Atmospheric chemistry of trans-CF&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt;CH=CHF: products and mechanisms of hydroxyl radical and chlorine atom initiated oxidation

Javadi, M. S.; Søndergaard, Roar R.; Nielsen, Ole John; Hurley, M. D.; Wallington, Timothy J.

doi:10.5194/acp-8-3141-2008

Cited by 30 publications

(25 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The formation of CF 3 C(O)CHCl 2 via reaction (11) was evident in the product spectra by comparison with the reference spectra for CF 3 C(O)CHCl 2 (see Fig. 2).…”

Section: Fate Of the Cf 3 Ch(o)chcl 2 Radicalmentioning

confidence: 95%

Atmospheric chemistry of t-CF₃CHCHCl: products and mechanisms of the gas-phase reactions with chlorine atoms and hydroxyl radicals

Andersen

Nielsen

Hurley

et al. 2012

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

FTIR-smog chamber techniques were used to study the products and mechanisms of the Cl atom and OH radical initiated oxidation of trans-3,3,3-trifluoro-1-chloro-propene, t-CF(3)CH=CHCl, in 700 Torr of air or N(2)/O(2) diluent at 296 ± 2 K. The reactions of Cl atoms and OH radicals with t-CF(3)CH=CHCl occur via addition to the >C=C< double bond; chlorine atoms add 15 ± 5% at the terminal carbon and 85 ± 5% at the central carbon, OH radicals add approximately 40% at the terminal carbon and 60% at the central carbon. The major products in the Cl atom initiated oxidation of t-CF(3)CH=CHCl were CF(3)CHClCHO and CF(3)C(O)CHCl(2), minor products were CF(3)CHO, HCOCl and CF(3)COCl. The yields of CF(3)C(O)CHCl(2), CF(3)CHClCOCl and CF(3)COCl increased at the expense of CF(3)CHO, HCOCl and CF(3)CHClCHO as the O(2) partial pressure was increased over the range 10-700 Torr. Chemical activation plays a significant role in the fate of CF(3)CH(O)CHCl(2) and CF(3)CClHCHClO radicals. In addition to reaction with O(2) to yield CF(3)COCl and HO(2) the major competing fate of CF(3)CHClO is Cl elimination to give CF(3)CHO (not C-C bond scission as previously thought). As part of this study k(Cl + CF(3)C(O)CHCl(2)) = (2.3 ± 0.3) × 10(-14) and k(Cl + CF(3)CHClCHO) = (7.5 ± 2.0) × 10(-12) cm(3) molecule(-1) s(-1) were determined using relative rate techniques. Reaction with OH radicals is the major atmospheric sink for t-CF(3)CH=CHCl. Chlorine atom elimination giving the enol CF(3)CH=CHOH appears to be the sole atmospheric fate of the CF(3)CHCHClOH radicals. The yield of CF(3)COOH in the atmospheric oxidation of t-CF(3)CH=CHCl will be negligible (<2%). The results are discussed with respect to the atmospheric chemistry and environmental impact of t-CF(3)CH=CHCl.

show abstract

“…The formation of CF 3 C(O)CHCl 2 via reaction (11) was evident in the product spectra by comparison with the reference spectra for CF 3 C(O)CHCl 2 (see Fig. 2).…”

Section: Fate Of the Cf 3 Ch(o)chcl 2 Radicalmentioning

confidence: 95%

Atmospheric chemistry of t-CF₃CHCHCl: products and mechanisms of the gas-phase reactions with chlorine atoms and hydroxyl radicals

Andersen

Nielsen

Hurley

et al. 2012

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…These GWP estimates rely on chemical knowledge concerning the decomposition of the HFO and of its onward degradation products. It is known that atmospheric decomposition of HFO-1234ze yields trifluoroacetaldehyde (CF 3 CHO) with 100% molar yield [6], which is then removed from the atmosphere 4× faster than its progenitor via photolysis [7]. Studies dating back to the 1950s suggest that photolysis leads to trifluoromethyl (CF 3 ) and formyl (CHO) radicals [8][9][10] that lead to atmospherically less hazardous CO 2 and HF [6].…”

Section: Main Textmentioning

confidence: 99%

“…Because the rate coefficient for reaction with OH is very slow, this 1% quantum yield results in (11.0 ± 5.5)% of CF 3 CHO molecules in the atmosphere decomposing via this CHF 3 pathway, resulting in a secondary GWP = 1400 ± 700 for CF 3 CHO. CF 3 CHO is formed in 100% molar yield from the atmospheric decomposition of HFO-1234ze [6] as well as from the decomposition of other HFOs [25] and HFCs [26]. This introduces a concern that HFOs being considered as replacement gases for air conditioning and other industrial uses might have significant impact as climate change agents.…”

Section: Implications For Hfo Usementioning

confidence: 99%

Photodissociation of CF3CHO provides a new source of CHF3 (HFC-23) in the atmosphere: implications for new refrigerants.

