Carbon Monoxide Emissions From Gas Turbines as Influenced by Ambient Temperature and Turbine Load

Abstract

The emissions of carbon monoxide (CO) from gas turbines are typically below 100 ppmvd at 15 percent O2 at design full-load operating conditions. The use of water/ steam to reduce NOx emissions from gas turbines results in an increase in CO emissions from gas turbines. This is particularly true when increased rates of water/ steam injection are used to meet stringent NOx limits. Regulations limiting CO emissions from stationary gas turbines were first initiated in the late 1980s by the Federal Republic of Germany and the state of New Jersey in the United States. Since these regulations are silent on ambient and load corrections, these CO limits could be the limiting factor in the current development of dry low-NOx combustion systems by gas turbine manufacturers. In addition, since manufacturers are usually quite specific regarding the conditions for CO guarantees, a conflict for the gas turbine user, who is responsible for the permit application, is readily apparent. This paper attempts to characterize the CO emissions from gas turbines as a function of ambient temperature and turbine load. An ambient temperature correction equation for CO emissions, based on previous work, is presented. The intent is to provide more extensive information on CO emissions such that better defined CO limits can be adopted. Ultimately, this should help the combustion design engineers in developing improved dry low-emissions combustion systems for the gas turbine industry.