Ion chemistry in premixed rich methane flames

Journal Article · Thu Jan 24 23:00:00 EST 2019 · Combustion and Flame

DOI:https://doi.org/10.1016/j.combustflame.2019.01.009· OSTI ID:1492799

Chen, Bingjie ^[1]; Wang, Haoyi ^[1]; Wang, Zhandong ^[1]; Han, Jie ^[1]; Alquaity, Awad B. S. ^[2]; Wang, Heng ^[1]; Hansen, Nils ^[3]; Sarathy, S. Mani ^[1]

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1. King Abdullah Univ. of Science and Technology (KAUST), Thuwal (Saudi Arabia)
2. King Abdullah Univ. of Science and Technology (KAUST), Thuwal (Saudi Arabia); RWTH Aachen Univ., Aachen (Germany)
3. Sandia National Lab. (SNL-CA), Livermore, CA (United States)

External electric field and plasma assisted combustion show great potential for combustion enhancement, e.g., emission and ignition control. To understand soot suppression by external electric fields and flame ignition in spark ignition engines, flame ion chemistry needs to be investigated and developed. In this work, comprehensive and systematic investigations of neutral and ion chemistry are conducted in premixed rich methane flames. Cations are measured by quadrupole molecular beam mass spectrometry (MBMS), and neutrals are measured by synchrotron vacuum ultra violet photoionization time of flight MBMS (SVUV-PI-TOF-MBMS). The molecular formula and dominant isomers of various measured cations are identified based on literature survey and quantum chemistry calculations. Experimentally, we found that H₃O⁺ is the dominant cation in slightly rich flame (Φ = 1.5), but C₃H₃⁺ is the most significant in very rich flames (Φ = 1.8 and 2.0). An updated ion chemistry model is proposed and used to explain the effects of changing equivalence ratio. To further verify key ion-neutral reaction pathways, measured neutral profiles are compared with cation profiles experimentally. Furthermore, detailed cation and neutral measurements and numerical simulations by this work help to understand and develop ion chemistry models. Deficiencies in our current understanding of ion chemistry are also highlighted to motivate further research.

• Research Organization: Sandia National Laboratories (SNL-CA), Livermore, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: AC04-94AL85000
• OSTI ID: 1492799
• Report Number(s): SAND2019-0468J; 671590
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: C Vol. 202; ISSN 0010-2180
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY