Selective Catalytic Reduction SystemsSource: Peerless Mfg. Co.
Selective Catalytic Reduction (SCR)
As fossil fuels are combusted in gas turbines and Heat Recovery Steam Generators (HRSGs), nitrogen oxides (NOx) are formed. To minimize the harmful effects of these undesirable pollutants, NOx emissions are stringently regulated by air quality agencies worldwide.
SCR is the most effective and proven technology to reduce NOx emissions. With guaranteed reductions greater than 90%, SCR is adaptable to a wide range of temperature and service conditions. Peerless SCR systems reduce NOx by optimally distributing ammonia over the catalyst bed, reducing NOx to harmless nitrogen and water.
Anhydrous ammonia (NH3) is the most economical reagent to use, however, the growing trend by end-users and operators is the use of aqueous ammonia (NHM40H). Aqueous ammonia is a safer reagent to transport, handle and store than anhydrous ammonia. Vaporization of the aqueous ammonia solution is required to reach the base ammonia yield needed for the reaction . Typically, this vaporization is accomplished by using a hot air source. Exhaust gas can be withdrawn from the HRSG (refer to Aqueous Exhaust Recirculating diagram), or ambient air can be heated using an electric heater (refer to Aqueous Electric diagram). Direct injection is feasible for simple-cycle gas turbines under certain design conditions.
Peerless offers performance guarantees for the entire SCR system, beginning with careful selection of the catalyst. Since Peerless can select from several catalyst manufacturers, our customers are assured the best catalyst for their particular application. This flexibility in catalyst selection ensures long-term reliability and minimal economic impact.
Computational Fluid Dynamics (CFD)
Peerless is the established leader in innovative SCR design methods that emphasize the importance of good ammonia distribution. Peerless analyzes ammonia injection grid designs and duct arrangements with Computational Fluid Dynamics (CFD), a valuable tool to optimize the overall SCR performance.
Peerless Mfg. Co., 2819 Walnut Hill Lane, Dallas, TX 75229. Tel: 214-357-6181; Fax: 214-351-0194.