NONLINEAR FREQUENCY-RESPONSE OF ADSORPTION SYSTEMS - ISOTHERMAL BATCHAND CONTINUOUS-FLOW ADSORBERS

The problem of nonlinear frequency response of adsorption systems is t reated using the concept of higher-order frequency response functions (FRFs). The FRFs on the adsorber and on the particle scale are conside red. Based on nonlinear mathematical models, expressions that correlat e the higher-order FRFs of isothermal batch and flow adsorbers and the FRFs on the particle scale are derived. In the batch adsorber, there are two sources of nonlinearity: one associated with the reservoir, an d the other with the adsorption process, while in the flow adsorber th e nonlinearity is due to nonlinear adsorption process only. Applicatio n of the method is illustrated on the example of adsorption governed b y Langmuir kinetics. The higher order FRFs on a particle and on an ads orber scale are simulated, as well as the nonlinear FR of the adsorber s. (C) 1998 Elsevier Science Ltd. All rights reserved.