Reduced Kinetic Mechanism for High-Temperature Propane Ignition

Abstract

The high-temperature ignition (above 1100 K) of propane and air mixtures is studied in this work. The initial detailed mechanism consists of 177 elementary reactions with 40 species, which reproduces the ignition time of propane under a wide range in the parametric space (initial temperature, equivalence ratio, pressure). Through a systematic reduction strategy, using the classical normalized sensitivity analysis, the minimal set of elementary chemical reactions can be reduced to 43 with 27 species, reproducing the ignition conditions. Basically, the ignition delay time corresponds to the depletion time of the propane fuel, attacked by radicals, which produces secondary fuels such as ethylene (C2H4), ethane (C2H6), and acetylene (C2H2), among others, which are consumed in times much shorter than the consumption time of the primary fuel. Thus, the radical concentrations must be properly deduced to describe correctly the ignition delay time. A 15-step global reaction mechanism is proposed and tested successfully. (c) 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 721-729, 2008