This variant of DeNOX technology combines advantages of both (SNCR and SCR) basic DeNOX technologies. The ERC-plus process is applied if strict requirements are made on the secondary ammonia emissions (NH3 slip) and if NOX reduction rates are required which cannot be achieved by the pure SNCR process.

The ammonia slip arising from the SNCR stage is used in the catalytic secondary cleaning stage for further nitrogen oxide reduction. Therefore, it can be guaranteed that the NH3 (ammonia slip) is very low, while maintaining high NOX reduction.

The catalytic layer is integrated into the boiler in such a way that the reaction temperature over the load range of the combustion plant is 350 to 450 °C.



1. Firing additive 2. Fuel 3. Control unit 4. SNCR stage 5. Mixing and measuring module 6. Water 7. Atomiser air 8. DeNOx additive 9. SCR stage


Advantages of the ERC-plus process:

  • Safe adherence at the limit value (mainly NH3), even in case of high NOX reduction requirements
  • Heavily reduced catalytic converter design volume (compared with SCR technology)
  • Reduced catalytic converter replacement costs
  • Minimal NH3 slip (compared with SNCR technology)
  • Complete solution from one provider


For more information, please contact us.