Combustion of CH 4 /H 2 /Air Mixtures in Catalytic Microreactors

The combustion of CH 4 and H 2 in a confined space represents an innovative way to produce heat and power. Burning tests on CH 4 /H 2 /air mixtures using Pd/NiCrO 4 ‐catalyst‐lined SiC monoliths (see picture) show an important reduction of both the ignition temperature and the 100 % conversion temperature in these systems.The combustion of CH 4 /H 2 /HC mixtures in a very small space represents an alternative, innovative way to produce thermal/electrical energy. Pd/NiCrO 4 catalysts are lined on SiC monoliths via in situ solution combustion synthesis (SCS), and the monoliths are then tested by feeding CH 4 , H 2 , and lean CH 4 /H 2 mixtures into a lab‐scale test rig at an output thermal power of 7.6 MW th   m −3 . In all cases, the combustion temperature shifts to values lower than those observed in non‐catalytic combustion. When the power density is kept constant (by adding H 2 to the gas mixture), the value of CH 4 –T 50 (the half‐conversion temperature of CH 4 ) decreases relative to that of pure CH 4 , and the slope of the conversion curve becomes steeper. The higher the H 2 concentration is, the higher the reactivity of the mixture towards CH 4 oxidation—probably due to a higher production of H 2 reactive radicals (OH).