Selective Catalytic Reduction

ME Production´s emission reduction systems are based on proven emission reduction technologies.

Our advanced NOx reduction systems use SCR technology – Selective Catalytic Reduction – which is recognized as one of the most cost-effective and fuel-efficient technologies available for the reduction of NOx.

The basic principle of SCR is to reduce NOx emissions by injecting a liquid-reductant agent through a special catalyst into the exhaust stream. This sets off a chemical reaction that converts the nitrogen oxides – NOx – present in the diesel engine’s exhaust gas into nitrogen, water and CO2.

With its superior return environmentally as well as economically, SCR is considered one of the most viable solutions to the emission limit challenge.

At ME Production, we are uncompromising when it comes to quality and work with leading marine engine and SCR catalyst manufacturer Haldor Topsoe.

NOx reduction systems based on SCR technology include the following components:

  • SCR reactor
  • Storage tank for reducing agent
  • High pressure injection pump for reducing agent – dosing unit
  • High pressure nozzle for urea injection
  • Exhaust gas mixer
  • Flow control system
  • Emission analyzer

SCR Reactor

An SCR NOx emission reduction system is a simple system and the reactor is the key component. The catalyst is the heart of the reactor for it is within the catalyst itself the chemical reaction takes place converting harmful NOx to harmless nitrogen, water, oxygen and Co2.

We use Haldor Topsoe’s patented DNX catalysts, which have been specially designed for DeNOx. They are of the corrugated type based on porous, fiber-reinforced titanium (TiO2) carrier, which is homogeneously impregnated with the active components: oxides of tungsten and vanadium. The monolithic structure is made with different geometry (hydraulic diameters) for different particulate loadings of the gas to be treated.

The main features of the Topsoe DNX catalysts are their well-defined and controlled tri-modal pore structure. The porous structure provides the catalysts with a large internal area where the active components are finely dispersed on the entire surface. This provides a large number of active sites and thus high activity i.e. high NOx conversion rates.

The special features of the manufacturing process result in a catalyst with a considerably lower weight than steel plate and extruded honeycomb type catalysts. In addition to the advantages of lower weight the fiber-reinforcement of renders structural flexibility to the monolithic structure providing it with an exceptional resistant to thermal as well as mechanical shocks. In combination with a high porosity, this makes the catalyst extremely responsive to rapid changes in plant load compared to denser, extruded or plate-type, catalysts.

The DNX catalysts have been designed for use with all reciprocating engines and therefore they are able to withstand heavy exhaust pulsation and engine vibrations. The catalysts are encased in steel sheet elements, which can be easy to installed and replaced in a sturdy framework to form modules.


The MEP – NOx SCR uses proven SCR technology to reduce NOx emissions. With its superior return environmentally as well as economically, SCR is considered one of the most viable solutions to the emission limit challenge.

Our MEP – NOx SCR system is composed of the following components:

  1. SCR unit: The SCR unit contains the catalyst elements. Here urea is injected into the exhaust stream to set off a chemical reaction that converts the NOx present in the diesel engine’s exhaust gas into harmless nitrogen, water and CO2. The SCR unit design is always customized according to the individual vessel and the available space on board. Both horizontal and vertical designs are available.
  2. Urea injection: Urea is injected into the exhaust gas flow through an advanced nozzle. The injection system is important to ensure that urea is mixed homogeneously with the exhaust gas in order to maximize the NOx removal performance.
  3. Urea dosing pump: The correct amount of urea is supplied to the injection nozzle by the urea dosing pump. The urea dosing process is continuously controlled according to the exhaust gas flow and engine load.
  4. Urea tank: Urea is supplied from the urea tank where a sufficient amount of urea is stored based on the ship’s individual needs.
  5. Gas sample NOx measurement: The NOx reduction rate is continuously monitored and logged directly after the SCR unit. Furthermore, exhaust gas samples are tested and the NOx removal performance logged.


  • Cost-effective solution to emissions regulations
  • We offer turnkey solutions
  • We provide customized designs for retrofit installations
  • Solution includes complete control and monitoring system
  • Low weight and space-saving compact modular design
  • Easy installation


Read more in our product describtion, SOX SCR – click here to open.