Nationwide Boiler Inc. says it recently supplied the first-ever temporary selective catalytic reduction (SCR) systems utilizing a 32.5% liquid urea solution, commonly known as DEF (diesel exhaust fluid), as the reagent.

Although the company has provided urea-based systems for stationary equipment for nearly eight years, this was a first for a temporary rental application. Anhydrous ammonia, a chemical with stringent HAZMAT handling requirements, has been the standard reagent for rentals.

“This is a big step in our industry,” said Sean McMenamin, Nationwide Boiler’s director of environmental solutions. “Until now, ammonia was the common reagent utilized for a temporary SCR application. We often found that the strict handling requirements associated with the use of ammonia would hinder our ability to provide an SCR on certain job sites. We have now built an inventory of urea skids and associated ductwork required for these rental systems. This allows us to provide a safe alternative for customers adverse to ammonia handling requirements.”

The first rental project required two trailer-mounted 99mbtuh saturated steam boilers, while the second project required six trailer-mounted 99mbtuh superheated steam boilers. A ground-mounted CataStak™ SCR system, utilizing urea as the reagent, was supplied for each boiler. In total, Nationwide Boiler provided eight urea-based CataStak SCR systems, all of which achieved less than 5ppm vd at 3 percent O2 NOx outlet levels.