Mechanisms of molecular product and persistent radical formation from the pyrolysis of hydroquinone
Document Type
Article
Publication Date
3-1-2008
Abstract
Hydroquinone is considered to be one of the major, potential molecular precursors for semiquinone-type radicals in the combustion of complex polymeric and oligomeric structures contained in biomass materials. Comprehensive product yield determinations from the high-temperature, gas-phase pyrolysis of hydroquinone in two operational modes (rich and lean hydrogen conditions) are reported at a reaction time of 2.0 s over a temperature range of 250-1000 °C. Below 500 °C, p-benzoquinone is the dominant product, while at temperatures above 650 °C other products including phenol, benzene, styrene, indene, naphthalene, biphenylene, phenylethyne, dibenzofuran and dibenzo-p-dioxin are formed. Hydrogen-rich conditions initially inhibit hydroquinone decomposition (below 500 °C) but promote product formation at higher temperatures. The decomposition process apparently proceeds via formation of a resonance stabilized p-semiquinone radical. Detailed mechanisms of formation of stable molecular species as well as stable radicals are proposed. © 2007 Elsevier Ltd. All rights reserved.
Publication Source (Journal or Book title)
Chemosphere
First Page
107
Last Page
113
Recommended Citation
Truong, H., Lomnicki, S., & Dellinger, B. (2008). Mechanisms of molecular product and persistent radical formation from the pyrolysis of hydroquinone. Chemosphere, 71 (1), 107-113. https://doi.org/10.1016/j.chemosphere.2007.10.007