Patent ID: 8778054

Claim:
A method for generating heat energy in a power plant by burning a carbonaceous fuel in a combustion chamber of the power plant in which the combustion chamber is provided with an atmosphere including a gas mixture of oxygen and cleansed heated flue gas, the method comprising the steps of: (a) creating a gas mixture of cleansed heated flue gas and oxygen in a membrane chamber; (b) supplying the gas mixture from the membrane chamber to the combustion chamber; (c) supplying a carbonaceous fuel to the combustion chamber; (d) burning the carbonaceous fuel in the combustion chamber in the presence of the gas mixture; (e) creating the gas mixture by (1) adding heated fresh air at a pressure not exceeding 2 bars to a membrane chamber on a retentate side of a membrane present in the membrane chamber, the heated fresh air being at a temperature corresponding to an operating temperature of the membrane, the operating temperature of the membrane being in the range of 600° C. to 1000° C., whereby oxygen in the heated fresh air passes to a permeate side of the membrane and a resulting oxygen-depleted exhaust air is removed from the retentate side of the membrane chamber, and (2) introducing the cleansed heated flue gas to the permeate side of the membrane, whereby the oxygen on the permeate side of the membrane mixes with the cleansed heated flue gas and the gas mixture is created; (f) preparing the cleansed heated flue gas by (1) cooling flue gas produced by the burning of the carbonaceous fuel in the combustion chamber to provide cooled flue gas and cleansing the cooled flue gas to provide cleansed cooled flue gas and (2) heating the cleansed cooled flue gas to provide the heated cleansed flue gas, the heated cleansed flue gas being heated to a temperature corresponding to the operating, temperature of the membrane, the cleansed heated flue gas being introduced to the permeate side of the membrane as indicated in step (e)(2): wherein the aforedescribed method steps are run continuously for a selected amount of time.