Reactions of products from thermal degradation of PVC with nanoclusters of α-Fe2O3 (hematite)

Polyvinyl chloride (PVC) plastics constitute a large fraction of buildings, packaging and electronic devices, whereas, the annual emission electric arc furnace dust (EAFD) from steel manufacturing operations has recently peaked at nearly 6 Mt. Co-pyrolysis of PVC with EAFD currently represents a focal abatement technology for both categories of pollutants. However, despite of several experimental investigations; the mechanisms underlying interaction between EAFD and PVC remain largely speculative. Herein, we examine theoretically reactions of major products from thermal degradation of PVC with nanoclusters of iron (III) oxide, alpha-Fe2O3 (hematite) as a representative model for the various metal oxides in EAFD. The facile nature for the H-CI bond fission over hematite is in line with experimental findings, pointing out to formation of iron chlorides from pyrolysis of Fe2O3-PVC mixtures. Interaction of selected chlorinated C-1-C-3 cuts with the hematite structure preferentially proceeds via a dissociative adsorption pathway. Results from this study shall be instrumental to understand, on a precise molecular basis, fixation of halogens on transitional metal oxides; a viable thermal recycling approach for polymeric materials laden with halogenated constituents. (C) 2017 Elsevier B.V. All rights reserved.