Dynamics of Two-Adsorbent Beds with Flow-Reversal for Gas Separation

Abstract

In industrial adsorption processes, beds packed with superposed layersof different adsorbents are currently used. This paper discussesthe advantages of this design, and illustrates some of the complexfront behaviours that may occur. A representation is introduced,where the propagation of some particular concentrations is shownas ''pseudo-characteristics'' in a distance-time diagram. This allowsa convenient visualization of front propagation as obtained froma computer simulation with a detailed model. The example used hereis hydrogen purification from a mixture with nitrogen, methane andcarbon dioxide, by pressure-swing adsorption.