Experimental study and kinetic modeling of NH3/DME blends oxidation in a jet stirred reactor

IF 5.8 2区工程技术 Q2 ENERGY & FUELS

Combustion and Flame Pub Date : 2025-03-20 DOI:10.1016/j.combustflame.2025.114125

Mingyu Yu, Guangqian Luo, Ruize Sun, Li Wang, Mengli Zhou, Lingxuan Chen, Xian Li, Hong Yao

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引用次数: 0

Abstract

Since both can be obtained from renewable sources, ammonia and dimethyl ether (DME) emerge as one of the most promising fuel combination candidates. In this study, NH₃/DME oxidation experiments were conducted within a jet stirred reactor (JSR) across various operation conditions to reveal kinetics of NH₃/DME co-combustion. A detailed chemical mechanism was proposed to reasonably reproduce the measurements. The experimental results underscore the significant enhancement of DME on NH₃ oxidation, where a notable decline in the initial oxidation temperature of NH₃ was observed as the blending ratio of DME increased. At lean and stoichiometric conditions, NO concentration maintained a high level, exhibiting a consistent upward trend as the temperature progressively rose. The low NH₃/high DME blending conditions are more liable to lead to the conversion of NH₃ to NO. Whereas at rich conditions, the NO formation was inhibited. Moreover, the simulation results show that our proposed model could provide accurate predictions on the concentrations of NH₃, O₂, CO₂ and CO, but underestimate the rates of NO formation reactions. Overall, the present model has better prediction performances on NH₃/DME oxidation compared with the existing mechanism in the literatures. According to the sensitivity analysis, it is found that CH₃OCH₃(+M)=CH₃+CH₃O(+M) and H+O₂=O+OH are the major reactions that trigger production of OH and HO₂ active radicals, which promote the NH₃ oxidation reaction and the formation of NO further. While the chain termination reactions NH₂+NO=N₂+H₂O and CH₃+HO₂=CH₄+O₂ inhibit the reactivity. The HNO pathway dominates the formation of NO. With the escalation in the blending ratio of DME, the HNO pathway is strengthened, thereby causing a higher NO conversion. Above all, this research offers valuable insights into the oxidation mechanisms of NH₃/DME and provides reliable empirical data sources for model construction and optimization.

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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.