A COMPARISON OF NUMERICAL-METHODS APPLIED TO NONLINEAR ADSORPTION COLUMNS

Eight numerical schemes (first-order upstream finite difference, MacCo rmack, explicit Taylor-Galerkin, random choice, flux-corrected transpo rt, ENO, TVD, and Euler-Lagrange methods) are compared on the basis of their computational efficiency for one-dimensional non-linear convect ion-diffusion problems. For the ideal chromatographic equation for whi ch an exact solution exists, errors plotted against computational time s show that the best methods are the random choice, Euler-Lagrange and flux-corrected MacCormack methods. Even when significant diffusion is added to the model, steep gradients are possible because of nonlinear ities. In such an instance, the random choice and flux-corrected trans port methods give the best performance. One can now tackle more compli cated problems and refer to this comparative study in order to choose an adequate numerical method which will provide sufficiently accurate results at a reasonable cost.