Investigation on the NOx Emission Characteristics of Methane-Hydrogen Co-Firing for Industrial Combustor

This study investigated the NOx emission characteristics of methane-hydrogen co-combustion and hydrogen combustion. A multi-hole type flat flame (FF) burner was utilized as an industrial burner, and the tests were carried out with variations in air-fuel and co-firing ratio. The current investigation showed a minimum difference in the combustion and NOx-emission characteristics in the methane-hydrogen co-firing tests, at least up to 50% hydrogen co-combustion conditions. In the hydrogen combustion conditions, on the other hand, the amount of NOx emissions was significantly increased along with a flashback, which could produce additional heat to a burner surface. Additional tests with a greater amount of air showed that it is able to reduce the NOx emission level, and the heating of the burner surfaces as well.