Nonlinear frequency response of nonisothermal adsorption systems

Abstract

A general method for the investigation of adsorption kinetics of nonlinear, nonisothermal systems, based on frequency response analysis, is presented. It is based on the definition of higher-order frequency response functions (FRFs) on the adsorber and on the particle level. FRFs on the adsorber level can be estimated from experimentally measured adsorber FR and used to calculate FRFs on the particle level, which can be further used for model identification, by comparison with theoretical particle FRFs. The general procedure for calculation of particle FRFs from those of adsorber is given. Also, the general procedure for theoretical derivation of particle FRFs is given and illustrated with an example of nonisothermal adsorption governed by micropore diffusion and film resistance heat transfer, as well as the procedure for calculating unmeasured adsorber FRFs, which is illustrated with an example of a batch adsorber with volume modulation.