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SNCR Technology

Selective Non-Catalytic Reduction (SNCR) is usually installed as an addon to primary low NOx combustion technology. Because annual chemical costs are typically the largest consideration, the core design principle of our SNCR system is to optimise chemical injection locations and maximise mixing to increase chemical utilisation.

Through advanced feedback control algorithms and on-site tuning, the system adapts to load and temperature changes in the furnace to preferentially introduce chemicals where the temperature is most favourable for NOx reduction. This technique increases the efficiency of reactivity, decreasing reocurring chemical usage.

Our Approach to SNCR

  • Maximising low NOx combustion before considering SNCR
  • Temperature measurement is one of the most important design parameters
  • CFD of SNCR chemistry to locate nozzles
  • Nozzles engineered with different angles
  • Multi elevation for load change
  • Adjustable urea concentration
  • Individual lance urea flow control
  • High chemical utilisation efficiency
  • Low water usage to minimise efficiency loss
  • Reliable system


Models of furnace temperature (upper), urea injection trajectory (middle) and NOx concentration (lower) of SNCR system, as applied to a 700MW boiler.



SNCR urea distribution skids.


Model of furnace outlet NOx concentration without (left) and with urea injection (right) for a 350MW tower furnace burning lignite.