METHODS FOR REDUCING NOx IN COMBUSTION FLUE GAS USING METAL-CONTAINING ADDITIVES

摘要

Various methods for decreasing the amount of nitrogen oxides released to the atmosphere as a component of combustion gas mixtures are provided. The methods specifically provide for the removal of nitric oxide and nitrogen dioxide (NOx) from gas mixtures emitted from stationary combustion systems. In particular, methods for improving efficiency of nitrogen oxide reduction from combustion systems include injecting metal-containing compounds into the main combustion zone (22) and/or the reburning zone (24) of a combustion system. The metal-containing compounds react with active combustion species, and these reactions change radical concentrations and significantly improve NOx conversion to molecular nitrogen. The metal-containing additives can be injected with the main fuel (30), in the main combustion zone (22), with secondary or reburning fuel addition (36) or at several locations (28) in the main combustion zone (22) and reburning zone (26). Optionally, nitrogenous reducing agents and/or overfire air (38) can be injected downstream (26) to further increase NOx reduction.