SCR System

SCR(Selective Catalytic Reduction) System is used to reduce NOx in exhaust gases by a chemical reaction process. Urea is used to have the chemical reaction and it decomposes into ammonia and carbon dioxide. The ammonia decomposed from urea is chemically reacted with NOx at the surface of catalyst and then converted to nitrogen(N2) and water(H2O).



IMO(International Maritime Organization) Tier III NOx standard which becomes effective from 1 January 2016 requires 80% less NOx emissions compared with NOx Tier I. Marine diesel engine installed in ships will be forced to install SCR System which is operated in ECA by the law.


NRTEC provides detailed analysis of SCR System, assisted by its own measurements and supported by the newest software (e.g. CFD analysis). NRTEC conducts commissioning test of the SCR System under the operating conditions of ships.


  • Chamber & Silencer
  • Injection Pipe & Mixing Unit
  • Urea Dosing Unit & Urea Supply Unit
  • Soot Blower Unit
  • Pump Starter Panel


Main Components of SCR System

SCR Chamber & Silencer