Numerical analysis on gas separator with thermal transpiration in micro channels

Abstract

A gas separator that can induce a large variation of mole fraction by a small temperature difference in a single membrane is proposed. The separator makes use of two effects: The first effect is the thermal transpiration through microchannels in the membrane; the second is the accumulation of the effect of micro-channels in the counter flow of gas mixture that flows around the membrane. The numerical results show that small gas separation effects of numerous micro-channels are accumulated to induce a large variation of the mole fraction along the membrane. The numerical calculation is carried out by the direct simulation Monte Carlo (DSMC) method and a fluid model based on the mass conservation which is shown to be able to simulate the DSMC result. The performance of the device is investigated for several temperature differences between the two sides of the membrane. The relation to the membrane gas separation by Knudsen diffusion is also discussed.