Aqueous ammonia is ammonia (NH₃) dissolved in water.
It is used as a reducing agent in SNCR and SCR systems, where it provides the ammonia required to react with nitrogen oxides.
Compared with anhydrous ammonia, aqueous ammonia offers a different handling and storage profile because the ammonia is supplied as a solution rather than in its water-free form.
However, aqueous ammonia remains a hazardous, corrosive chemical and requires appropriately designed storage, handling and dosing systems.
For Energy From Waste operators, aqueous ammonia offers several operational characteristics:
- A consistent reagent for NOx reduction
- Compatibility with appropriately designed SNCR and SCR systems
- Availability in different concentrations
- Suitability for automated dosing and process control
- Established use in industrial flue gas treatment
The correct concentration depends on the plant’s reagent handling infrastructure, dosing equipment and process requirements.
The role of aqueous ammonia in Energy From Waste
Energy From Waste facilities recover energy from residual waste through controlled combustion.
During this process, nitrogen oxides can form within the combustion gases.
EfW operators must manage these emissions as part of their environmental permit obligations.
Aqueous ammonia can be introduced into the flue gas treatment process to reduce NOx concentrations before the gases reach the stack.
The performance of the abatement system depends on accurate reagent dosing, suitable operating temperatures and effective mixing.
For plant operators, the objective is to achieve the required NOx reduction while controlling reagent consumption and limiting ammonia slip.
What is ammonia slip?
Ammonia slip occurs when some of the ammonia introduced into the abatement process remains unreacted and passes downstream.
Excessive ammonia slip can create operational and environmental issues, including the formation of ammonium salts and associated deposits under certain conditions.
Maintaining the correct balance between NOx reduction and ammonia consumption is therefore an important aspect of system optimisation.
Why ammonia concentration and consistency matter
The performance of a NOx abatement system depends partly on the consistency of the chemical reagent.
Variations in ammonia concentration can affect the amount of active reagent delivered by a dosing system.
For facilities operating continuously, a consistent product specification supports predictable reagent management and process control.
Blended Products supplies aqueous ammonia in several concentrations, including:
Aquamonia 190
A 19% aqueous ammonia solution suitable for a range of applications.
Aquamonia 245
A 24.5% aqueous ammonia solution suitable for industrial applications, including appropriately designed flue gas treatment systems.
Aquamonia 330
A 33% aqueous ammonia solution for industrial applications requiring a higher concentration product.
Selection between concentrations should reflect the site’s equipment design, operating requirements and safety assessment.
Choosing a reliable UK ammonia supplier
For Energy From Waste facilities, aqueous ammonia is often a process-critical consumable.
An interruption in reagent supply can affect the plant’s ability to maintain its required emissions performance.
Selecting an ammonia supplier should therefore involve more than comparing the delivered price per tonne.
Important considerations include:
Product specification
A consistent concentration and appropriate quality documentation support predictable reagent dosing and process performance.
Supply continuity
Reliable availability is essential for facilities operating continuously.
Delivery capability
Bulk deliveries must be coordinated around site access, storage capacity and operational requirements.
Technical knowledge
An experienced supplier should understand the product, its handling requirements and the importance of maintaining dependable deliveries.
Supply chain resilience
Alternative sourcing arrangements, logistics capability and effective communication can help reduce exposure to supply disruption.
Blended Products: a UK ammonia supplier for industrial applications
Blended Products Ltd is an independent UK supplier of industrial gases and chemicals, including aqueous and anhydrous ammonia.
The company supplies aqueous ammonia for applications including NOx abatement, water treatment and chemical manufacturing.
For Energy From Waste operators, Blended Products offers:
- Aquamonia 245 and Aquamonia 330
- Bulk aqueous ammonia supply
- Deliveries using specialist tankers and ISO tanks
- Product documentation and technical support
- Experienced chemical logistics management
- UK-wide supply capabilities
Blended Products’ approach combines specialist product knowledge with a focus on responsive service and dependable supply.
For operators reviewing their current ammonia procurement arrangements, supplier resilience can be an important part of maintaining long-term operational performance.
Frequently asked questions
What is NOx abatement?
NOx abatement refers to technologies and processes used to reduce nitrogen oxide emissions from combustion and industrial operations. SNCR and SCR are two established methods that use reducing agents such as ammonia to convert NOx primarily into nitrogen and water.
How does ammonia reduce NOx emissions?
Ammonia reacts with nitrogen oxides under suitable operating conditions. In SNCR systems, the reaction takes place at high temperatures. In SCR systems, a catalyst promotes the reaction at lower temperatures.
What is the difference between SCR and SNCR?
SCR uses a catalyst to support NOx reduction and generally achieves higher removal efficiencies. SNCR operates without a catalyst and relies on suitable high-temperature conditions.
Why is aqueous ammonia used in Energy From Waste plants?
Aqueous ammonia provides the reducing agent required for NOx abatement in suitable SCR and SNCR systems. It helps facilities control nitrogen oxide emissions and meet their environmental permit requirements.
What is ammonia slip in NOx abatement?
Ammonia slip is the amount of unreacted ammonia remaining in the flue gas after the abatement process. It can be influenced by reagent dosing, temperature, mixing and system performance.
What concentration of aqueous ammonia is used for NOx abatement?
Different concentrations can be used depending on plant design and reagent handling requirements. Blended Products supplies 24.5% and 33% aqueous ammonia solutions, among other available grades.
Where can I find a UK ammonia supplier for NOx abatement?
Blended Products supplies aqueous ammonia to UK industrial customers, including businesses operating flue gas treatment systems. Its team can discuss product specifications, bulk supply and delivery requirements.