PrimePurity

Ammonia Slip Catalyst (ASC)

An Ammonia Slip Catalyst (ASC) is a downstream catalytic stage designed to eliminate excess, unreacted ammonia (NH₃) from process or exhaust gas streams. It converts ammonia into harmless nitrogen (N₂) and water (H₂O), thereby ensuring compliance with strict emission standards.

Working Principle

Origin of ammonia
In modern flue gas treatment systems, ammonia (NH₃), often generated from urea injection, is used as a reducing agent in Selective Catalytic Reduction (SCR) to convert nitrogen oxides (NOₓ) into nitrogen and water.

The challenge: Ammonia slip
To achieve high NOₓ conversion rates, ammonia is frequently dosed in slight excess. This can lead to residual ammonia ("ammonia slip”) leaving the SCR stage unreacted.

The solution: PrimePurity ASC
The PrimePurity catalyst is installed directly downstream of the SCR reactor. It selectively oxidizes residual ammonia, ensuring clean exhaust gas and enabling reliable compliance with environmental regulations.

Chemical Reaction

On the catalyst surface, ammonia is converted into the main natural components of air:

4 NH₃ + 3 O₂ → 2 N₂ + 6 H₂O 

This reaction removes toxic and odorous ammonia and transforms it into environmentally benign products.

Summary

With PrimePurity as part of the DeNOx+ concept, P&P Industries provides a fully integrated solution combining:

- High-efficiency NOₓ reduction (SCR / DeNOx)

- Reliable ammonia slip removal (ASC)

- Additional conversion of CO and VOCs (depending on configuration)

This ensures maximum environmental compliance, operational safety, and optimized overall system performance.