Catalytic degradation of plastic waste into petrochemicals using Ga-ZSM-5

Catalytic degradation of polyolefin has been carried out using Ga-ZSM-5 in a pilot plant (10 kg/h), with continuous feeding of polyolefin pellets from industrial plastic waste (IPW) and pellets of plastic waste as stipulated in the Containers and Packaging Recycling Law (RLW). As regards the product resulting from the degradation of IPW pellets, liquid compounds accounted for more than 50%. More than 80% of the liquid consisted of aromatics, with more than 90% being benzene, toluene, o-xylene, m-xylene, and p-xylene (BTX). Hydrogen was produced at a level of 3%, this value corresponding to 60% of the total gas volume. It has been confirmed that degradation took place over a period of 460 h, with catalytic cracking under conditions of alternating degradation and regeneration. The liquid yield was more than half of the total product throughout the process of degradation. During degradation, the amount of BTX was observed to decrease slightly, while the amounts of other aromatics and liquids were seen to increase. With RLW pellets, aromatic yields, including those of BTX, decreased, while those of other liquids, gases, and residues increased beyond the values noted for IPW pellets. Due to the undesirable accumulation of residue on the inner walls of the kiln, the process could only be carried out for up to 170 h. (C) 2008 Elsevier Ltd. All rights reserved.