Effect of Catalysts on Gas-Phase Hydrocarbon Ignition

摘要

The effect of catalysts on the ignition of hydrocarbon fuels was experimentallystudied in a high pressure chemical flow reactor under low heat-loss Diesel engine simulated conditions. The objective of this study was to characterize the nature and magnitude of the catalytic reactions and their effect on the gas-phase ignition chemistry. Platinum, Cr2O3 (chromium oxide), and PSZ (partially stabilized zirconia) catalysts were tested with propane, propylene, n-hexane, toluene, and n-hexane/toluene mixture fuels. The parameters which were investigated include fuel structure, equivalence ratio, temperature, and pressure. With platinum, evidence of both thermal and chemical enhancement of the gas-phase ignition chemistry was observed at 6 and 10 atm under mass transport limited conditions. Thermal enhancement due to chemical heat release from the catalytic surface reactions was observed for most cases, but is most significant for near stoichiometric and fuel rich conditions. (jes)