摘要 |
Fuel such as coal is combusted in a staged combustion device in a method comprising feeding into a first combustion stage of said furnace said fuel and gaseous oxidant containing more than 21 vol. % oxygen, and preferably 21.8 to 29 vol. % oxygen, at a stoichiometric ratio below that which, if the stage were operated with air as the only oxidant, would produce the same amount of NOx, and combusting said fuel with said gaseous oxidant in said combustion stage to produce combustion products and unburned fuel.
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