VERFAHREN ZUR WIEDERGEWINNUNG VON KOHLENDIOXID

摘要

A method for recovering substantially all carbon dioxide generated in a combustion process where the method comprises the following steps: a) a sweep gas is used to pick up oxygen on the permeate side of a mixed conducting membrane in a first stage which is capable of separating oxygen from a hot air stream fed to the retentate side of the membrane; b) the sweep gas containing oxygen is applied as oxidant in a combuster in the first stage where a carbon containing fuel is combusted; c) hot combustion products of step b) containing CO2, H2O and a low concentration of O2 is used as sweep gas in a membrane in a second stage downstream the combuster in step b); d) the concentration of oxygen in the sweep gas of step c) is increased in the membrane in the second stage (step c) to a sufficiently high level to be used as oxidant in the combuster in the second stage; e) and the steps c)-d) are repeated in one or more stages. Furthermore, the present invention relates to use of the method in different processes.