Experimental Studies on Lean Premixed Catalytic Combustion of Natural Gas and Theoretical Analyses

Abstract Lean premixed catalytic combustion of natural gas was studied over the catalyst supports washcoated with palladium, lanthanum, strontium and manganese. The experimental results showed that the temperatures of the flameless catalytic combustion ranged from 600 to 900 ℃ and very low temperature led to extinguishment and very high temperature made the catalyst disabled. In the experiments, the natural gas-air ratios ranged from 4 % to 12 % by volume and in some given conditions, the good catalytic effect was fulfilled at the ratio of 8 % and catalytic combustion would extend the range of the fuel-air ratio, which was not very strict with the fuel concentration. Meanwhile, the experiments proved that in the shorter monolith, catalytic combustion was in very good condition and the surface temperatures of monolith were relatively low. Oppositely, in the longer monolith, the surface temperatures increased and the lethal gas emissions were slightly increased，which will do much harm to the environment. Subsequently, the performances of heat and mass transfer in catalytic support were analyzed.