Oxidation of Propane at Elevated Pressures: Experiments and Modelling

Abstract

The oxidation of propane in air at elevated pressure was investigated in a chemical flow reactor and modelled with a comprehensive chemical kinetic model. Results are presented for pressures of 3.6. and 10 atmospheres, temperatures near 850 and 900 K, and equivalence ratio of 0.3. Gas samples were analyzed using gas chromatography with aldehydes additionally sampled using a dinitrophenylhydrazine/acetoni-trile(DNPH/ACN) procedure. Major product species observed include C₃H₆, C₂H₅. and CO: trace amounts of CH₄ and C0₂ were detected, as well as H₂ and oxygenated species including CH₂O, CH₃CHO, C₃H₆0, and C₂H₅CHO, Fuel conversion was increased with increased pressure and temperature, and the product distribution was significantly shifted in favor of C₃H₆ over C₂H₄ with increased pressure and decreased temperature. Comparison between modelling and measured results for ethylene concentrations supported the use of Tsang's recent values for the rate of propyl radical decomposition. The model compared well to fuel and major intermediates at 6 and l0atm; however, at 3atm, the model deviated significantly from the experimental results. Also, a comparison to oxygenated intermediates and H₆ indicates a need for additional model development. Major production paths are obtained from the model and discussed.