Urea for NOx Control

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 choose urea as a reagent to control NOx emissions:

• 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 of your NOx reduction system when urea blended with hard water is used for 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.

Reliability of Supply

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 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 include:

• 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.

Anti scaling solution

Resolving scaling problems when using Urea reagent in SNCR systems

Some SNCR systems in plants using urea solution require the addition of water to dilute the urea prior to injection. If urea is used with hard water, this can lead to scaling issues, eg plugging of injection nozzles, which results in downtime. Yara has developed a NOxCare anti-scaling solution for trouble free NOx control SNCR systems.

Download more information on our SNCR Urea Anti Scaling solution (pdf)

Yara's expertise

Our expertise and reliability in urea supplies and optimized cost reduction

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 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.

Contact our NOx control expert for more information on reliable deliveries of urea, or read more on how to prevent scaling of your equipment.