Quantitative measurement of soot particle size distribution in premixed flames – The burner-stabilized stagnation flame approach

Abid, Aamir D.; Camacho, J.J.; Sheen, David A.; Wang, Shuangfeng

doi:10.1016/j.combustflame.2009.05.010

Cited by 152 publications

(124 citation statements)

References 49 publications

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“…In addition to the gas-phase experiments, we used HIM [12] to gain insights into the morphology of soot particles, which we sampled from atmospheric-pressure burner-stabilized flames of the above mentioned C 4 fuels [13,25,26]. For these experiments, sooting flames (/ = 2.04 for all flames; see Table 2) were stabilized on a water-cooled, atmospheric-pressure porous plug burner and the soot particles were probed at two different heights, applying the thermophoretic sampling technique [26].…”

Section: Helium-ion Microscopy (Him)mentioning

confidence: 99%

PAH formation and soot morphology in flames of C4 fuels

Schenk

Hansen

Vieker

et al. 2015

Proceedings of the Combustion Institute

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In this work, we describe experimental studies on the formation of polycyclic aromatic hydrocarbons (PAH's) in opposed-flow atmospheric-pressure flames of n-butane, i-butane, i-butene, and i-butanol and on the morphology of nascent soot particles sampled from premixed atmospheric-pressure flames of the same fuels. To identify the major contributors to the molecular growth mechanism in opposed-flow flames, we employed flame-sampling molecular-beam mass spectrometry with electron ionization (EI) and in situ gas-chromatography (GC) with mass spectrometric detection. The EI and GC-EI mass spectra indicate that several pathways with different building blocks can contribute to molecular growth. Besides the commonly accepted hydrogen-abstraction-C 2 H 2 -addition steps, we found reactions of the methyl radical to be important steps. This observation is also supported by the complexity of the mass spectra which indicates that at least one of the building blocks is rather small. The importance of phenyl radicals as building blocks seems to be limited. We also sampled nascent soot particles from premixed atmospheric-pressure flames of the above mentioned fuels and used helium-ion microscopy to unravel the influence of the fuel structure on the morphology of the sampled particles. While differences in flame temperatures and residence times are known to influence the particle sizes, the observed different morphologies are likely due to slightly different C/O ratios and potentially the chemical nature of the fuel.

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Section: Helium-ion Microscopy (Him)mentioning

confidence: 99%

PAH formation and soot morphology in flames of C4 fuels

Schenk

Hansen

Vieker

et al. 2015

Proceedings of the Combustion Institute

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“…Fig. 3 B and C show the energy band structures computed with DFT for coronene 40 and ovalene 40 , respectively. For each case the resulting n(ΔE) is found to be proportional to (ΔE-E H-L ) 2 , i.e., k = 2.…”

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confidence: 99%

Flame-formed carbon nanoparticles exhibit quantum dot behaviors

Liu

Singh

Saggese

et al. 2019

Proc. Natl. Acad. Sci. U.S.A.

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We examine the quantum confinement in the photoemission ionization energy in air and optical band gap of carbon nanoparticles (CNPs). Premixed, stretched-stabilized ethylene flames are used to generate the CNPs reproducibly over the range of 4-23 nm in volume median diameter. The results reveal that flameformed CNPs behave like an indirect band gap material, and that the existence of the optical band gap is attributed to the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap in the polycyclic aromatic hydrocarbons comprising the CNPs. Both the ionization energy and optical band gap are found to follow closely the quantum confinement effect. The optical band gaps, measured both in situ and ex situ on the CNPs prepared in several additional flames, are consistent with the theory and the baseline data of CNPs from stretched-stabilized ethylene flames, thus indicating the observed effect to be general and that the particle size is the single most important factor governing the variation of the band gap of the CNPs studied. Cyclic voltammetry measurements and density functional theory calculations provide additional support for the quantum dot behavior observed. carbon nanoparticles | quantum dots | flames N anosized carbon grains composed of disordered polycyclic aromatic hydrocarbons (PAHs) are one of the most abundant forms of carbon material in nature (1). As a less-celebrated allotrope of carbon in comparison with fullerenes, nanotubes, and graphene, carbon nanoparticle (CNP) has its share of importance in a wide range of physical phenomena. Studies of interstellar emission spectra suggest that PAH dust grains or CNPs are ubiquitous in the interstellar media (2-5); and they are considered as the tracer of the star formation process (3, 6). CNPs are formed in flames during incomplete combustion. They are part of the soot-formation process. Mature soot or atmospheric black carbon particles often contain both elemental and organic carbon, the relative amounts of which vary by source (7). Soot impacts the global and region climate systems (8, 9) because of its light-absorbing properties (10, 11) and also as cloud condensation nuclei (12). CNPs 10-20 nm in size or fine carbon particles are themselves abundant in diesel exhausts (13). Their light-absorption properties and impact on climate forcing remain poorly characterized (14). As a material, however, CNPs have found their applications in photovoltaic and electrochemical devices, including perovskite solar cells in which flame CNPs act as a hole transfer medium (15).In contrast to the notion that soot, young or mature with respect to its growth in flames, is a broadband light absorber, recent studies have shown that CNPs several nanometers in size have well-defined optical band gaps or band edges (16)(17)(18). The band gap arises from the energy gap between the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the constituent PAHs (18,19). While previous studies (16-18) explored the vari...

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“…Agglomerates of tiny carbonaceous particles are the primarily comprise of particulate emissions from diesel engines. The particulate matter character is highly vassal to the extent to which combustion progresses as preblend combustion in opposition to propagation of combustion flame [40]. Figure 7 illustrates the change in particulate emissions for different fuels used with torque measured.…”

Section: Resultsmentioning

confidence: 99%

A Comparative Study of Almond Biodiesel-Diesel Blends for Diesel Engine in Terms of Performance and Emissions

Abu‐Hamdeh

Alnefaie

2015

BioMed Research International

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This paper investigates the opportunity of using almond oil as a renewable and alternative fuel source. Different fuel blends containing 10, 30, and 50% almond biodiesel (B10, B30, and B50) with diesel fuel (B0) were prepared and the influence of these blends on emissions and some performance parameters under various load conditions were inspected using a diesel engine. Measured engine performance parameters have generally shown a slight increase in exhaust gas temperature and in brake specific fuel consumption and a slight decrease in brake thermal efficiency. Gases investigated were carbon monoxide (CO) and oxides of nitrogen (NOx). Furthermore, the concentration of the total particulate and the unburned fuel emissions in the exhaust gas were tested. A blend of almond biodiesel with diesel fuel gradually reduced the engine CO and total particulate emissions compared to diesel fuel alone. This reduction increased with more almond biodiesel blended into the fuel. Finally, a slight increase in engine NOx using blends of almond biodiesel was measured.

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Quantitative measurement of soot particle size distribution in premixed flames – The burner-stabilized stagnation flame approach

Cited by 152 publications

References 49 publications

PAH formation and soot morphology in flames of C4 fuels

PAH formation and soot morphology in flames of C4 fuels

Flame-formed carbon nanoparticles exhibit quantum dot behaviors

A Comparative Study of Almond Biodiesel-Diesel Blends for Diesel Engine in Terms of Performance and Emissions

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