Pyrolysis is a process of thermal degradation of a material in the absence of oxygen. Plastic is continuously treated in a cylindrical chamber and the pyrolytic gases condensed in a specially-designed condenser system to yield a hydrocarbondistillate comprising straight and branched chain aliphatics, cyclic aliphatics and aromatic hydrocarbons. The resulting mixture is essentially equivalent to petroleum distillate. The plastic is pyrolised at 370ºC-420ºC and the pyrolysis gases are condensed and liquid separated using fractional distillation to produce the liquid fuel products.
The essential steps in the pyrolysis of plastics involve:
evenly heating the plastic to a narrow temperature range without excessive temperature variations
purging oxygen from pyrolysis chamber,
managing the carbonaceous char by-product before it acts as a thermal insulator and lowers the heat transfer to the plastic
careful condensation and fractionation of the pyrolysis vapors to produce distillate of good quality and consistency