Ammonia Injection Grid (AIG)

Ammonia Injection Grid (AIG)

  • Conceptual Design
  • Post-Installation Tuning and Optimization
  • Experienced field personnel and training capabilities
  • No horizontal vanes - often the root cause of ash fallout and pluggage issues on the catalyst
  • Provides optimum delivery of NH3 to treat NOx

A well-designed ammonia injection grid is the backbone of an efficient SCR.


An AIG is a device used with SCR systems. Specifically, the AIG is used as an input device for ammonia that will react with NOx in the reactor. AIGs can be designed for either anhydrous or aqueous ammonia (NH3) systems. Depending on the customer’s objectives, AIGs can range in complexity from a single injection point to hundreds of injection points which are independent and controllable.

Fuel Tech’s scope of supply to AIGs includes: conceptual and detail design, engineering, fabrication, and delivery. Fuel Tech begins with basic unit information such as the ammonia (NH3) delivery rate specified by the catalyst vendor and customer objectives and constraints, then proceeds through a step wise procedure to provide the most cost effective and efficient delivery system possible. The design is tested and optimized using Computational Fluid Dynamics (CFD) and experimental (physical) fluid dynamics scale modeling.