Kinetics of the consumption of CF3H, CF2 HCl and CF2O in H2/O2 flames

Richter, Hanz; Vandooren, Jacques; Tiggelen, Pierre Van

doi:10.1051/jcp/199491748

Cited by 17 publications

(14 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These results explain that the contribution of H-attack increases with the equivalence ratio of HdOdAr flames. Similar results have been noticed for the consumption of CF3H in flames (Richter et al 1994a). …”

Section: Discussionsupporting

confidence: 87%

“…Richter et al (1994a, 1 994b) have investigated experimentally with the MBMS method a flat stoichiometric flame containing 24.9% of H2, 12.7% of 02,61.4% or Ar and 1 % of CF2HCI at a pressure of 4.6 kPa. They deduced for the rate coefficient of reaction (1) CF2HCI + H+CF2H + HCI the expression kl=4.65 IOl4 exp(-773O/T) crn3mole~'s~' (Richter et al 1994a). A chemical decay mechanism (Table 1) has been suggested and modelled (Richter et al 1994b).…”

Section: Methods and Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Modelling of CF₂HCl Consumption in H₂/O₂/Ar Flames

Richter

Vandooren

Tiggelen

1994

Bulletin des Soc Chimique

View full text Add to dashboard Cite

The aim of this work is the investigation of the relative contribution of reactions (1) CF2HCI+H-CF2H+HCI, (2) CF2HCI + O-CF2CI + OH and (3) CF2HCI + OH+CF2CI + H20 to the initial CF2HCI attack in lean, stoichiometric and rich HdOdAr flames. The mole fraction profiles have been computed by means of the PREMIX code. Using thyiate coefficient kl=4.65 1014 exp(-773O/T) ~m~mole-'s-~, k2=6.62 10l2 exp(-4228/T) ~m~m o l e -~s -' and k3= 1.28 10 exp(-1671/r) cm3mole-'s-' the contribution of reactions (l), (2) and (3) has been calculated by integration throughout the flame front. The results show an obvious dependence on the equivalence ratio. In rich and stoichiometric flames CF2HCI is consumed nearly exclusively by H-radicals, while in the lean flame H contributes to 43%, 0 to 32% and OH to 25% of the CF2HCI disappearance rate. The computed results of the stoichiometric flame compare favourably with experiments.

show abstract

Section: Discussionsupporting

confidence: 87%

Section: Methods and Resultsmentioning

confidence: 99%

Modelling of CF₂HCl Consumption in H₂/O₂/Ar Flames

Richter

Vandooren

Tiggelen

1994

Bulletin des Soc Chimique

View full text Add to dashboard Cite

show abstract

“…Unit for decomposition rate is mol cm -3 s -1 be measured experimentally. The reactions which have high possibilities in the thermal plasmas are described in Table 2 involving 20 species and 17 reaction steps [10,[24][25][26][27][28][29][30][31][32][33][34][35][36][37]. The rate reaction constants were calculated at a temperature of 2,000 K which is estimated from thermodynamic calculation.…”

Section: Discussionmentioning

confidence: 99%

Decomposition Mechanism of Fluorinated Compounds in Water Plasmas Generated Under Atmospheric Pressure

Narengerile

Saito

Watanabe

2010

Plasma Chem Plasma Process

View full text Add to dashboard Cite

Decomposition mechanism of HFC-134a, and CF 4 in water plasmas at atmospheric pressure has been investigated. The decomposition efficiency of 99.9% can be obtained up to 3.17 mol kWh -1 of the ratio of hydrofluorocarbon (HFC) feed rate to the arc power and 1.89 mol kWh -1 of the ratio of perfluorocarbon (PFC) feed rate to the arc power. The species such as H 2 , CO, CO 2 , CH 4 , and CF 4 were detected from the effluent gas of both PFC and HFC decomposition. However, CH 2 F 2 and CHF 3 were observed only in the case of HFC decomposition. The HFC and PFC decomposition generate CH 2 F, CHF x (x:1-2) , and CF y (y:1-3) radicals, then those radicals were subsequently oxidized by oxygen, leading to CO and CO 2 generation in the excess oxygen condition. However, when there is insufficient oxygen available, those radicals were easily recombined with fluorine to form by-product such as CH 2 F 2 , CHF 3 , and CF 4 .

