WHAT DO HIGH TEMPERATURE KINETIC MEASUREMENTS OF ACETYLENE PYROLYSIS TELL US ABOUT THE HEAT OF FORMATION OF $C_{2}H$?
Loading...
Date
1990
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Reaction profiles for $C_{2}H_{2} C_{4}H_{2}$, and $C_{6}H_{1}$ were obtained by dynamic analysis of the reflected shock zone gas by time-of-flight mass spectrometry over the temperature range $1880-2620 K$ at total reaction pressures of $\sim 0.4$ atm. The kinetic data were modeled with a new comprehensive mechanism for acetylene $pyrolysis^{1}$ which has been applied to experimental results from several laboratories. The reaction scheme features dimerization of acetylene to activated vinylacetylene which then dissociates via both molecular and radical channels. One of the sensitive reactions is $C_{2}H + H_{2} \rightarrow C_{2}H_{2} + H$ the rate of which is affected by the choice of $\Delta_{f},H (C_{2}H)$. The value employed herein is 130.4 kcal/mol which is consistent with two recent spectroscopic $determinations^{2,3}$. The use of other proposed values that are considerably higher result in significant deviations between the model calculations and the kinetic data.
Description
$^{1}$ J. H. Kiefer and W.A. Von Drasek, Int. J. Chem. Kinetics in press. $^{2}$ P.G. Green, J.L. Kinsey, and R.W. Field, J. Chem. Phys. 5160 (1989). $^{3}$ J. Segall, R. Lavi, Y. Wen, and C. Wittig, J. Chem 93, 7287 (1989).
Author Institution: Department of Chemical Engineering, University of Illinois at Chicago; Department of Chemistry, University of New Orleans
Author Institution: Department of Chemical Engineering, University of Illinois at Chicago; Department of Chemistry, University of New Orleans