Effects of ferrocene addition on soot formation characteristics in laminar premixed burner-stabilized stagnation ethylene flames

• Published in: Journal of aerosol science Vol. 175; p. 106265
• Main Authors: Zhou, Yuxin, He, Qingyan, Sha, Yutong, Shen, Chang, You, Xiaoqing
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-01-2024
• Subjects: Ferrocene; Premixed flames; Soot formation; Soot formation; Premixed flames; Ferrocene
• ISSN: 0021-8502; 1879-1964
• DOI: 10.1016/j.jaerosci.2023.106265

The influence of ferrocene addition (∼60 ppm on a molar basis) on soot formation in laminar premixed burner-stabilized stagnation ethylene flames (with an equivalence ratio of 2.0) is investigated both experimentally and computationally. The results show that ferrocene addition has a very small effect on both flame temperature and concentrations of small soot precursors from kinetic modeling, but apparently promotes soot inception and particle size growth from particle size distribution measurements, and decreases soot maturity from elemental analysis. Transmission electron microscope (TEM) images and energy dispersive spectrometry (EDS) results show that distinct iron cores are present in large soot aggregates, consistent with the kinetic modeling results that iron predominates over iron oxide in ferrocene-doped flames. Iron in the incipient soot may be too dispersed or form too small cores to be observed by TEM; and as the soot particles coagulate, iron in the soot coalesces into large cores. Since iron is not exposed on the soot surface, and the concentrations of soot precursors are also not significantly increased by ferrocene, ferrocene promotes soot size growth mainly through enhanced coagulation rather than surface growth.
•The influence of ferrocene addition at ppm level on soot formation in premixed ethylene flames is investigated.•Ferrocene shows a very small effect on both flame temperature and soot precursors.•Ferrocene apparently promotes both soot inception and size growth, and decreases soot maturity.•Ferrocene promotes soot size growth mainly through enhanced particle coagulation.