Abstract

A model to take into account the finite exchange kinetic for the equilibrium between phases in the chromatography experiment is studied. The resulting hyperbolic system with a nonlinear relaxation term is then formally treated with a Chapman-Enskog type expansion. A first order correction to the classical quasilinear hyperbolic model is derived which. consists of a nonlinear diffusion term. Numerical schemes for both models - relaxed and parabolic - are then rested and compared for different initial and boundary values. A range of validity for the first order approximation is obtained through numerical simulations where its computational performance indicates that it should be advantageously used. (C) 2000 Elsevier Science B.V. All rights reserved.