The ISA77.82 Subcommittee is working on a standard for selective catalytic reduction (SCR) control systems. The subcommittee typically meets three times a year, in February at ISA Headquarters, in June at the ISA POWID Symposium, and at the ISA Fall Automation Week. The latest draft standard and meeting minutes are downloadable from this site.
The standard ANSI/ISA-77.82.01-2011, Selective Catalytic Reduction (SCR) Control Systems, was recently approved and published.
- Cyrus Taft
This standard will address the control functions associated with the selective catalytic reduction systems on fossil fired steam boilers greater than 200,000 lbs/hr and combustion turbines greater than 25 megawatts. This includes the outlet NOx control using ammonia flow control, startup and shutdown logic, bypass/isolation logic, dilution air system control, ammonia storage and delivery system control, and catalyst cleaning systems. Urea to ammonia systems are excluded from the scope of this document.
The purpose of this standard is to establish the minimum design requirements for the functional design specifications of selective catalytic reduction control systems for use in fossil fired power plants.