The Turbine Talk: One-on-one with Environex at AMC 2026

Environex + Hanwha Power: What Happens Downstream When You Lower Inlet NOx

Most conversations about combustion upgrades stop at the turbine. This one keeps going. Andrew Toback, Principal Engineer at Environex, sits down with Marc Babine, Shaftline Engineer at Hanwha Power, to talk about something that often gets overlooked in the upgrade decision: what a reduction in inlet NOx actually does to the SCR and CO catalyst systems sitting downstream.

Environex has spent 30 years managing industrial catalyst systems for power generation facilities, and their position as an independent specialist, not tied to any catalyst manufacturer, gives them a clear-eyed view of how these systems perform in the field. Their work with Hanwha Power's customers connects directly to one of the more practical questions plant operators face after a combustion retrofit: does the work you just did on the turbine affect what you need to do on the catalyst?

The short answer is yes, and in this conversation, the details are worth understanding:

• Longer catalyst useful life: Lower inlet NOx means the SCR catalyst is working less hard, which extends the period before performance drops below acceptable thresholds.
• Reduced reagent consumption: Less NOx to process means less ammonia or urea required, with direct operational cost implications.
• Decreased salt formation on the economizer: A chemistry benefit that affects heat transfer performance and maintenance frequency downstream of the SCR.

The conversation addresses both ends of the installed base. For plants running catalyst systems installed between 2001 and 2010, the calculus around a combustion upgrade looks different than it does for newer installations, and Toback draws on case studies and actual plant operating data to walk through both scenarios.

For any plant operator who has gone through a combustion retrofit or is evaluating one, this is a concrete look at the downstream benefits that rarely get quantified during the upgrade decision.