Thermal Decomposition Kinetics of Propylcyclohexane

Published

January 21, 2009

Author(s)

Jason A. Widegren, Thomas J. Bruno

Abstract

As part of a large-scale thermophysical property measurement project, the decomposition kinetics of propylcyclohexane was investigated. Decomposition reactions were performed at 375, 400, 425, and 450 °C in stainless steel ampoule reactors. At each temperature, the extent of decomposition was determined as a function of time by gas chromatography. These data were used to derive first-order rate constants for the decomposition of propylcyclohexane. Decomposition rate constants ranged from 3.66 × 10⁻⁷ s⁻¹ at 375 °C to 8.63 × 10⁻⁵ s⁻¹ at 450 °C. Among other things, these rate constants are useful for planning property measurements at high temperatures. Based on the amount of time required for 1% of the sample to decompose (t0.01), we found that allowable instrument residence times ranged from about 8 h at 375 °C to about 2 min at 450 °C. The kinetic data were also used to determine Arrhenius parameters of A = 2.56 × 10¹⁶ s⁻¹ and E_a = 283 kJ∙mol⁻¹. In addition to the decomposition kinetics, we have also done a GC-MS analysis in order to identify the most abundant decomposition products.

Citation

Industrial and Engineering Chemistry Research

Volume

48

Issue

2

Pub Type

Journals

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Keywords

alkylcyclohexane, Arrhenius parameters, cyclic alkane, kinetic rate constants, n-propylcyclohexane, surrogate fuel, thermal decomposition

Citation

Widegren, J. and Bruno, T. (2009), Thermal Decomposition Kinetics of Propylcyclohexane, Industrial and Engineering Chemistry Research, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=832260 (Accessed October 10, 2025)