Premixed lean methane/air combustion in a catalytic porous foam burner supported with perovskite LaMn0.4Co0.6O3 catalyst with different support materials and pore densities

Abstract

Methane combustion in two-zone foam burners supported with LaMn0.4Co0.6O3 catalysts is studied. The combustion stability limits are expanded by heterogeneous catalytic reactions. The upper combustion stability limits of catalytic ZrO2 burners are 75 and 65cm/s compared with those in catalytic Al2O3 burners of 65 and 60cm/s as pore density increases from 10 to 20 PPI. The central temperatures and uniformities of catalytic foams are improved compared with inert counterparts. The maximum central temperatures are improved while the pore density increases. The maximum central temperatures of catalytic Al2O3 foams are reduced when the flow velocity is higher than 50cm/s. Hydrocarbon (HC) emissions of catalytic burners (less than 450 ppm) are lower than those of inert burners (560–1130ppm). The HC emissions of ZrO2 burners are higher than those of Al2O3 burners. The carbon monoxide (CO) emissions of catalytic burners (less than 18 ppm) are lower than those of inert burners (10–34ppm) when the flow velocity is higher than 20cm/s. Nitrogen oxides (NOx) are formed by thermal pathways, and the NOx emissions of catalytic burners remain low levels of less than 2 ppm, which are lower than those of inert counterparts (3–6ppm).