usable fuel; you'd just have to wait a little longer.