Experimental investigation and kinetic modeling of n-propylbenzene oxidation under high-pressure conditions

Abstract

In this study, oxidation experiments of n-propylbenzene (NPB) were conducted at 24 atm, with equivalence ratios (Φ = 0.5, 1.0, and 2.0), and temperatures ranging from 640-820 K. A total of 17 products and intermediates were qualitatively and quantitatively detected using gas chromatography (GC) and gas chromatography-mass spectrometry (GC–MS). The most important rate coefficients, H-abstraction reactions by OH at the α, β, and γ carbon sites of the side chain, were theoretically calculated at G4//wb97xd/6-311 + g(d,p) level. A comprehensive oxidation model of NPB, comprising 285 species and 1953 elementary reactions was constructed to understand the high-pressure oxidation. The model was extensively validated across a pressure range of 1–50 atm using oxidation data from JSR reactor, mole fraction data from shock tube, ignition delay time, and laminar flame speed. According to the selectivity of products analysis, high pressure promotes the complete progression of the reaction and reduces the formation of PAHs.