FROM PLASTIC TO PETRO

Scientists are reporting that a new fuel source is in the bag—the plastic bag.

Researchers at the University of Illinois and the U.S. Department of Agriculture have been experimenting with ways to turn plastic shopping bags into fuels, including diesel, gasoline and natural gas. They say that the heat-based process they have used produces more energy than it consumes, and they've worked out in new detail the characteristics of the fuel produced from the bags. (click below to read more)


Plastic bags are light, strong and cheap, but they pose vexing environmental problems. A few of the bags are recycled (into composite lumber such as Trex, for example), but the great bulk of the billions used all over the world are thrown away. Discarded plastic shopping bags can end up clogging drainage systems, fouling the ocean and killing wildlife. Some cities and countries restrict their use.

Because the bags are made from petroleum, lots of laboratory and industrial effort has gone into finding ways to use them as fuel for combustion or to turn them back into oil. The latest research relies on a process called pyrolysis—heat applied in an oxygen-free chamber—to convert the bags into various crude-oil distillates. The scientists then analyzed the properties of those fuels. "Our work focuses on the utility of these oils and properties such as compatibility, stability, etc. in various blends," one of the scientists, Brajendra K. Sharma, said by email. "These details have not been previously available in the public domain."

The fuels produced by the scientists include a form of diesel that meets low-sulfur and other standards with the addition of an antioxidant chemical.

The researchers said that diesel derived from plastic bags blended well with conventional low-sulfur diesel up to a level of 30% from plastic, and it also appeared to be compatible with biofuels, an increasingly popular category.

"Production, Characterization and Fuel Properties of Alternative Diesel Fuel From Pyrolysis of Waste Plastic Grocery Bags," Brajendra K. Sharma, Bryan R. Moser, Karl E. Vermillion, Kenneth M. Doll and Nandakishore Rajagopalan, Fuel Processing Technology (online February)