PARADIGMS AND PARADOXES IN MODELING ADSORPTION AND CHROMATOGRAPHIC SEPARATIONS

Modern approaches to modeling adsorption and chromatographic operations rely, implicitly or explicitly, on a restricted number of ''paradigms'', such as the equilibrium-stage approach and the theoretical plate, the kinematic wave, the constant pattern, the Langmuir isotherm, and a few others. Their role in organizing knowledge and experience in adsorption research is considerable, and the set of currently used paradigms expresses the state of mind, the ''dominant ideology'' in the field at a given instant. The present communication proposes a nonexhaustive inventory of these paradigms, analyzes their origin and their scientific supports, and discusses their role in the progress of the field, their conservative function, and their contribution to strengthening the concerned community or to opening it to others. Illustrations are given that paradigms are sometimes paradoxes, and finally, a discussion of the missing paradigms is proposed, i.e., paradigms which have not yet been established or recognized, but which may be the keys to future progress.