Flue gas treatment for NOx by Selective Catalytic Reduction

Selective Catalytic Reduction (SCR) technology reduces emissions of oxides of nitrogen (NOx) by using a catalyst. SCR technology can achieve a reduction of up to 95 % of NOx in the combustion process and can thus meet the more stringent future legislation. New legislation will come into force under the European Directive on Industrial Emissions in 2016. The SCR process is the most efficient technology as it provides the best conversion rate.

With SCR Technology

  • The flue gas temperature at the injection point is much lower than with an SNCR system. The application temperature is ideally located around 350°C.
  • The catalyst is used to favour the reduction reactions of NOx with the selected reducing agent (urea solution) to produce nitrogen and water, thereby limiting the side reactions. It is guaranteed to deliver good results, delivering up to 95 % reduction.
  • The reagent consumption is optimised by a molar ratio close to one between the reagent and NOx to be treated.

A suitable reagent and a reliable supplier are needed for the optimum operation of the SCR system

If you choose SCR technology, the choice of reagent is essential for the optimal performance of your NOx treatment.

  • The quality of the reducing agent is important because the pollutant content or catalyst poisons must be minimal. The catalyst manufacturer demands reagent specifications that must be respected in order to optimise the lifetime of the catalyst and ensure it exceeds the validity of the contractual warranty. Using NOxCare products will ensure you have the right quality of reagent for your SCR catalyst
  • In addition, it is important to choose a reliable supplier that can ensure continuous supply of the reagent, urea. If there is a failure in the supply of reagent, the consequences are that your processing unit cannot operate. This causes an interruption in your business as it cannot meet the legal requirements in terms of reduction of NOx emissions, which are included in your site permit, in accordance with the IPPC Directive and the Directive on Industrial Emissions.