SCR (Selective Catalytic Reduction)

De-NOx SCR catalyst removes the NOx contained in exhaust gases discharging from power plants, industrial boilers, ships, incinerators, chemical plants and diesel automobiles etc. SCR Catalyst SCR (Selective catalytic reduction) is a typical De-NOx technology which deoxidizes NOx to Nitrogen on the surface of catalyst. Ammonia and Urea are used for reductant and then NOx is reduced to Nitrogen and water at lower temperature due to the SCR catalyst. This technology has been widely used in industrial facility since it showed a high reduction rate of NOx up to 90%. SCR Reaction Mechanism Comparison of De-NOx Technology Technology SCR SNCR Low Nox Burner Outline - Inject NH3 to the catalyst- reduce NOx - Inject UREA/NH3- NOx reduction without catalyst - Combustion method- Lower oxygen concentration and flame temperature NOx removal rate 70~90% 25~50% 30~50% Investment High Low Medium Operation Expense Medium High Low Consideration - Installallation space- Catalyst removal and replacement - Stucture of combustion furnace- Residence time of reductant - Fan capacity- Stability of flame Overall Evaluation - Applied to medium & large facility - Restrict the operation condition- Existing customer unsatifaction factors - Suitable for small facility- Existing the limited NOx removal rate Comparison of air regulation invarious countries