Oxidation of butane-2,3-dione at high pressure: Implications for ketene chemistry

IF 5.8 2区工程技术 Q2 ENERGY & FUELS

Combustion and Flame Pub Date : 2024-09-28 DOI:10.1016/j.combustflame.2024.113753

Xiaoyuan Zhang , Maxence Lailliau , Yuyang Li , Yumeng Zhu , Zehua Feng , Wei Li , Philippe Dagaut

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引用次数: 0

Abstract

Ketene (CH₂CO) mechanism is a building block for developing combustion kinetic models of practical fuels. To revisit the combustion chemistry related to ketene, oxidation experiments of butane-2,3‑dione (diacetyl, CH₃COCOCH₃), considered as an effective precursor of CH₂CO, are conducted in a jet-stirred reactor (JSR) at 10 bar and temperatures ranging from 650 to 1160 K. Identification and quantification of intermediates are achieved by Fourier transform infrared spectrometry, gas chromatography, and mass spectrometry. A kinetic model of diacetyl is constructed based on recent theoretical and modeling studies on diacetyl and ketene, which has been validated against the present data and experimental data of diacetyl and CH₂CO in literature. Generally, the present model can adequately predict most of them, and better predict the methyl-related intermediates under wide pyrolysis and combustion conditions than previous models. Based on modeling analyses, the unimolecular decomposition reaction of diacetyl is the dominant reaction pathway for fuel consumption under different equivalence ratio conditions, especially at high temperatures. Under lean conditions, both the H-atom abstraction reactions by methyl (i.e. CH₃COCOCH₃ + CH₃ = CH₄ + CH₂CO + CH₃CO, R3) and by OH (i.e. CH₃COCOCH₃ + OH = H₂O + CH₂CO + CH₃CO, R5) are important for diacetyl consumption, while under rich conditions R5 becomes negligible. As the most important intermediates in diacetyl oxidation, the main consumption pathways of CH₂CO and CH₃ are dependent on the equivalence ratio conditions. Under lean conditions, CH₂CO mainly reacts with OH to produce CH₂OH and CO (i.e. CH₂CO + OH = CH₂OH + CO, R10), while methyl reacts with HO₂ to produce CH₃O and OH (i.e. CH₃ + HO₂ = CH₃O + OH, R20). In contrast, under rich conditions, the addition-elimination reaction between CH₂CO and H becomes competitive with R10, while the CH₃ self-combination producing C₂H₆ plays a more important role than the CH₃ oxidation pathway R20. Sensitivity analysis of CH₂CO shows that not only the reactions of CH₂CO, but also those of CH₃ are sensitive to CH₂CO formation. This is because CH₃ related reactions influence the distribution of radical pool, which determines the oxidation reactivity of the reaction system.

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2,3-丁二酮在高压下的氧化：对烯酮化学的影响

烯酮（CH2CO）机理是建立实用燃料燃烧动力学模型的基础。为了重新审视与烯酮有关的燃烧化学，我们在一个喷射搅拌反应器（JSR）中，在 10 巴和 650 至 1160 K 的温度范围内，对被视为 CH2CO 有效前体的丁烷-2,3-二酮（双乙酰基，CH3COCOCH3）进行了氧化实验。根据最近对双乙酰基和烯酮的理论和模型研究，构建了双乙酰基的动力学模型，并根据目前的数据和文献中双乙酰基和 CH2CO 的实验数据进行了验证。总体而言，本模型可以充分预测其中的大部分，与以前的模型相比，本模型可以更好地预测宽热解和燃烧条件下的甲基相关中间产物。根据模型分析，在不同当量比条件下，尤其是高温条件下，双乙酰的单分子分解反应是燃料消耗的主要反应途径。在贫油条件下，甲基（即 CH3COCOCH3 + CH3 = CH4 + CH2CO + CH3CO，R3）和 OH（即 CH3COCOCH3 + OH = H2O + CH2CO + CH3CO，R5）的 H 原子抽取反应对双乙酰的消耗都很重要，而在富油条件下，R5 的作用变得微不足道。作为双乙酰氧化过程中最重要的中间产物，CH2CO 和 CH3 的主要消耗途径取决于等效比条件。在贫氧条件下，CH2CO 主要与 OH 反应生成 CH2OH 和 CO（即 CH2CO + OH = CH2OH + CO，R10），而甲基则与 HO2 反应生成 CH3O 和 OH（即 CH3 + HO2 = CH3O + OH，R20）。相反，在富氧条件下，CH2CO 和 H 之间的加消反应与 R10 竞争，而产生 C2H6 的 CH3 自结合比 CH3 氧化途径 R20 起到了更重要的作用。对 CH2CO 的敏感性分析表明，不仅是 CH2CO 的反应，CH3 的反应对 CH2CO 的形成也很敏感。这是因为与 CH3 有关的反应会影响自由基池的分布，而自由基池的分布决定了反应体系的氧化反应性。

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.