2nd Generation PFB Plant With W501G Gas Turbine
Research has been conducted under United States Department of Energy (USDOE) Contract DE-AC21-86MC21023 to develop a new type of coal-fired, combined cycle, gas turbine-steam turbine plant for electric power generation. This new type of plant — called a 2nd Generation or Advanced Pressurized Fluidized Bed Combustion (APFB) plant — offers the promise of efficiencies greater than 48 percent (HHV) with both emissions and a cost of electricity that are significantly lower than those of conventional pulverized-coal-fired plants with scrubbers. In the 2nd Generation PFB plant coal is partially gasified in a pressurized fluidized bed reactor to produce a coal derived syngas and a char residue. The syngas fuels the gas turbine and the char fuels a pressurized circulating fluidized bed (PCFB) boiler that powers the steam turbine and supplies hot vitiated air for the combustion of the syngas. A conceptual design and an economic analysis was previously prepared for this plant, all based on the use of a Siemens Westinghouse W501F gas turbine with projected gasifier, PCFB boiler, and gas turbine topping combustor performance data. Having tested these components at a pilot plant scale and observed better than expected performance, the referenced conceptual design has been updated to reflect that test experience and to incorporate more advanced turbines e.g. a Siemens Westinghouse W501G gas turbine and a 2400 psig/1050°F/1050°F/2-1/2 in. Hg steam turbine. This paper presents the performance and economics of the updated plant design along with data on some alternative plant arrangements.