Graycor Industrial Constructors recently completed work at Duke Energy’s new clean-coal integrated gasification combined cycle plant (IGCC) in Edwardsport, Indiana. This 618-megawatt power plant is the largest and most advanced commercial IGCC plant in the world. The plant converts locally-mined coal into a cleaner burning synthetic gas to power the first two gas turbines of its kind. When fully operational, the Edwardsport plant, which is slated to be a base-load station, will produce 70 percent less air pollution while generating 10 times the amount of electricity as the more than 60-year-old plant that it replaced. In addition to the coal-derived synthetic gas or “Syn Gas” being much cleaner than conventional coal combustion, coal gasification allows carbon capture to occur before the fuel is combusted.
This complex power project was completed in December of 2011 and represents the first new coal fired power plant constructed in Indiana in more than 20 years. It took 750 Graycor craftspeople during the time of peak labor power and over 1.9 million craft hours over a period of 3-1/2 years to complete the four separate packages within the scope of Graycor’s work. These packages included the complete coal handling system, the Power Block – Complete Pipe Rack and Steam Turbine Building, the Centerline Turbine Package and the Air Separation Unit Package. In total, all four packages included the installation of over 180,000 linear feet of pipe (including over 18,000 welds), 6,160 tons of steel and over 380 pieces of equipment set.
When the plant is fully operational, coal will be delivered to the site either via semi-trucks supplying an estimated 240 loads per day, or via trains carrying 75-100 full railcars and making deliveries 3-4 times per week. One component of Graycor’s work included construction of the coal handling system, which is necessary for conveying the estimated 1.7 to 1.9 million tons of coal used by the plant annually. Graycor’s work associated with the coal handling system included structural steel erection, complete unloading and conveyor equipment installation as well as complete mechanical piping and electrical scope installation.
Graycor’s work in the Power Block Area consisted of the Centerline Turbine Scope as well as the Complete Pipe Rack and Steam Turbine Building Installation. In addition to the two Combustion Turbine – Generator Sets, Graycor installed a Steam Turbine-Generator Set and all associated piping. In all, the Powerblock included over 130,000 linear feet of piping, 130 pieces of equipment, the complete steam turbine building installation and the complete installation of the semi-modularized pipe rack systems.
Lastly, the Air Separation Unit Package consisted of the complete above-foundation installation including multiple air compressor trains needed to generate oxygen for the gasification process and nitrogen integration with the gas turbines. This package included extensive mechanical equipment installations, complete piping system installations including insulation, complete electrical and controls installation, structural steel erection and multiple pre-engineered building erections.
This has been an important project for Graycor, not only because of its immense scale, but also because of the innovative gasified coal technology that has been integrated into the design of the Edwardsport plant. Although this technology has been used in chemical plants in the past, coal gasification technology that is used solely for producing electricity has only been utilized at 16 sites worldwide, making the Edwardsport plant one of the most sophisticated new projects in the power industry and helping to pave the way for the future of clean-coal technology.