Wärtsilä NOx Reducer (NOR)

The Wärtsilä NOx Reducer (NOR) is an emission after-treatment system based on the Selective Catalytic Reduction (SCR) technology for Nitrogen Oxide (NOx) reduction.

The NOR is optimized and validated for Wärtsilä medium speed engines in terms of reliability, flexibility, size and easy installation and maintenance onboard. It is available for both newbuild and retrofits and is compatible for operation on both distillate and heavy fuel oils. Furthermore, with the Wärtsilä NOx Reducer, the overall performance of the engine and exhaust gas cleaning system is optimized in  terms of emissions reduction, noise abatement and engine efficiency.  Wärtsilä provides IMO and EPA Tier III EIAPP certificates for a complete package of engine and SCR.

The Wärtsilä NOx Reducer

-          ensures you can operate with different fuels, globally

-          reduces emission based operation fees

    Technical diagram

    The main component of the NOR installation is the Reactor with a soot blowing unit and the catalyst elements, which are validated with Wärtsilä engines and with different fuel oil qualities.  Other modular essential parts of the NOR system are Power Distribution Unit, Urea pump unit, Urea dosing unit, which controls the SCR functionality and Urea Mixing and injection unit.

    NOR layout

    Product hologram


    • Arctia Offshore
      The turnkey project involved the fitting of combined Wärtsilä NOx Reducer (NOR) and Oxidation Catalysts (OXI) to the MSV Fennica and MSV Nordica.

      Arctia Offshore

    • Gitte Henning S349
      The propulsion equipment package include a Wärtsilä 9L32 main engine with new design, gear, controllable pitch propeller (CPP), HR Nozzle, Wärtsilä 8L26 auxiliary engine, as well as related equipment – including NOx reducers for both engines.

      Gitte Henning S349

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