Global ROC Enhances NH3 Injection System for a Power Generation Company in Texas

The Challenge

A Power Generation Company faced a unique challenge with its ammonia injection system, tasked with controlling for NOx pounds/Megawatt (NOxLbs/Mw).

Unlike the industry norm of controlling stack NOx emissions, the site aimed for the much tighter range of 0.12 NOxLbs/Mw, with a compliance limit of 0.14.

The existing manual operation during power transitions often pushed the unit to the brink of non-compliance.

ammonia injection system
ammonia injection valve during power transitions

Our Solution

Global ROC introduced a tailored solution with a custom logic block. This block rapidly adjusted the ammonia injection valve during power transitions, akin to a feed-forward option on a PID controller. Uniquely, the added value was immediately removed, enabling the standard ammonia valve controller to bring NOx back to the desired setpoint within seconds.

This innovative approach allowed the site to maintain automatic mode during both steady-state and megawatt transitions, preventing compliance issues and NOx alarms.

Custom logic block

Project Results


The implementation of the custom logic block yielded significant results:

Precise Control: Tight control over NOxLbs/Mw during both steady-state and power transitions.

Continuous Compliance: Automatic mode operation without triggering NOx alarms, even during dynamic megawatt changes.


Global ROC meticulously designed and integrated the custom logic block, ensuring seamless and precise control over the ammonia injection system.

Explore how Global ROC’s tailored solutions can elevate your emission control strategies. Achieve precision, continuous compliance, and operational ease. Take the first step toward optimized emission control – Learn more about our innovative solutions today.