High pressure adsorption, permeation and swelling of carbon membranes – Measurements and modelling at up to 20 MPa

Abstract

A unique 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. Carbon membranes open new possibilities, e.g. the processing of high pressure, high temperature fluid streams directly in place or the use in membrane reactors for chemical reactions like H2-synthesis by dehydrogenation. This work investigates high pressure adsorption of carbon membrane material for different gases at up to 12MPa, the selectivity and permeance for CO2/N2 mixtures in a pressure range from 0.1 to 20MPa and the swelling of carbon material exposed to Oxygen at up to 10MPa. A model based on Maxwell-Stefan diffusion with parameters gained from measured adsorption and fluxes has been implemented to improve the understanding of the behaviour of high pressure separation with carbon membranes.