Spray ignition experiments for alkylbenzenes and alkylbenzene/n-alkane blends

FUEL

卷:195

Article

Tekawade, Aniket¹  Oehlschlaeger, Matthew A.¹ 

[1] Rensselaer Polytech Inst, Mech Aerosp & Nucl Engn, Troy, NY 12180 USA

关键词: Spray ignition;    Derived cetane number (DCN);    Alkylbenzene;    Aromatic;    Nonlinear blending;   

DOI  :  10.1016/j.fuel.2017.01.047

来源: Elsevier

【 摘 要 】

Spray ignition experiments were carried out in a heated constant volume vessel for pure n-octylbenzene and n-decylbenzene and blends of smaller alkylbenzenes (toluene, 1,3,5-trimethylbenzene, npropylbenzene, and n-butylbenzene) with n-heptane and n-decane. The experiments provide determinations of the derived cetane number (DCN) and the temperature dependence of the spray ignition delay time in air for initial ambient conditions of 650-820 K and 2.14 MPa. The alkylbenzene/n-alkane blends were found to exhibit nonlinear blending for DCN that is well explained using a proposed DCN blending model that accounts for an apparent reaction order of the blend components. Comparisons between noctylbenzene and n-decylbenzene with blends of smaller n-allcylbenzenes (toluene or npropylbenzene) and n-alkanes that seek to match functional group distributions, illustrate a synergistic reactivity promotion that occurs for n-alkylbenzenes with long chain alkyl side chain substitutions. This synergism is thought to be result of the weaker benzylic bond strengths within n-alkylbenzenes, providing increased rates of alkyl radical formation and subsequently enhanced low-temperature oxidation. Hence, this finding shows that mixtures of n-alkanes and n-alkylbenzenes with short side chains (e.g., toluene or n-propylbenzene) are not suitable surrogates to emulate low-temperature reactivity of nalkylbenzenes with long side chains. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

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