As a response to the Texas State Implementation Plan to attain the ozone standard in the Houston-Galveston area, Texas Genco installed selective catalytic reduction (SCR) systems on their coal-fired and some of their gas-fired power generating units within this area. During 2003, SCRs were placed in service at Texas Genco's coal-fired W.A. Parish Units 5, 6, and 8 as well as gas-fired units at Cedar Bayou (Unit 2) and P.H. Robinson (Unit 4). This paper will describe the tuning, commissioning, and operational challenges encountered by Texas Genco during startup and initial operation of these new NO{sub}x reduction systems. All of these SCRs experienced relatively trouble free startups and all have subsequently passed their respective NO{sub}x reduction efficiency, NH{sub}3 slip, and SO{sub}2 to SO{sub}3 oxidation guarantees. This paper will describe some of the key design features that led to these successful startups and early operation. Some minor problems associated with dilution air fans, in-situ NO{sub}x analyzers, sonic horns operation, and most recently AIG pluggage had to be addressed for coal-fired units. For the gas-fired units, the response of SCR system at the lower load and lower temperatures at full load created problems. Texas Genco is currently addressing these issues and does not foresee them to be a long-term problem.
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