Abstract: The present invention relates to a method for removing and recovering CO2 from exhaust gas from a gas turbine based electric power and heat generation process (a main power process) by chemical absorption and desorption for deposition of CO2 as convenient at the location. The exhaust gas from said main power process is cooled before being fed to a secondary gas turbine based power and heat generation process (a secondary power process) where said exhaust gas is compressed to elevated pressure and used as oxidant in a secondary gas turbine combustion chamber in said secondary power process. The resulting hot exhaust gas from said secondary process is further fed to a turbine connected to an electric power generator where the exhaust gas is depressurised to close to ambient pressure before entering a heat recovery process where the exhaust gas is cooled and further fed to a CO2 separation process for capturing of CO2.

Abstract: A method for operating one or more electrolysis cells (43, 154, 243) for production of aluminium, the cell comprising inert or substantially inert anodes, where an oxygen containing gas (21, 126, 221) evolved by the electrolysis process in the cell is gathered and removed therefrom. The oxygen containing gas is introduced into a combustion chamber (38, 149, 238) where it is reacted with a carbon containing gas (7, 116, 209) in a combustion process. Emisions of CO2 and NOx can be reduced.

Abstract: The invention concerns a method of operating a combustion plant comprising at least a first gas turbine (26), a second turbine (34, 50) and a membrane reactor device (16) which comprises a membrane filter device (18) for separating oxygen from a gas mixture and a combustion space (19). A gas mixture containing oxygen is supplied to the membrane reactor device (16). At least some oxygen is separated from the gas mixture with the help of the membrane filter device (18). The separated oxygen is used at the combustion in the combustion space (19). The oxygen-depleted gas that is obtained after the separation of oxygen and which has not gone through a combustion process is used to run the first gas turbine (26). Combustion gases run the second turbine (34, 50). The invention also concerns a combustion plant for carrying out the method.