1,3,5-trimethylcyclohexane pyrolysis at high pressure and temperature: Insights from theory, experiment and simulation

IF 5.8 2区工程技术 Q2 ENERGY & FUELS

Combustion and Flame Pub Date : 2025-07-18 DOI:10.1016/j.combustflame.2025.114345

Subharaj Hossain , Moirangthem Kiran Singh , Jagadeesh Gopalan , Elangannan Arunan

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Abstract

The pyrolysis of 1,3,5-trimethylcyclohexane (T135CH), which is a proposed surrogate for RP-3, has been investigated at a temperature range of 1017 - 1542 K and a pressure range of 13.4 – 23.5 bar. Mole fraction profiles of 30 pyrolysis products were obtained using GC-FID. Methane was found to be the most abundant product at high temperatures, followed by acetylene, while benzene was the most abundant aromatic product. A detailed kinetic model comprising 302 species and 967 reactions was developed, which showed reasonable agreement with the experimental data. This was aided by detailed ab initio calculations of elementary reactions at the CBS-QB3, CASSCF/MRCI levels of theory and conventional transition state theory (TST/VTST) calculations of rate parameters. The rate of production (ROP) analysis revealed that both unimolecular decomposition of T135CH (via CH₃ elimination) and H-abstraction reactions of T135CH are responsible for its consumption. Sensitivity analysis demonstrated that the CH₃ elimination channel is the most sensitive reaction for T135CH consumption. Additionally, sensitivity analysis of aromatic product formation revealed that allene (aC₃H₄) and dimethylcyclohexanyl radical (S1X35DCH) play a critical role in the formation of aromatic products. The overall rate constant for T135CH decomposition was found to be:

k / s^{- 1} = 10^{6.32 \pm 0.23} e x p^{\frac{(- 25.1 \pm 1.3 / k c a l . m o l^{- 1})}{R T}}

These findings will advance our comprehension of the unimolecular decomposition of T135CH, as well as the reaction pathways involved in the formation of its aromatic products. Ultimately, this knowledge will help us better understand the combustion process of transportation fuels.

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1,3,5-三甲基环己烷高压高温热解：理论、实验和模拟的见解

本文研究了RP-3替代物1,3,5-三甲基环己烷（T135CH）在1017 ~ 1542 K温度范围和13.4 ~ 23.5 bar压力范围下的热解过程。用GC-FID获得了30个热解产物的摩尔分数谱。在高温下，甲烷是最丰富的产物，其次是乙炔，而苯是最丰富的芳香烃产物。建立了包含302种物质和967种反应的详细动力学模型，与实验数据吻合较好。这是通过在CBS-QB3， CASSCF/MRCI理论水平上对基本反应进行详细的从头计算和常规过渡态理论（TST/VTST）计算速率参数来辅助的。产率（ROP）分析表明，T135CH的单分子分解（通过CH3消除）和T135CH的h萃取反应是其消耗的主要原因。敏感性分析表明，CH3消除通道是T135CH消耗最敏感的反应。此外，芳香产物形成的敏感性分析表明，烯（aC3H4）和二甲基环己基自由基（S1X35DCH）在芳香产物的形成中起关键作用。结果表明，T135CH的总分解速率常数为：k/s−1=106.32±0.23exp（- 25.1±1.3/kcal.mol−1）。该结果有助于进一步了解T135CH的单分子分解及其芳香族产物形成的反应途径。最终，这些知识将帮助我们更好地了解运输燃料的燃烧过程。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Combustion and Flame 工程技术-工程：化工

CiteScore

9.50

自引率

20.50%

发文量

631

审稿时长

3.8 months

期刊介绍： The mission of the journal is to publish high quality work from experimental, theoretical, and computational investigations on the fundamentals of combustion phenomena and closely allied matters. While submissions in all pertinent areas are welcomed, past and recent focus of the journal has been on: Development and validation of reaction kinetics, reduction of reaction mechanisms and modeling of combustion systems, including: Conventional, alternative and surrogate fuels; Pollutants; Particulate and aerosol formation and abatement; Heterogeneous processes. Experimental, theoretical, and computational studies of laminar and turbulent combustion phenomena, including: Premixed and non-premixed flames; Ignition and extinction phenomena; Flame propagation; Flame structure; Instabilities and swirl; Flame spread; Multi-phase reactants. Advances in diagnostic and computational methods in combustion, including: Measurement and simulation of scalar and vector properties; Novel techniques; State-of-the art applications. Fundamental investigations of combustion technologies and systems, including: Internal combustion engines; Gas turbines; Small- and large-scale stationary combustion and power generation; Catalytic combustion; Combustion synthesis; Combustion under extreme conditions; New concepts.