Chemical inhibition of laminar propane flames by organophosphorus compounds has been studied experimentally and computationally using a detailed chemical kinetic reaction mechanism. Both fuel-lean (0.9) and fuel-rich (1.2) propane flames were studied at one atmosphere to examine the role of equivalence ratio in flame inhibition. The experiments examined a wide variety of organophosphorus compounds. We report on experimental species flame profiles propane doped flames with 1200 PPM tri-methyl phosphate (TMP) and compare them with modeled species flame profile results of TMP and dimethyl methyl phosphonate (DMMP). The unburned reactant temperature is 380 K. Both experiments and kinetic modeling indicate that inhibition efficiency is effectively the same for all of the organophosphorus compounds examined, independent of the molecular structure of the initial inhibitor molecule. A more generalized form of the Twarowski mechanism is developed to account for the results observed, and new theoretical values are determined for heats of formation of the important P-containing species, using the BAC-G2 method.
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Korobeinichev, O. P., V. M. Shvartsberg, A. G. Shmakov, T. A. Bolshova, T. M. Jayaweera, C. Melius, W. J. Pitz, and C. K. Westbrook, "Flame Inhibition by Phosphorus-Containing Compounds in Lean and Rich Propane Flames," Proceedings of the Combustion Institute 30, Issue 2, pp. 2350-2357, 2004; Lawrence Livermore National Laboratory, Livermore, CA, UCRL-CONF-201585.