Discarded plastic bags could end up in your car's gas tank as fuel

Discarded shopping bags and other plastic waste can be turned into liquid fuel for vehicles using a relatively low-temperature process, Indian researchers say. Writing in the International Journal of Environment and Waste Management, the scientists describe a commercially viable technology for efficiently rendering low-density polyethylene, a common polymer, into a liquid fuel. With most plastics being made from petrochemicals, this solution to plastic recycling brings the life cycle full circle allowing a second use as an oil substitute, they said. In the recycling process, plastic waste is heated to 750 to 900 degrees F over a kaolin catalyst, causing the plastic's long chain polymer chains to break apart in a process known as thermo-catalytic degradation. This releases large quantities of much smaller, carbon-rich molecules like paraffins and olefins, yielding a liquid fuel very similar chemically to conventional petrochemical fuels, the researchers said. Every pound of waste plastic can produce about 10 ounces of liquid fuel in the process, they said. If implemented on a large enough scale, they suggested, the technique could reduce pressures on landfills while offering an alternate source of fuel in a world of dwindling oil supplies.