Experimental evaluation of a dual-function solution for reducing flue gas pollutants using low-temperature counter-diffusive combustion of methane with Au0.06-Pd0.06/Al2O3 Catalyst

The possibility of releasing unburned hydrocarbons and other compounds resulting from incomplete combustion from the exhaust is considered a common industrial issue. Pathing the exhaust gas through catalysts is a common way to lower the emissions. Alternatively, catalytic flameless combustion, used in a wide range of dilute air-fuel mixtures due to its optimal performance, is of interest for local radiative heating applications because of its low emission and high combustion efficiency (over 90%). However, using platinum catalysts in these systems increases production costs, and its surface temperature, ranging from 400-600 °C, faces a temperature limit in some applications. In this study, the feasibility of using a Pd-Au catalyst, with lower temperature and production costs, in a flameless catalytic counter-diffusive system was experimentally evaluated for the first time to reduce pollutants. A methane conversion rate of 98.3% in the 200-250 °C temperature range and a long life without CO and NOx pollutants were observed. This not only leads to reducing environmental pollutants, but by producing low-temperature radiant heat, it also provides the possibility of producing heat from exhaust gases, making it a dual-function solution in the field.