Patent ID: 6966190

Claim:
A combined cycle process for generating electric power that includes: 1) a steam turbine train comprised of one or more steam turbines in series that has an upstream high pressure steam inlet and a downstream exhaust steam outlet, and that drives an electric generator, 2) two or more gas turbines in parallel that each drive an electric generator, 3) a heat recovery unit, and 4) a gasification plant that produces a fuel gas stream selected from low BTU gas and mid BTU gas from a hydrocarbon containing material, the combined cycle process comprising the steps of: a. firing fuel gas in the gas turbines to drive their electric generator to produce electric power and emit a gas turbine combustion exhaust gas stream from the fired gas turbines; b. feeding a high pressure superheated steam stream to the upstream steam inlet to the steam turbine train and withdrawing a low pressure steam stream from the downstream steam outlet on the steam turbine train to produce electric power with the steam turbine train generator; c. condensing the low pressure steam stream from the steam turbine train to form a condensate stream; d. conveying the condensate stream to the heat recovery unit wherein the condensate stream is heated to form the high pressure super heated steam stream that is fed into the upstream steam inlet of the steam turbine train; e. combining the gas turbine exhaust gas streams and conveying the combined gas turbine combustion exhaust gas stream to the heat recovery unit wherein sensible heat is transferred from the combined gas turbine combustion gas stream to the condensate stream to convert the condensate stream to the high pressure superheated steam stream that is fed into the high pressure steam inlet to the steam turbine train; f. injecting the fuel gas that is produced in the gasification unit into the gas turbine combustion exhaust gas stream flowing through the heat recovery unit at a plurality of points spaced along the direction of flow of the combustion exhaust gas stream in the heat recovery unit.