Nitric oxide emissions from a premixed propane-air flame were controlled by extracting energy from a steady state reaction zone using a cooled flat flame porous metal disk burner. Energy flux variations and, hence, nitric oxide formation rate changes were obtained for specific mixtures by changing the fuel-air inlet velocity. It was possible to stabilize flames for inlet flow velocities of from 3 cm/sec. up to approximately twice the laminar burning velocity of the mixture. Data were obtained for pressures of 5, 25 and 40psig and equivalence ratios from 0.7 to 1.3. Nitric oxide concentrations were reduced by more than a factor of 10 compared to the adiabatic case. However, energy fluxes to the porous disk of over 25 per cent of the lower heating value of the fuel were observed. Hydrocarbon emissions were less than 10 ppm hexane and the carbon monoxide levels were equal to the chemical equilibrium concentrations.
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