Method for separating gases in an oxy-fuel combustion process by using oxygen-permeable membranes

A process to selectively generate and separate gases, comprising:

• a first step in which a gas-phase fuel stream and an oxygen rich input stream are passed through a first oxygen separation ceramic membrane module, wherein the gas-fuel stream comprises combustible substances whose oxidation gives rise to gaseous products, the oxygen rich input stream is either water vapor or a portion of an oxygen-depleted stream from a second oxygen separation ceramic membrane module, and the gas-phase fuel stream and the oxygen rich input stream come into contact through a first membrane, a heat exchange takes place between them, and a partially oxidized combustible gas stream is output,
• a second step of selective oxygen diffusion in which the partially oxidized combustible gas stream from the first oxygen separation ceramic membrane module and the water vapor are passed through the second oxygen separation ceramic membrane module, such that the output streams from the second oxygen separation ceramic member module are, on the one hand, an oxygen-depleted or completely oxygen-free stream and, on the other hand, a partially oxidized or completely oxidized stream, and
• a third step of recovery in which a third oxygen separation ceramic membrane module receives the oxygen-depleted stream from the second oxygen separation ceramic membrane module to extract oxygen such that one of at least two separate outlet streams of at least two gases is oxygen and another of the at least two separate outlet streams is selected from nitrogen, carbon dioxide and hydrogen.