Patent ID: 7947115

Claim:
An integrated gasification combined cycle system, comprising: an ion transport membrane air separation unit for producing oxygen-enriched gas and oxygen-depleted air; a gasification system for generating syngas from a carbonaceous fuel reacting with the oxygen-enriched gas; a gas combustor for reacting the syngas; and a subsystem, configured to provide a first portion of a first stream of air to the air separation unit at a first pressure and to provide a second stream of air to the combustor at a second pressure lower than the first pressure, the subsystem comprising an air turbine connected to receive a second portion of the first stream of air from which the second stream of air is provided and to deliver the second stream of compressed air to the combustor; and an air chest for mixing the oxygen-depleted air and the second stream of air to provide an air mixture, wherein the air separation unit is configured in the system to deliver the oxygen-depleted air to the air chest.