Thermo-catalytic pyrolysis of polystyrene in the presence of zinc bulk catalysts

Zinc bulk catalysts (Zn, ZnO and ZnCl2) were used for the thermo-catalytic pyrolysis of EPSW and were found with high activity and selectivity of products. Thermo-catalytic pyrolysis was carried out using an efficient Pyrex batch reactor. Zn metal catalyst was found as the best catalyst amongst the zinc bulk catalysts for the cost effective pyrolysis of EPSW (expanded polystyrene waste). The yield of liquid products at 450 degrees C, 120 min heating time and 1:0.2 feed to catalyst ratio was 96.73 +/- 0.12 wt.% with 2.47 wt.% toluene, 1.16 wt.% ethylbenzene, 47.96 wt.% styrene monomer and 1.90 wt.% a-methylstyrene. The components of liquid products were separated by fractional distillation and found with further thermal pyrolysis in addition to cyclization and recombination reactions. During the fractional distillation, much product variations were observed. High molecular weight aromatic hydrocarbons decreased with the associated increase of low molecular weight aromatic hydrocarbons, particularly toluene and ethylbenzene. (C) 2014 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.