Modeling and analysis of dynamic adsorption during gas transport through a membrane

A mathematical model was developed to describe dynamic adsorption during mass transfer of a gas across a membrane based on the Langmuir adsorption theory. A dimensionless variable, B = bD(m)W(max)/delta K-a, which reflects the degree of non-equilibrium adsorption in the membrane, was used to characterize the membrane transport. Simulations considered the mass transfer during moisture exchange across a membrane. The results show that with a mass flux across a membrane, the deviation of the adsorption at the membrane surface from the equilibrium adsorption is mainly characterized by B. This dynamic adsorption increases the mass transfer resistance. As the membrane thickness approaches zero, this additional resistance dominates the total resistance. (C) 2009 Elsevier B.V. All rights reserved.