Autoignition of n-Decane/n-Butylbenzene/n-Propylcyclohexane Mixtures and the Effects of the Exhaust Gas Recirculation

Abstract

In the present work, the autoignition of single-component and binary mixtures composed of n-decane, n-butylbenzene, and/or n-propylcyclohexane has been investigated using shock-tube techniques. In addition, the effects of the presence of the exhaust gas recirculation (EGR) components on the autoignition behavior of a 4:3:3 molar n-decane: n-butylbenzene:n-propylcyclohexane surrogate mixture have been investigated experimentally. The experiments have been performed at highly diluted conditions in argon bath gas, over a wide range of temperatures (1250-1750 K), equivalence ratios (Φ = 0.2-1.5), and nominal pressures of 10-20 bar. A chemical kinetic model was developed to simulate the newly obtained experimental data by blending sub-models from the literature. In particular, the experimental and numerical analyses suggest that the observed increase in the ignition delay times in the presence of EGR is mainly due to the dilution levels and not to the chemistry of the fuel. Additional kinetic analyses were performed to compare the high-temperature autoignition properties of the different components considered herein.

Density, Viscosity, Speed of Sound, Bulk Modulus, Surface Tension, and Flash Point of Binary Mixtures of Butylbenzene + Linear Alkanes (n-Decane, n-Dodecane, n-Tetradecane, n-Hexadecane, or n-Heptadecane) at 0.1 MPa

“…Decane, dodecane, hexadecane (cetane), and n -butyl benzene are among the model compounds used to study the combustion of petroleum-based jet fuels and diesel fuels. − Model compounds are chosen because petroleum-based fuels can contain hundreds of compounds each of which can participate in potentially thousands of chemical reactions; the combustion kinetics of each component and the interactions of the components during the reactions may not be fully known; and the computation of the kinetics of all these reactions (especially multicomponent blends) is challenging. The combustion of fuels in an engine can be broken down into chemical reaction processes and physical processes.…”

“…Other surrogate mixture combustion studies have focused solely on chemical kinetic models. Comandini, et al investigated the autoignition of n -decane and its mixtures with butylbenzene and butylcyclohexane and developed chemical kinetic models of the combustion process. Yu and Ester studied the thermal oxidation of n -butylbenzene, n -dodecane, and their mixtures as a way to understand the overall oxidation of a jet fuel.…”

“…d Excess molar volume predicted at x 1 = 0.5000 from Redlich−Kister fit of excess molar volumes determined in this study. ΔV E (decane) = x 1 x 2 [0.622 + 0.082(x 1 − x 2 ) − 0.038(x 1 − x 2 ) 2 ] σ = 0.0064 cm3 •mol. ΔV E (dodecane) = x 1 x 2 [1.16 + 0.176(x 1 − x 2 ) − 0.056(x 1 − x 2 ) 2 ] σ = 0.0100 cm3 •mol.…”

“…ΔV E (tetradecane) = x 1 x 2 [1.39 + 0.255(x 1 − x 2 ) + 0.470(x 1 − x 2 ) 2 ] σ = 0.0173 cm3 •mol. ΔV E (hexadecane) = x 1 x 2 [1.63 + 0.389(x 1 − x 2 ) + 0.092(x 1 − x 2 ) 2 ] σ = 0.0035 cm3 •mol. ΔV E (heptadecane) = x 1 x 2 [1.67 + 0.653(x 1 − x 2 ) + 0.288(x 1 − x 2 ) 2 ] σ = 0.0103 cm3 •mol.…”

“…ΔV E (hexadecane) = x 1 x 2 [1.63 + 0.389(x 1 − x 2 ) + 0.092(x 1 − x 2 ) 2 ] σ = 0.0035 cm3 •mol. ΔV E (heptadecane) = x 1 x 2 [1.67 + 0.653(x 1 − x 2 ) + 0.288(x 1 − x 2 ) 2 ] σ = 0.0103 cm3 •mol.…”