Does a high O2 content in coke oven flue gas affect the SCR denitration efficiency?

Yes, an excessively high O2 content in coke oven flue gas can affect the denitration efficiency of SCR. SCR (Selective Catalytic Reduction) denitration involves using a catalyst to react nitrogen oxides (NOx) in flue gas with ammonia (NH3), thereby producing harmless nitrogen and water. In the SCR reaction, an appropriate amount of oxygen is necessary, but too high an O2 content will reduce the denitration efficiency of SCR. When the O2 content in the coke oven flue gas is too high, the excess oxygen competes with ammonia for reaction sites, causing these active sites on the SCR catalyst to be occupied by oxygen. This reduces the opportunities for NOx to react with ammonia to form nitrogen, thereby lowering the denitration efficiency. Therefore, an excessively high O2 content in coke oven flue gas can affect the selectivity and efficiency of SCR denitration. To improve the denitration efficiency of SCR, it is necessary to control the O2 content in the coke oven flue gas and keep it within an appropriate range, so as to ensure that the SCR catalyst can make full use of ammonia to react with NOx and achieve an efficient denitration process. .

Excess oxygen content generally does not affect the performance of SCR catalysts, but it does influence the calculated values of nitrogen oxide emissions. In other words, the total amount of nitrogen oxides treated by the SCR system remains unchanged; however, when using an 8% oxygen factor for calculation, the higher the actual oxygen content, the higher the calculated value. This creates the illusion of low SCR denitration efficiency, but it is actually a matter of standard-based calculations. It is recommended that you check the requirements specified in the air pollutant emission standards.