Carbon membrane gas separation of binary CO2 mixtures at high pressure

• We investigated the performance of carbon membranes for pressures up to 20 MPa.
• Flux and selectivity are examined for equimolar binary mixtures.
• The studied temperature range is 300–450 K.
• This research covers mixtures of Carbon Dioxide, Oxigen, Nitrogen and Helium.
• Maxwell–Stefan diffusion has been applied to study the mass transport.

The key feature of inorganic membranes is the ability to operate at high temperature and pressure. Even supercritical solvents can be processed by these membranes, whereas polymer membranes tend to swell and consequently suffer from reduced selectivity and mechanical strength. The combination of chemical and mechanical stability of ceramic membranes opens completely new fields of applications, e.g. in membrane reactors for chemical reactions like H2-synthesis by dehydrogenation. This work investigates the selectivity and permeance of carbon membranes for binary mixtures composed of Helium, Nitrogen, Oxygen or Carbon dioxide in a pressure region up to 20 MPa and a temperature range from 300 to 450 K. A Maxwell–Stefan diffusion approach has been applied to study the gas to gas and gas to membrane interactions under high pressure condition.