Thermal Processing of Toxic Flame-Retarded Polymers Using a Waste Fluidized Catalytic Cracker (FCC) Catalyst

Abstract

Waste electrical and electronic equipment (WEEE) plastics are particularly problematic to recycle because they contain a variety of brominated flame retardants, some of which are extremely toxic. Pyrolysis has been proposed as a viable processing route for toxic WEEE plastics, but it has been found that the volatile pyrolysis products contain toxic brominated compounds. In this work, we have built on previous work where we reported that zeolite catalysts were capable of destroying toxic organobromines during pyrolysis (Hall, W. J.; Williams, P. T. J. Anal. Appl. Pyrolysis 2008, 81, 139—147). We have investigated the pyrolysis of brominated high-impact polystyrene and acrylonitrile—butadiene—styrene in the presence of a waste fluidized catalytic cracker (FCC) catalyst. It is reported that, unlike Y-zeolite, the FCC catalyst did not completely destroy the organobromine compounds; however, the catalyst did lower the yield of bromine found in the liquid pyrolysis products by a mechanism that is as yet unclear. The waste FCC catalyst did not greatly alter the composition of the nonbrominated pyrolysis products, and valuable single-ring aromatics were present in the pyrolysis oil.