Combined cycle power plant incorporating atmospheric circulating fluidized bed boiler and gasifier

Claim 1

In a combined cycle power generation system, having a fluidized bed boiler for combusting solid fuels to produce steam and a heated exhaust output, a hot separator for separating particulates from the heated exhaust output and returning the particulates to the fluidized bed boiler via a hot separator return path, a steam turbine powered by steam produced in the fluidized bed boiler and a gas turbine powered by heated compressed air, the improvement comprising: an air compressor for providing a source of compressed air to the gas turbine; a recuperator connected to said air compressor and to an exhaust output from the gas turbine for heating the compressed air to a first temperature prior to input to the gas turbine; an external bed air heater connected to said recuperator and to the hot separator return path for heating the compressed air fluid to a second temperature prior to input to the gas turbine; a gas turbine combustor connected to said external bed air heater and to the gas turbine for heating the compressed air to a third temperature prior to input to the gas turbine; a first fuel source including natural gas connected to the gas turbine combustor for providing fuel to the gas turbine combustor; and a second fuel source including coal gas fuel connected to the gas turbine combustor for providing fuel to the gas turbine combustor.