Observations and Effects of Load Cycling and Reserve Shutdowns on Long-Term SCR Catalyst Management

摘要

A major shift has occurred for coal plant operations due to reduced demand, low natural gas prices, and increases in wind and solar generation, resulting in frequent load cycling and reserve outages. This paper's objective is to assess trends and impacts of this operations shift on SCR system operation and catalyst management. Reduced low load operation targets have made it increasingly difficult to assure reliable SCR system operation. This has presented challenges for ammonia injection while preserving catalyst performance. Persistent load cycling, reserve shutdowns, and the migration through dew point temperatures have resulted in new catalyst deactivation trends for both bituminous and PRB fired units. As such, the new plant operations paradigm has resulted in new and differing trends of catalyst deactivation and strains to accommodate new low load objectives. Recent experience and results will be presented to better assure reliable SCR operations, risk management, and accurate budget planning efforts.