Kinetics of the reaction: H+HI?H2+I at 298 K and very low pressures

Abstract

The reaction was studied at 298 K and millitorr pressures em-1

Kinetic Analysis of Ethyl Iodide Pyrolysis Based on Shock Tube Measurements

“…The optimization of a kinetic model of the pyrolysis of ethyl iodide was carried out on the basis of reflected shock wave experiments with H‐ARAS and I‐ARAS detection , and rate coefficient measurements from Michael et al , and Vasileiadis and Benson . Arrhenius parameters A and E of the following four reactions were determined in the temperature range 950–1400 K and a pressure range of 1–2 bar: (R1): C 2 H 5 I → C 2 H 5 + I; (R3): C 2 H 5 I → C 2 H 4 + HI; (R4): H + HI → H 2 + I; (R5): C 2 H 5 I + H →C 2 H 5 + HI.…”

“…The uncertainty limits are indicated only in the temperature range of our measurements (950-1400 K). The numbered thin lines show previously published rate coefficients: (1) Kumaran et al [20] (p = 0.1-0.7 bar), (2) Yang and Conway [25] (p = 0.02 bar), (3) Shilov and Sabirova [26], (4) Ogg [27] (p = 0.2 bar), (5) Sullivan [17] (p = 0.2 bar), (6) Yang and Tranter [19] (p = 0.07-0.16 bar; plotted values are the high-pressure extrapolation), (7) Benson and Bose [28] (p = 0.08-0.25 bar), (8) Butler and Polanyi [29] (p = 0.002-0.017 bar), (9) Michael et al [11], (10) Vasileiadis and Benson [13], (11) Baulch et al [9], (12) Lorenz et al [16], (13) Sullivan [30], and (14) Yuan et al [21] Arrhenius parameters showed a significantly better agreement with the experimental results compared to the simulations performed with the initial parameters.…”

“…The optimization of the model for the pyrolysis of ethyl iodide was based on 29 ARAS measurements, the measured rate coefficient of reaction (R4) by Vasileiadis and Benson and the 13 measured rate coefficients for the reverse reaction of (R4) from Michael et al . We assumed that the measured hydrogen and iodine concentrations have absolute errors (), and the measured rate coefficients have relative errors ().…”

“…The 13 measured rate coefficient values were converted to the forward rate coefficients using the program MECHMOD based on the thermodynamic data. Vasileiadis and Benson measured the rate coefficient of reaction (R4) at 298 K using a very‐low‐pressure reactor technique and mass spectrometric detection. These rate coefficients were also handled as experimental data during the optimization.…”

“…This standard deviation was deduced from the scatter of the measured rate coefficients. The rate coefficient measured by Vasileiadis and Benson was assigned an uncertainty of 10% based on the authors’ estimation.…”