Pyrolysis of polystyrene waste in a fluidized-bed reactor to obtain styrene monomer and gasoline fraction

A specially designed laboratory fluidized-bed reactor apparatus was developed for the pyrolysis of polystyrene (PS) waste in the range 450-700 degrees C with nitrogen as the carrier gas and 20-40 mesh quartz sand as the fluidization medium, operating isothermally at atmospheric pressure. The yield of styrene monomer reached a maximum of 78.7 wt.% at a pyrolysis temperature of 600 degrees C. Some monoaromatics with boiling point lower than 200 degrees C could also be obtained as high-octane gasoline fraction. Styrene monomer with 99.6 wt.% purity was obtained after Vacuum distillation of the liquid products, which could be used as the raw material to produce high-quality PS. The attempt to increase the yields of styrene monomer and other monoaromatics by recycling the higher boiling point fraction to the reactor during pyrolysis is also discussed. (C) 2000 Elsevier Science B.V. All rights reserved.