Chad Clark's Open Journal : 2007-07-30

1) Giant microwave turns plastic back to oil.

This is kind of interesting.  I have no idea how well it works or how much
energy it uses.

http://environment.newscientist.com/channel/earth/dn12141

  All that is needed, claims Global Resource Corporation (GRC), is a finely
  tuned microwave and hey presto!  a mix of materials that were made from
  oil can be reduced back to oil and combustible gas (and a few leftovers).
  
  Key to GRCs process is a machine that uses 1200 different frequencies
  within the microwave range, which act on specific hydrocarbon
  materials. As the material is zapped at the appropriate wavelength, part
  of the hydrocarbons that make up the plastic and rubber in the material
  are broken down into diesel oil and combustible gas.