show abstract

“…Based upon those conclusions, Richter, Vandooren and Van Tiggelen [16,33,34,35] have analysed the structures of H 2 /0 2 /Ar flames seeded with CF 3 H, CF 2 HC1 and CF 2 C1 2 by means of the MBMS technique. They also measured temperature profiles with a coated thermocouple using an electrical compensation for the losses by radiation.…”

Section: ) the Analysis Of Detailedflame Structuresmentioning

confidence: 99%

“…The larger CF20 concentration is ascribed in the lean flame to the competition between reactions (7) CF 3 + OH -> CF20 + HF and (6) CF 3 + H -* CF 2 + HF. CF 2 species is consumed ultimately by processes (13) [35]. The deduction of rate coefficients [36] requires the knowledge of the individual mole fluxes and of the net reaction rates of at least one reactant or product of the investigated reaction.…”

Section: ) the Analysis Of Detailedflame Structuresmentioning

confidence: 99%

Flame Inhibition of Current Fire Extinguishers and of Potential Substitutes

Richter

Rocteur

Vandooren

et al. 1997

ACS Symposium Series

View full text Add to dashboard Cite

The replacement of the commonly used fire extinguishers CF 3 Br and CF 2 ClBr has prompted the search for new inhibitors that are less damaging to the ozone layer but as active to inhibit combustion. In this paper, four approaches are considered : 1) Influence of additives on the burning velocities, 2) Structures of inhibited flame , 3) Chemi-ionization in flames with inhibitors, 4) Numerical modeling of inhibited flame systems. From the data, a simplified chemical inhibition mechanism is discussed and the role of the bromine chemistry in inhibition is emphasized. All substitutes suggested so far that are harmless to the ozone layer are not efficient enough to replace halon 1301.After the discovery of the probable contribution of chlorofluorocarbons to stratospheric ozone depletion in 1974 by Molina and Rowland [1], the scientific debate led to the regulation of most of these compounds in the Montreal Protocol [2]. Replacement of the commonly employed fire extinguishers CF 3 Br and CF 2 ClBr has been required also because their production was discontinued as of January 1994. The search became essential for other compounds less damaging to the ozone layer but active as flame extinguishers. To move beyond experiments which essentially check the macroscopic phenomena of fire extinction as a function of the amount of extinguisher added [3], more detailed studies have been conducted in order to reach a better understanding of the chemical and physical processes responsible for flame inhibition. Four approaches have been used: 1) The influence of added compounds on the burning velocities of several flammable mixtures, 2) The analysis of inhibited flame structures, 3) The chemi-ionisation in flames seeded with inhibitors, 4) The numerical modeling of flame systems.

show abstract

Kinetics of the consumption of CF₃H, CF₂ HCl and CF₂O in H₂/O₂ flames

Cited by 17 publications

References 0 publications

Modelling of CF₂HCl Consumption in H₂/O₂/Ar Flames

Modelling of CF₂HCl Consumption in H₂/O₂/Ar Flames

Decomposition Mechanism of Fluorinated Compounds in Water Plasmas Generated Under Atmospheric Pressure

Flame Inhibition of Current Fire Extinguishers and of Potential Substitutes

Contact Info

Product

Resources

About

Kinetics of the consumption of CF3H, CF2 HCl and CF2O in H2/O2 flames

Cited by 17 publications

References 0 publications

Modelling of CF2HCl Consumption in H2/O2/Ar Flames

Modelling of CF2HCl Consumption in H2/O2/Ar Flames

Decomposition Mechanism of Fluorinated Compounds in Water Plasmas Generated Under Atmospheric Pressure

Flame Inhibition of Current Fire Extinguishers and of Potential Substitutes

Contact Info

Product

Resources

About

Kinetics of the consumption of CF₃H, CF₂ HCl and CF₂O in H₂/O₂ flames

Modelling of CF₂HCl Consumption in H₂/O₂/Ar Flames

Modelling of CF₂HCl Consumption in H₂/O₂/Ar Flames