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Indexed by:Journal Papers

Date of Publication:2015-09-01

Journal:JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS

Included Journals:SCIE、EI

Volume:115

Page Number:362-369

ISSN No.:0165-2370

Key Words:Pyrolysis mechanism; Phenyl ether model compounds; Bond dissociation; Anisole; Phenyl ethyl ether; Benzyloxybenzene

Abstract:Anisole, phenyl ethyl ether (PEE) and benzyloxybenzene (BOB) with different oxygen substituents were selected as coal-related phenyl ether model compounds, and their pyrolysis behaviors at 500, 600 and 700 degrees C on a fixed-bed reactor were compared. The pyrolysis products were analyzed by gas chromatography-mass spectrometer (GC-MS) and gas chromatography (GC), and the bond dissociation energy (BDE) was calculated with density functional theory (OFT) methods at B3LYP/6-31G (d) level. The pyrolysis experimental results and theoretical calculations suggest that the C-aliphatic-O bond dissociation is an initial radical step of these model compounds. However, the substituents that connect to the oxygen atom make the model compounds have their own pyrolysis characteristics. The conjugate action generated from the two benzene rings in BOB weakens the BDE. And the existence of beta-H allows the phenyl ethers to form phenols through non-radical reaction at low temperature. In addition, the further reactions of phenoxy radicals affect the final composition of products. (C) 2015 Elsevier B.V. All rights reserved.