Converting plastics into oil.

In the future, instead of incinerators or landfills, waste plastics may be carried to "converters" for quick, efficient, and environmentally friendly transformation to commercially usable oil, according to M. Mehdi Taghiei, senior research associate, Institute for Mining and Minerals Research, University of Kentucky. "We have successfully converted plastics of many kinds [polyethylene, polyethylene terephthalate, as well as actual plastic wastes from such consumer items as milk jugs and soft drink bottles] into oil. Additionally, we have been successful in coliquefying coal with waste plastics."

By turning plastics into oil, scientists hope to be able make a big dent in the recycling problem. Plastics constitute up to 40% of the volume of landfills. Taghiel estimates that, at the current annual rate of plastic waste disposal in the U.S., "over 80,000,000 barrels of oil could be produced. The oil produced from plastic liquefication is similar to imported crude oil, but somewhat lighter and easier to refine and use as a transportation oil. "Unlike crude, the oil from plastics is free from sulfur, and therefore more environmentally benign.

In the process, plastics--either alone or mixed with coal--are combined with tetralin (a hydrogen feedstock) and a zeolite-based catalyst in a reactor. The contents then are heated at 400-450[degrees] C for up to 60 minutes a pressure of...