The Cool Water Coal Gasification Project requires a gas turbine combustion system to burn a high hydrogen medium-Btu coal gas produced in an oxygen-blown gasifier. The gas turbine selected for this demonstration plant is a General Electric Company MS7001E unit. The plant is located in Daggett, California, a location requiring compliance with stringent environmental regulations; that is, oxides of nitrogen (NOx) at 63.5 kg/hr and carbon monoxide (CO) at 35.0 kg/hr in the machine exhaust.
The plant operating configuration requires fuel gas to be supplied at 330 °K and 477 °K with 20%/vol moisture blended. A combustion system was developed enabling the gas turbine to operate from full speed no load to full load on both fuel gas configurations. Distillate oil capability was also incorporated to facilitate safe machine startup and shutdown.
Emissions requirements for NOx were met with steam injection, “CO” by combustor design, and sulfur oxides are met by fuel gas cleanup.
A conventional combustion liner sleeve with a standard air admission schedule was used. A unique fuel nozzle, based upon past low-Btu fuel work, was designed incorporating the latest low erosion oil nozzle.
One combustor of the 10 fitted to an MS7001E was tested at full pressure and airflow. Test results indicate, as predicted analytically, that NOx prediction varies substantially between cold dry fuel gas and hot wet gas. NOx compliance was attainable with little degradation of other design considerations. Carbon monoxide emissions were well below the required limits.