Experimental study on the thermal oxidation of 2-chlorophenol in air over the temperature range 450–900°C

Briois, C.; Visez, Nicolas; Baillet, C.; Sawerysyn, Jean-Pierre

doi:10.1016/j.chemosphere.2005.07.033

Cited by 22 publications

(12 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The homogeneous gas-phase precursor's mechanism of PCDD/Fs formation under oxidation conditions has been extensively studied both experimentally (Evans and Dellinger, 2004;Briois et al, 2006) and theoretically (Altarawneh et al, 2007;Xu et al, 2011;Zhang et al, 2014). The available kinetic models of this mechanism proposed by Babushok and Tsang (2003) and Khachatryan et al (2003) are originated from Shaub and Tsang (1983) model, and may be used in the low temperature range for estimation of radiationinduced PCDD/Fs formation in the EBDS process.…”

Section: Dioxins Formation Under Irradiationmentioning

confidence: 98%

Modeling study of polychlorinated dibenzo-p-dioxins and dibenzofurans behavior in flue gases under electron beam irradiation

Gerasimov

2016

Chemosphere

View full text Add to dashboard Cite

Section: Dioxins Formation Under Irradiationmentioning

confidence: 98%

Modeling study of polychlorinated dibenzo-p-dioxins and dibenzofurans behavior in flue gases under electron beam irradiation

Gerasimov

2016

Chemosphere

View full text Add to dashboard Cite

“…Under high-temperature conditions, CTPs can readily form chlorothiophenoxy radical (CTPRs), sulfydryl-substituted phenyl radical, and thiophenoxyl diradical by losing the sulfydryl-H, the H/Cl atom combined to the carbon in the adjacent position of the carbon with -SH group, and both the sulfydryl-H and the ortho-substituted H/Cl, respectively, via abstraction reactions by H, OH, Cl, or O( 3 P). Although sulfydryl-substituted phenyl radicals and thiophenoxyl diradicals have not yet been detected in combustion and thermal processes, their oxygenated counterparts hydroxyl-substituted phenyl radicals and phenoxyl diradicals have been identified and proposed to be potential precursors for PCDD/DF formation [32,33,34,35]. In their theoretical studies, Yu et al and Pan et al proved the formation feasibility of sulfydryl-substituted phenyl radicals and thiophenoxyl diradicals from CTPs and the formation feasibility of hydroxyl-substituted phenyl radicals and phenoxyl diradicals from CPs, and also proved the corresponding energetically favorable contributions to the formation of PCTA/DT and PCDD/DFs, respectively [27,36].…”

Section: Introductionmentioning

confidence: 99%

Quantum Chemical and Kinetic Study on Radical/Molecule Formation Mechanism of Pre-Intermediates for PCTA/PT/DT/DFs from 2-Chlorothiophenol and 2-Chlorophenol Precursors

Zuo

Wang

Pan

et al. 2019

IJMS

View full text Add to dashboard Cite

Polychlorinated phenoxathiins (PCPTs), polychlorinated dibenzothiophenes (PCDTs), and polychlorinated thianthrenes (PCTAs) are sulfur analogues of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/DFs). Chlorothiophenols (CTPs) and chlorophenols (CPs) are key precursors for the formation of PCTA/PT/DTs, which can react with H or OH to form chloro(thio)phenoxy radical, sulfydryl/hydroxyl-substituted phenyl radicals, and (thio)phenoxyl diradicals. However, previous radical/radical PCTA/DT formation mechanisms in the literature failed to explain the higher concentration of PCDTs than that of PCTAs under the pyrolysis or combustion conditions. In this work, a detailed thermodynamics and kinetic calculations were carried out to investigate the pre-intermediate formation for PCTA/PT/DTs from radical/molecule coupling of the 2-C(T)P with their key radical species. Our study showed that the radical/molecule coupling mechanism explains the gas-phase formation of PCTA/PT/DTs in both thermodynamic and kinetic perspectives. The S/C coupling modes to form thioether-(thio)enol intermediates are preferable over the O/C coupling modes to form ether-(thio)enol intermediates. Thus, although the radical/molecule coupling of chlorophenoxy radical with 2-C(T)P has no effect on the PCDD/PT formation, the radical/molecule coupling of chlorothiophenoxy radical with 2-C(T)P plays an important role in the PCTA/PT formation. Most importantly, the pre-PCDT intermediates formation pathways from the couplings of sulfydryl/hydroxyl-substituted phenyl radical with 2-C(T)P and (thio)phenoxyl diradicals with 2-C(T)P are more favorable than pre-PCTA/PT intermediates formation pathways from the coupling of chlorothiophenoxy radical with 2-C(T)P, which provides reasonable explanation for the high PCDT-to-PCTA ratio in the environment.

