Applications of non-linear frequency response for investigation of adsorption systems

Abstract

Two main directions of application of nonlinear frequency response and the concept of higher order frequency response functions (FRFs) in investigation of adsorption systems are presented, one for development of novel methods for investigation of equilibrium and kinetics of adsorption systems, and the other for fast estimation of periodic steady-states of cyclic adsorption processes. The main advantages of the nonlinear FR methods for estimation of adsorption equilibrium and kinetics are: (1) It is possible to discriminate between different kinetic mechanisms and to select the correct one from the shapes of the second and higher order FRFs. (2) Both equilibrium and kinetic parameters can be estimated from the FRFs. Different experimental arrangements are presented. Estimation of periodic steady-states of cyclic adsorption processes is illustrated on the example of periodic operation of an adsorption column with modulation of the inlet concentration and the column temperature.