Reducing NOx with SNCR and SCR systems using Urea reagent

Urea is an important raw material for the chemical industry. It is widely used in NOx control systems to reduce nitrogen oxides emissions. Yara is a leading urea producer, and has been supplying Urea to its customers  for many years, including for use to reduce NOx emissions.

  • With SNCR systems,  urea is often the reagent choice for safety reasons.  However, it is less efficient than ammonia as urea needs to be converted to ammonia prior to the NOx reduction process.

  • We supply either solid urea, typically for dilution on site, or urea solution in various concentrations.

Why urea could be for you:

  • you may wish to choose urea for safety reasons. It poses less risks in the workplace and doesn’t require specific training, unlike ammonia.

  • urea is non hazardous.  It is stable, non volatile, non explosive and  non flammable

  • it can be safely transported, stored and handled without the need for specific training

The disadvantage of using urea as a reagent in NOx control

  • urea can lead to additional nitrous oxide or carbon monoxide emissions (poisonous gases)

  • it is less effective than ammonia

  • there is an increased probability of fouling and corrosion in equipment downstream of the injection point

  • leakages of urea solution leads to white salt precipitates giving an ageing look to your equipment

  • scaling and clogging when blended with hard water for deNOx operation

  • Urea solutions must be provided with sufficient heat to avoid freezing. The freezing point is dependent on the concentration with 40% starting to freeze at 0°C.

Yara is one of the largest urea producers in the world, offering a unique urea back-up supply.  Our NOx control experts can provide you with technical support and advice to ensure that your SNCR urea NOx control system is cost efficient and meets all the requirements needed. Yara delivers the reagent of your choice from our unique network of plants offering a constant back-up in sourcing.

Urea / Urea solution transport means include:

  • Truck (solid packed) / Silo Truck (bulk)

  • Container (solid packed and bulk)

  • Railcar (solid packed and bulk)

  • Vessel / Barge (solid packed and bulk)

Contact our NOx control expert for more information on reliable deliveries of urea, or read more on how to reduce your NOx control reagent costs.

NOx Reduction Technology Reagents


Reliable Supply of NOxCare 40, Yara's high-purity urea solution, delivered globally, according to AUS40 ISO 18611 for maritime use during the operation of a vessel.

For queries, please contact:
noxcare.marine@yara.com