Distribution of Coplanar PCB Isomers in Pyrolysis Products of Polymer Waste

摘要

Coplanar PCB is the chlorinated phenyl containing up to two substituted chlorines at the ortho- location, which includes 14 different isomers. Recently the coplanar PCB is considered to be one of dioxin equivalent toxic compounds with adding into dioxin concentration in TEQ by WHO. Therefore generation mechanism and distribution characteristics of coplanar PCB in thermal processes of waste are needed to investigate as PCDDs/PCDFs have been focused previously. In this research a simulated polymer waste was pyrolyzed to produce gas, oil and char at 600℃ with and without PVC, oxygen and catalyst. And coplanar PCB concentrations of the products (gas, oil and char) were analyzed to observe their distribution with WHO toxic equivalent factor. It was confirmed that coplanar PCB was generated during the pyrolysis reaction with existence of PVC. Without PVC, coplanar PCB was not found in pyrolysis products even with and without oxygen. The total amount of coplanar PCB generated was compared in products at the conditions of with and without PVC, oxygen and catalyst. Oxygen was fed with air ratio of 0.5 for oxygen effect experiment. In char the concentration of coplanar PCB was not much dependent on oxygen existence but catalyst. However oxygen is more effective factor for coplanar PCB formation in gas and oil produced from pyrolysis of polymer waste.