show abstract

“…The homogeneous gas-phase self- and cross- dimerization of these radicals as well as CTPRs could be the initial and important step for the formation of PCTA/DTs [30]. Although sulfydryl-substituted phenyl radicals and thiophenoxyl diradicals have not yet been identified in combustion and thermal processes, their oxygenated counterparts phenyl radicals and phenoxyl diradical have been detected and proposed to be highly active and have great potential for the gas-phase formation of PCDD/DFs [31,32,33,34,35]. A theoretical study by Pan et al has also proved the formation feasibility of phenyl radicals and phenoxyl diradicals and their energetically favorable contribution to PCDD/DF formation [36].…”

Section: Introductionmentioning

confidence: 99%

Mechanistic and Kinetic Study on Self-/Cross- Condensation of PCTA/DT Formation Mechanisms from Three Types of Radicals of 2,4-Dichlorothiophenol

Wang

Zuo

Zheng

et al. 2019

IJMS

View full text Add to dashboard Cite

Chlorothiophenols (CTPs) are known to be key and direct precursors of polychlorinated thianthrene/dibenzothiophenes (PCTA/DTs). Self/cross-coupling of the chlorothiophenoxy radicals (CTPRs), sulfydryl-substituted phenyl radicals and thiophenoxyl diradicals evolving from CTPs are initial and important steps for PCTA/DT formation. In this study, quantum chemical calculations were carried out to investigate the homogenous gas-phase formation of PCTA/DTs from self/cross-coupling of 2,4-dichlorothiophenoxy radical (R1), 2-sulfydryl-3,5-dichlorophenyl radical (R2) and 3,5-dichlorothiophenoxyl diradical (DR) at the MPWB1K/6-311+G(3df,2p)//MPWB1K/6-31+G(d,p) level. The rate constants of crucial elementary steps were deduced over 600–1200 K, using canonical variational transition state theory with a small curvature tunneling contribution. For the formation of PCTAs, the S•/σ-C• condensation with both thiophenolic sulfur in one radical and ortho carbon in the other radical bonded to single electron is the most efficient sulfur-carbon coupling mode, and the ranking of the PCTA formation potential is DR + DR > R2 + DR > R1 + DR > R1 + R2 > R1 + R1. For the formation of PCDTs, the σ-C•/σ-C• coupling with both ortho carbon in the two radicals bonded to single electron is the energetically favored carbon-carbon coupling mode, and the ranking of the PCDT formation potential is: R2 + DR > R2 + R2 > R1 + DR > R1 + R2 > R1 + R1. The PCTA/DTs could be produced from R1, R2 and DR much more readily than PCDD/DFs from corresponding oxygen substituted radicals.

show abstract

Experimental study on the thermal oxidation of 2-chlorophenol in air over the temperature range 450–900°C

Cited by 22 publications

References 17 publications

Modeling study of polychlorinated dibenzo-p-dioxins and dibenzofurans behavior in flue gases under electron beam irradiation

Modeling study of polychlorinated dibenzo-p-dioxins and dibenzofurans behavior in flue gases under electron beam irradiation

Quantum Chemical and Kinetic Study on Radical/Molecule Formation Mechanism of Pre-Intermediates for PCTA/PT/DT/DFs from 2-Chlorothiophenol and 2-Chlorophenol Precursors

Mechanistic and Kinetic Study on Self-/Cross- Condensation of PCTA/DT Formation Mechanisms from Three Types of Radicals of 2,4-Dichlorothiophenol

Contact Info

Product

Resources

About