Improved sooting tendency measurements for aromatic hydrocarbons and their implications for naphthalene formation pathways

The sooting propensities of binary mixtures of n-heptane and toluene on one hand, and isooctane and toluene on the other hand are evaluated in haust gas recirculation (EGR). The evolution of the sooting propensity as a function of both toluene mole fraction in the binary mixtures and CO 2 content of the air stream can then be revealed. The sooting tendencies of both kinds of blends decrease in a very linear way with increasing CO 2 content of the air stream. On the opposite, the sooting tendencies of isooctane/toluene blends follow a strongly non-linear relationship with the toluene mole fraction due to synergistic effects while YSIs of n-heptane/toluene blends show very linear trends. Interestingly, these trends match those observed on other configurations of diffusion flames, further strengthening the consistency of the YSI methodology. The combined effects of fuel blending and CO 2 dilution are also exhibited. All these trends can be of great importance for further investigations as toluene and isooctane mole fractions found in commercially available gasoline and gasoline surrogate fuels are prone to affect soot formation through a strong synergistic effect as identified in current study.

“…The experimental setup used to reproduce the methodology prescribed by McEnally and Pfefferle [23] has been carefully described in Ref. 24.…”

Section: Experimental Methodologymentioning

confidence: 99%

Section: Experimental Methodologymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Sooting propensities of some gasoline surrogate fuels: Combined effects of fuel blending and air vitiation

Kashif

Bonnety

Matynia

et al. 2015

“…In particular, n-propylbenzene (nPB) embodies well the properties of a class of alkyl benzenes in jet and diesel fuels [3,4]. Previous studies have targeted several combustion characteristics of nPB, including ignition delay [5], laminar burning velocity [6] and sooting tendency [7]. The earlier work by Litzinger at al.…”

Section: Introductionmentioning

confidence: 99%

Reactions of HO2 with n-propylbenzene and its phenylpropyl radicals

Altarawneh

Dlugogorski

2015

Abstraction of an H atom from the propyl side chain by hydroperoxyl radicals (HO 2 ) constitutes a central reaction in the low-temperature oxidation of n-propylbenzene (nPB).Herein, we calculate reaction rate constants for H abstraction from primary, secondary and benzylic sites in nPB. Rate of abstraction of a benzylic H atom dominates that of a secondary H atom with negligible abstraction of the primary H atom at T ≥ 600 K. We present the reaction enthalpies for 1-phenyl-1-propyl (R1), 1-phenyl-2-propyl (R2) and 1-phenyl-3-propyl (R3) radicals, and compare the computed reaction rate constants and bond dissociation enthalpies with analogous scarce literature values. Addition of HO 2 radicals to radical sites in R1, R2 and R3 proceeds in a highly exothermic process and results in the formation of HO 2 -phenylpropyl adducts. Mapped potential energy surfaces illustrate all plausible exit channels of the three HO 2 -phenylpropyl adducts. Master equation calculations for the three phenylpropyl + HO 2 reactions indicate that direct O-OH bond fission and water elimination control the fate of the adducts leading to the formation of ketonic-type structures. Results from this study should be useful to update kinetic models for the low-temperature oxidation of alkylbenzenes in general.

“…Recently, McEnally and Pfefferle [9] investigated potential methodologies to improve the Smoke-Point measurement. These authors assessed the relevance of the Yield Sooting Index (YSI) that quantifies the propensity of the fuel investigated to produce soot.…”

mentioning

confidence: 99%

Simultaneous soot temperature and volume fraction measurements in axis-symmetric flames by a two-dimensional modulated absorption/emission technique

Legros

Wang

Bonnety

et al. 2015

multaneous soot temperature and volume fraction measurements in axis-symmetric flames by a twodimensional modulated absorption/emission technique. Combustion and Flame, Elsevier, 2015, 162, pp.2705 -2719. <10.1016/j.combustflame.2015 AbstractThe original contribution of the present paper is to present a joint theoretical and experimental approach to implement the modulated absorption/emission technique. Two-dimensional fields of soot temperature and volume fraction can then be measured simultaneously in a reference steady laminar coflow axis-symmetric non-premixed ethylene flame estalished over * Corresponding author Email addresses: guillaume.legros@dalembert.upmc.fr (Guillaume Legros ), wangqianlong212@gmail.com (Qianlong Wang), jerome.bonnety@upmc.fr (Jérôme Bonnety), muhammad.kashif@ucp.edu.pk (Muhammad Kashif), celine.morin@univ-valenciennes.fr (Céline Morin), jean-louis.consalvi@univ-amu.fr (Jean-Louis Consalvi),