scholarly journals Étude chimique et cinétique de l'oxydation homogène en phase gazeuse d'alcanes légers. II. Propane et mécanisme généralisé

1991 ◽  
Vol 69 (1) ◽  
pp. 43-61 ◽  
Author(s):  
B. Vogin ◽  
F. Baronnet ◽  
G. Scacchi
Keyword(s):  
Gas Phase ◽  
Reaction Pathways ◽  
Radical Mechanism ◽  
Parallel Reaction ◽  
Elementary Steps ◽  
Thermochemical Kinetics ◽  
Primary Products ◽  
Phase Oxidation ◽  
Gas Phase Oxidation ◽  
A Chain

An experimental study of the homogeneous gas phase oxidation of propane at 350 °C and subatmospheric pressure has been performed in order to identify and to measure the major primary products of the reaction. The experimental results have been interpreted by a chain radical mechanism, deduced from these results and from estimates of the rate constants for the elementary steps obtained by the methods of Thermochemical Kinetics. The proposed elementary steps are discussed and compared with the experimental observations. The results that we have obtained and their interpretation are compared with a similar detailed investigation performed on the oxidation of isobutane. As in the case of isobutane, two parallel reaction pathways appear, a dominant one leading to the conjugated alkene (propylene) and another one leading to the epoxide of this olefin (here propylene oxide). The oxidation of isobutane and that of propane appear to be quite similar, which corroborates the results that we have obtained. Key words: oxidation, kinetics, reaction mechanism, propane, thermochemical kinetics.

Étude chimique et cinétique de l'oxydation homogène en phase gazeuse d'alcanes légers. I. Isobutane

1989 ◽  
Vol 67 (5) ◽  
pp. 759-772 ◽  
Author(s):  
Bernard Vogin ◽  
François Baronnet ◽  
Gérard Scacchi
Keyword(s):  
Gas Phase ◽  
Reaction Scheme ◽  
Static System ◽  
Thermochemical Kinetics ◽  
Primary Products ◽  
Phase Oxidation ◽  
Major Reaction ◽  
Gas Phase Oxidation ◽  
A Chain ◽  
Reaction Routes

A literature survey on the homogeneous gas-phase oxidation of light alkanes shows that despite a rather high number of papers there are still, even in the case of isobutane, an important number of unresolved questions, which makes the writing of a reaction scheme rather difficult. To obtain more reliable experimental data, we have studied the homogeneous gas-phase oxidation of isobutane in a conventional static system, at 310 and 340 °C and subatmospheric pressure. This investigation is chiefly aimed at identifying and measuring the major primary products of the reaction. A chain radical scheme based on the primary products and on estimation of the rate constants of the elementary steps by the methods of Thermochemical Kinetics is put forward to interpret our experimental results. Two major reaction routes appear, one corresponding to the formation of isobutene and the other to the formation of isobutene oxide. The conclusions of the present investigation and suggestions for further developments are also mentioned. Keywords: oxidation, chemical kinetics, reaction mechanism, isobutane.

Kinetic analysis of coupled gas phase oxidation reaction of secondary alcohols on iridium

1979 ◽  
Vol 44 (5) ◽  
pp. 1590-1607
Author(s):  
Pavel Slouka ◽  
Ludvík Beránek
Keyword(s):  
Gas Phase ◽  
Rate Equations ◽  
Secondary Alcohols ◽  
Chain Mechanism ◽  
Competitive Reactions ◽  
Phase Oxidation ◽  
Separate Treatment ◽  
Gas Phase Oxidation ◽  
A Chain ◽  
Kinetics Of

Kinetics of partial gas phase oxidation of 2-butanol (B) and 4-methyl-2-pentanol (M) to ketones on Ir/C catalyst at 150 °C has been studied. In single reactions alcohol B was 4-7times more reactive than alcohol M, in competitive reactions the latter was twice as reactive as the former. Separate treatment of rate data for single and competitive reactions of both alcohols showed that each set could be described by nearly the same set of equations on 99% confidence level, including, of course, very different kinetic models. Confrontation of the kinetics of single and competitive reactions (comparison of the values of corresponding constants of rate equations) and the analysis of relative reactivities revealed the unfitness of Langmuir-Hinshelwood and redox models in this case. A model taking into account nonhomogeneity of the surface and a model derived on the basis of a chain mechanism would be able to describe better and in consistent way the kinetics of single and competitive reactions as well as the observed inversion of the reactivity of studied alcohols.

