The C₅ chemistry preceding the formation of polycyclic aromatic hydrocarbons in a premixed 1-pentene flame

Journal Article · Mon May 27 00:00:00 EDT 2019 · Combustion and Flame

DOI:https://doi.org/10.1016/j.combustflame.2019.05.013· OSTI ID:1526228

Ruwe, Lena ^[1]; Cai, Liming ^[2]; Moshammer, Kai ^[3]; Hansen, Nils ^[4]; Pitsch, Heinz ^[2]; Kohse–Höinghaus, Katharina ^[1]

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1. Bielefeld University (Germany)
2. RWTH Aachen University (Germany)
3. Physikalisch Technische Bundesanstalt (PTB), Braunschweig (Germany)
4. Sandia National Lab. (SNL-CA), Livermore, CA (United States)

We report the formation of small polycyclic aromatic hydrocarbons (PAHs) and their precursors can be strongly affected by reactions of C5 species. For improving existing combustion mechanisms for small PAH formation, it is therefore valuable to understand the fuel-specific chemistry of C5 fuels. To this end, we provide quantitative isomer-resolved species profiles measured in a laminar premixed (Φ = 1.8) low-pressure (4 kPa) flame of 1-pentene with photoionization molecular-beam mass spectrometry (PI-MBMS) using tunable synchrotron vacuum-ultraviolet (VUV) radiation. These experimental results are accompanied with numerical simulations, starting from models from the literature by Wang et al. [JetSurF version 2.0 (2010)] and Healy et al. [Energy Fuels 24 (2010) 1521–1528] that were developed for different fuels, but which include 1-pentene as an intermediate, and by Narayanaswamy et al. [Combust. Flame 157 (2010) 1879–1898] focusing on the small PAH chemistry. Taking observed discrepancies between experimental results and simulations into consideration, a mechanism for C₅ chemistry was newly developed including PAH formation pathways, and its performance analyzed in detail. Special emphasis was placed on the initial fuel consumption of 1-pentene as well as on formation pathways of small aromatics. The mechanisms show differences regarding fuel decomposition and hydrocarbon growth reactions. These contribute to noticeable differences between the simulations with different models on one hand, and deviations between model predictions and experimental results on the other. While the new model presents overall satisfactory capabilities to predict the mole fraction profiles of common combustion intermediates, the predictive capability of the literature models was not fully satisfying for some intermediate species, including C₄H₆, C₇H₈, and C₁₀H₈. Lastly, the results indicate that the fuel-specific C₅ reaction routes as well as the mechanism for small PAH formation need further investigation.

• Research Organization: Sandia National Lab. (SNL-CA), Livermore, CA (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: AC04-94AL85000; NA0003525; AC02-05CH11231
• OSTI ID: 1526228
• Alternate ID(s): OSTI ID: 1562955
• Report Number(s): SAND-2019-5116J; 675316
• Journal Information: Combustion and Flame, Vol. 206, Issue C; ISSN 0010-2180
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
1-PenteneAlkene combustion
Molecular-beam mass spectrometry
Aromatics formation
Chemical modeling