Selective catalytic reduction (SCR) is a technology used to reduce the level of nitrogen oxides (NOx) in the presence of a catalyst. Vaporized reagent (Ammonia or Urea) is injected into flue gas and reacts with NOx on the SCR catalyst resulting in nitrogen (N2) and water (H2O).
NO2 + NO + 2 NH3 ↔ 2 N2 + 3 H2O
4 NO + 4 NH3 + O2 ↔ 4 N2 + 6 H2O
2 NO2 + 4 NH3 + O2 ↔ 3 N2 + 6 H2O
The catalyst is made from Titanium, Vanadium and Tungsten. It increases the reaction efficiency but does not deteriorate during the process. Over time the catalyst deactivates and will eventually require replacement or rejuvenating.
To inject and distribute the reagent into the flue gas flow, Yara uses an ammonia injection grid with patented designs that achieves very high mixing rates in a confined space. The result is an almost full NOx conversion at minimum ammonia slip.
The AFCU both vaporizes the reagent and regulates the flow of reagent to be injected for proper performance of the SCR. All necessary components (valves, instruments, vaporizers etc.) are assembled on a metal frame skid. The skid is connected, wired and tested by YARA prior to delivery.
SCR system has the highest level of efficiency for NOx reduction and can reach performance up to 98% reduction with less than 2 ppmvd of NH3 slip.
An SCR system is recommended when the following conditions are met:
With near 300 references in green field and retrofits SCR installation globally, we can meet your needs from design and fabrication to installation and commissioning. YARA SCR systems are capable of reaching the most stringent requirements and are present in all major industries: Coal, Oil and Gas fired Power plants, Waste to Energy, Biomass, Petrochemicals and various industrial applications.
Do you have an upcoming project for SCR system: here are the basic info we need to start a quotation. Adding link to download form.
Are you interested to review our detailed reference list. Please contact us for additional info:
The safety data sheets for our products are produced in accordance with current regulations and outline the risks associated with the use of our chemicals.