No More Breaks!

Get continuous NOx Emissions Control during the 20-minute CEMs calibration.

24/7 NOx Emissions Control

Global ROC helped a Combined Cycle Power Plant in Indiana stay within their NOx 3.0 ppm limit.

The Challenge

The customer’s current CEM’s system to monitor the NOx emissions would go offline 20 minutes every day exposing the customer to potentially going out of compliance, monetary fines, and potentially losing their permit. The customer’s NOx has a 3.0 ppm limit.

Our Solution

NH3 Regression Curve – A Control System Logic Add-On

Easy to install

Quick to implement


Project Results

Ultimately, the installed NH3 Regression Curve controlled stack NOx on all 4 units between 2.0 and 2.8 ppm. The following actions were performed without an exceedance of NOx emissions:

Duct Burners were placed into and out of operation on all four units.

All four Gas Turbines changed MW’s on Automatic Generator Control (AGC) from base load to 130 MW several times.

Performance mode was changed on all four GTs.

CEMs calibration on all four units.


Global ROC installed the regression curves on all 4 units which were controlled by the regression curve for a total of 28 hours:

(4 hours and then 24 continuous hours.)

Discover how Global ROC can help save you money and time by implementing the NH3 Regression Curve – A Control System Logic Add-On