Experimental and Chemical Kinetic Modeling Study of Dimethylcyclohexane Oxidation and Pyrolysis

Abstract

A combined experimental and chemical kinetic modeling study of the high-temperature ignition and pyrolysis of 1,3-dimethylcyclohexane (13DMCH) is presented. Ignition delay times are measured behind reflected shock waves over a temperature range of 1049–1544 K and pressures of 3.0–12 atm. Pyrolysis is investigated at average pressures of 4.0 atm at temperatures of 1238, 1302, and 1406 K. By means of mid-infrared direct laser absorption at 3.39 μm, fuel concentration time histories are measured under ignition and pyrolytic conditions. A detailed chemical kinetic model for 13DMCH combustion is developed. Ignition measurements show that the ignition delay times of 13DMCH are longer than those of its isomer, ethylcyclohexane. The proposed chemical kinetic model predicts reasonably well the effects of equivalence ratio and pressure, with overall good agreement between predicted and measured ignition delay times, except at low dilution levels and high pressures. Simulated fuel concentration profiles agree reasonably well with the measured profiles, and both highlight the influence of pyrolysis on the overall ignition kinetics at high temperatures. Sensitivity and reaction pathway analyses provide further insight into the kinetic processes controlling ignition and pyrolysis. The work contributes toward improved understanding and modeling of the oxidation and pyrolysis kinetics of cycloalkanes.

Structure‐dependence in initial decomposition of trans‐1,2‐dimethylcyclohexyl isomers: Kinetic exploration and conformational analysis

“…And they proposed that 1,2DMCH has the lowest ignition reactivity resulting from the less favors CC β‐scissions in cyclic ring, and thus leads to yield the less small olefins and more conjugate olefins. Eldeeb et al had come to the same conclusion that 1,3DMCH has larger ignition delay time than ECH during the high temperature ignition processes [2]. More recently, Tian et al [3] reported that 1,2,4‐trimethylcyclohexane (T124MCH) would yield more obvious hydrocarbon, aromatic, and oxidized intermediates by comparing with cyclohexane, n‐propylcyclohexane and 1,2,4‐trimethylbenzene in their experimental and modeling study.…”

“…Combustion chemistry of cycloalkanes has been caught much attention and motivated the ongoing researches because of their importance in real fuels [1][2][3][4][5][6]. For instance, cycloalkanes comprise 30% of conventional diesel [2], 20% of jet fuel [2], and 10%-30% of automotive and aviation gasoline [7].…”

“…Combustion chemistry of cycloalkanes has been caught much attention and motivated the ongoing researches because of their importance in real fuels [1][2][3][4][5][6]. For instance, cycloalkanes comprise 30% of conventional diesel [2], 20% of jet fuel [2], and 10%-30% of automotive and aviation gasoline [7]. Moreover, an increasing portion of cycloalkanes would be expected in future transportation fuels for the development of oil-sandderived, coal liquefaction oils, and other alternative energy sources [1,8].…”

“…Moreover, an increasing portion of cycloalkanes would be expected in future transportation fuels for the development of oil-sandderived, coal liquefaction oils, and other alternative energy sources [1,8]. As such, given the urgent demands of cycloalkanes, great efforts have been made in experimental measurements, kinetic modeling, and theoretical computations [1][2][3][7][8][9][10]. These aim to gain insight into their combustion properties and fundamentally uncover the detailed chemical mechanisms, particularly for low temperature oxidation chemistry, to promote stable, efficient, and clean combustion in practical applications [8,9,11,12].…”

Experimental and Kinetic Modeling of Biomass Derived Hydrocarbon p-Menthane Pyrolysis

“…Rakotoalimanana et al , investigated the pyrolysis behavior of n -butylcyclohexane at 100 MPa and 375–425 °C with a detailed kinetic model proposed, in which they emphasized that the aromatics generation under low temperature was through stepwise dehydrogenation and side chain breaking. Eldeeb et al conducted the pyrolysis experimental study of dimethylcyclohexane at 4 atm and temperature of 1238, 1302, and 1406 K, and then they developed the kinetic model based on the primary model of methylcyclohexane pyrolysis. Both the proposed kinetic model and similar pyrolysis behavior can provide references for the construction of detailed kinetic models for the pyrolysis of PMT (Figure ).…”