NOx reduction by SNCR and SCR systems with ammonia solution

The ammonia solution (or aqueous ammonia) comes from the dissolution of ammonia gas into water. This solution can be used directly in SNCR and SCR systems.

The ammonia solution is more secure in use than anhydrous ammonia since vapor pressure is greatly reduced by the presence of water. With proper storage and proper handling, this reagent can be safely used to control NOx emissions. Yara has produced and delivered ammonia for over a century, all over the world.

For NOx control, Yara recommends using ammonia solution where possible.

Why choose ammonia solution?

Yara's ammonia solution may suit your needs for the following reasons:

  • More effective than urea, with a lower hazard level than for anhydrous ammonia, it therefore offers a good compromise
  • The risks associated with the transport, storage and use of ammonia solution are much lower than with anhydrous ammonia. Because ammonia is dissolved in water, its vapor pressure is reduced, which allows storage at ambient temperature and pressure
  • Compared to urea aqueous solutions, ammonia solutions are more efficient in terms of transport and storage. NOxCare ammonia solution 25% contains 9.5% more nitrogen than the 40% NOxCare urea solution
  • When higher NOx reductions are required, ammonia has several advantages compared to Urea:


  • Less secondary reactions to the formation of nitrogen oxides and carbon moNOxide
  • Greater efficiency than urea in SNCR systems at high temperatures
  • Reduced likelihood of soiling and corrosion of downstream equipment injection
  • Leakage of the urea solution leads to the formation of a white salt precipitates and makes your equipment look aged. This is avoided with the use of ammonia solution.

Safe and reliable deliveries

We transport the ammonia solution onto your site anywhere in the world by:

  • Road transport (tank truck)
  • Rail (freight wagon)

Inland navigation / (ship / barge)
If you have specific questions about Yara’s ammonia solution, please contact our expert NOx control.

Telemetry and secure storage of the ammonia solution used for the reduction of NOx
For your peace of mind, Yara can install telemetry on your storage unit. With Yara’s telemetry system, your stock of reagent is measured remotely and in real time. Yara is responsible for keeping the stock level of ammonia you decide.

If you have a question related to telemetry, do not hesitate to ask our expert on NOx control.

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