ANALYSIS OF THE FREQUENCY-RESPONSE METHOD APPLIED TO NONISOTHERMAL SORPTION STUDIES

A model describing non-isothermal sorption of gases within sorbent mat erial with a monodisperse pore structure, in a batch frequency respons e system, subjected to small periodic volume perturbations is formulat ed. The model accounts for internal mass diffusion resistance, surface mass transfer resistance, external film heat transfer resistance, and heat transfer to the surrounding environment. The general model is li nearised and analytical solutions for the in-phase and out-of-phase co mponents of the gas temperature and pressure response and the sorbent particle temperature response to a harmonic perturbation of the system volume are presented for infinite slab, infinite cylinder and spheric al microparticle geometry. Finite rates of heat transfer from the gas phase to the environment and from the sorbent particle to the gas phas e are shown to influence significantly the in-phase and out-of-phase c omponents of the gas pressure response.