Hansen

Campbell

Kable

2021

Preprint

View full text Add to dashboard Cite

Throughout the last century, chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) were the most widely used refrigerants. However, it was discovered that they released reactive chlorine in the upper atmosphere causing the hole in the ozone layer and they were phased out by the 1987 Montreal Protocol [1]. They were replaced by hydrofluorocarbons (HFCs), which contain no chlorine and do not damage the ozone layer. However, HFCs are potent greenhouse gases and they were phased out in a 2016 amendment to the Montreal Protocol [2]. The latest evolution of these refrigerants is the hydrofluoroolefins (HFOs). These molecules have no chlorine and incorporate a carbon-carbon double bond to greatly reduce their atmospheric lifetime, and hence their contribution as a greenhouse gas. In this work, we demonstrate that one of the most important HFOs in current use ultimately decomposes partially into HFC-23 (CHF3) in the atmosphere. HFC-23 is one of the most potent greenhouse gases known, and the most potent HFC. Despite its phaseout, the observed emissions of HFC-23 have been increasing recently and were the largest in history in 2018 with no conclusive explanation [3]. This work suggests that the production of HFOs might be partially responsible.

show abstract

“…More recent studies have revised the GWP of HFO1234ze(E) to less than 1 [7]. In addition, it has been estimated that the decay products of HFO1234ze(E) in the atmosphere have a negligible environmental impact [8].…”

Section: Rpc Operation With Environment-friendly Gasesmentioning

confidence: 99%

Studies on tetrafluoropropene-based gas mixtures with low environmental impact for Resistive Plate Chambers

Bianchi¹,

Delsanto²,

Dupieux³

et al. 2020

J. Inst.

View full text Add to dashboard Cite

A: Gaseous detectors are widely used in high-energy physics experiments, and in particular at the CERN Large Hadron Collider (LHC), to provide tracking and triggering over large volumes. It has been recently estimated that Resistive Plate Chambers (RPC), used for muon detection, have the highest contribution on the overall greenhouse gas (GHG) emissions at the LHC experiments.Gas mixtures for RPCs are mainly made of C 2 H 2 F 4 , which is a greenhouse gas with a high environmental impact in the atmosphere. C 2 H 2 F 4 is already phasing out of production, due to recent European Union (EU) regulations, and its cost is expected to increase in the near future. Therefore, finding alternative gas mixtures made of gas components with a low Global Warming Potential (GWP) has become extremely important for limiting the GHG emissions as well as for economic reasons.The novel hydrofluoroolefins are likely appropriate candidates to replace C 2 H 2 F 4 due to their similar chemical structures. This study is focused on the characterization of innovative gas mixtures with tetrafluoropropene HFO1234ze(E) (C 3 H 2 F 4 ) that is one of the most eco-friendly hydrofluoroolefins, thanks to its very low GWP. HFO1234ze(E)-based gas mixtures with the addition of Ar, N 2 , O 2 and CO 2 are extensively discussed in this paper as well as the role of i-C 4 H 10 and SF 6 in such mixtures.

show abstract

Atmospheric chemistry of trans-CF<sub>3</sub>CH=CHF: products and mechanisms of hydroxyl radical and chlorine atom initiated oxidation

Cited by 30 publications

References 19 publications

Atmospheric chemistry of t-CF₃CHCHCl: products and mechanisms of the gas-phase reactions with chlorine atoms and hydroxyl radicals

Atmospheric chemistry of t-CF₃CHCHCl: products and mechanisms of the gas-phase reactions with chlorine atoms and hydroxyl radicals

Photodissociation of CF3CHO provides a new source of CHF3 (HFC-23) in the atmosphere: implications for new refrigerants.

Studies on tetrafluoropropene-based gas mixtures with low environmental impact for Resistive Plate Chambers

Contact Info

Product

Resources

About

Atmospheric chemistry of trans-CF&lt;sub&gt;3&lt;/sub&gt;CH=CHF: products and mechanisms of hydroxyl radical and chlorine atom initiated oxidation

Cited by 30 publications

References 19 publications

Atmospheric chemistry of t-CF3CHCHCl: products and mechanisms of the gas-phase reactions with chlorine atoms and hydroxyl radicals

Atmospheric chemistry of t-CF3CHCHCl: products and mechanisms of the gas-phase reactions with chlorine atoms and hydroxyl radicals

Photodissociation of CF3CHO provides a new source of CHF3 (HFC-23) in the atmosphere: implications for new refrigerants.

Studies on tetrafluoropropene-based gas mixtures with low environmental impact for Resistive Plate Chambers

Contact Info

Product

Resources

About

Atmospheric chemistry of trans-CF<sub>3</sub>CH=CHF: products and mechanisms of hydroxyl radical and chlorine atom initiated oxidation

Atmospheric chemistry of t-CF₃CHCHCl: products and mechanisms of the gas-phase reactions with chlorine atoms and hydroxyl radicals

Atmospheric chemistry of t-CF₃CHCHCl: products and mechanisms of the gas-phase reactions with chlorine atoms and hydroxyl radicals