Selective catalytic reduction (SCR) systems utilizing a 32.5 percent liquid urea solution as the reagent were used for a temporary rental application for the first time, says Nationwide Boiler Inc., Fremont, Calif. Until the recent rental application, anhydrous ammonia, a chemical with stringent HAZMAT handling requirements, has been the standard reagent for rentals.

The rental project required two trailer-mounted 99 million BTU/hr saturated steam boilers. A second project required six trailer-mounted 99 million BTU/hr superheated steam boilers. A ground-mounted SCR system utilizing urea as the reagent was supplied for each boiler. In total, Nationwide Boiler provided eight urea-based SCR systems.

Nationwide Boiler Inc. has provided systems utilizing a urea solution (more commonly diesel exhaust fluid, or DEF), for stationary equipment for some time. The DEF systems have been added to the fleet of temporary process equipment offered for lease by Nationwide.