Catalytic pyrolysis of γ-irradiated polypropylene (PP) over HY-zeolite for enhancing the reactivity and the product selectivity

The effect of exposing polypropylene (PP) to gamma-irradiation prior to the catalytic pyrolysis over a HY-zeolite was investigated using a thermobalance and a semi-batch reactor. A significant increase in the rate of the catalytic pyrolysis was realized when PP was exposed to a small irradiation dose of 10 kGy. The high reactivity of the irradiated PP was conjugated with low yields of residue and coke in addition to enhanced selectivity for light distillate (C7-C10). Examining the effect of pyrolysis temperature revealed that the catalytic pyrolysis preferred high temperature among the investigated temperature range of 325-375 degreesC. A possible reaction mechanism was discussed based on the observed results and the reaction mechanisms reported in the literature. The results suggested the applicability of the proposed pyrolysis method for enhancing the catalytic conversion of plastic waste into useful hydrocarbons. (C) 2002 Elsevier Science Ltd. All rights reserved.