Gas phase oxidation of furfural to maleic anhydride on V 2 O 5 /γ-Al 2 O 3 catalysts: Reaction conditions to slow down the deactivation

2017 ◽  
Vol 348 ◽  
pp. 265-275 ◽  
Author(s):  
N. Alonso-Fagúndez ◽  
M. Ojeda ◽  
R. Mariscal ◽  
J.L.G. Fierro ◽  
M. López Granados
Keyword(s):  
Maleic Anhydride ◽  
Gas Phase ◽  
Reaction Conditions ◽  
Phase Oxidation ◽  
Gas Phase Oxidation

scholarly journals Volatility of secondary organic aerosol during OH radical induced ageing

2011 ◽  
Vol 11 (21) ◽  
pp. 11055-11067 ◽  
Author(s):  
K. Salo ◽  
M. Hallquist ◽  
Å. M. Jonsson ◽  
H. Saathoff ◽  
K.-H. Naumann ◽  
...  
Keyword(s):  
Gas Phase ◽  
Organic Aerosol ◽  
Oh Radical ◽  
High Concentration ◽  
Volatile Material ◽  
Phase Oxidation ◽  
Gas Phase Oxidation ◽  
Institute Of Technology ◽  
Set Up ◽  
Pinic Acid

Abstract. The aim of this study was to investigate oxidation of SOA formed from ozonolysis of α-pinene and limonene by hydroxyl radicals. This paper focuses on changes of particle volatility, using a Volatility Tandem DMA (VTDMA) set-up, in order to explain and elucidate the mechanism behind atmospheric ageing of the organic aerosol. The experiments were conducted at the AIDA chamber facility of Karlsruhe Institute of Technology (KIT) in Karlsruhe and at the SAPHIR chamber of Forchungzentrum Jülich (FZJ) in Jülich. A fresh SOA was produced from ozonolysis of α-pinene or limonene and then aged by enhanced OH exposure. As an OH radical source in the AIDA-chamber the ozonolysis of tetramethylethylene (TME) was used while in the SAPHIR-chamber the OH was produced by natural light photochemistry. A general feature is that SOA produced from ozonolysis of α-pinene and limonene initially was rather volatile and becomes less volatile with time in the ozonolysis part of the experiment. Inducing OH chemistry or adding a new portion of precursors made the SOA more volatile due to addition of new semi-volatile material to the aged aerosol. The effect of OH chemistry was less pronounced in high concentration and low temperature experiments when lower relative amounts of semi-volatile material were available in the gas phase. Conclusions drawn from the changes in volatility were confirmed by comparison with the measured and modelled chemical composition of the aerosol phase. Three quantified products from the α-pinene oxidation; pinonic acid, pinic acid and methylbutanetricarboxylic acid (MBTCA) were used to probe the processes influencing aerosol volatility. A major conclusion from the work is that the OH induced ageing can be attributed to gas phase oxidation of products produced in the primary SOA formation process and that there was no indication on significant bulk or surface reactions. The presented results, thus, strongly emphasise the importance of gas phase oxidation of semi- or intermediate-volatile organic compounds (SVOC and IVOC) for atmospheric aerosol ageing.

Experimental and Modeling Study of the Selective Homogeneous Gas Phase Oxidation of Methane to Methanol

1995 ◽  
Vol 34 (4) ◽  
pp. 1044-1059 ◽  
Author(s):  
Rune Lodeng ◽  
Odd A. Lindvaag ◽  
Paal Soraker ◽  
Per T. Roterud ◽  
Olav T. Onsager
Keyword(s):  
Gas Phase ◽  
Oxidation Of Methane ◽  
Phase Oxidation ◽  
Gas Phase Oxidation ◽  
Modeling Study

Effect of Vanadia Doping and Its Oxidation State on the Photocatalytic Activity of TiO2 for Gas-Phase Oxidation of Ethene

2008 ◽  
Vol 112 (48) ◽  
pp. 19102-19112 ◽  
Author(s):  
K. Bhattacharyya ◽  
S. Varma ◽  
A. K. Tripathi ◽  
S. R. Bharadwaj ◽  
A. K. Tyagi
Keyword(s):  
Photocatalytic Activity ◽  
Gas Phase ◽  
Oxidation State ◽  
Phase Oxidation ◽  
Gas Phase Oxidation
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