Effect of heat transfer on the transient dynamics of temperature swing adsorption process

The effect of radial heat transfer on temperature swing adsorption (TSA) was studied by using an air-drying TSA experiment. The experimental dynamics of water adsorption and thermal regeneration in a fixed bed packed with zeolite 13X were used to evaluate the predicted results from the developed models. One- and two-dimensional models for energy balance with various equations describing internal velocity were compared in terms of the prediction of transient dynamics of TSA. Since the heat effect in adsorption step depended on the isosteric heat of adsorption, a dynamic simulation was performed under adiabatic, near-adiabatic, and constant wall temperature conditions. A comparison between one- and two-dimensional models was also made under near-adiabatic condition, which reflected on the experimental condition. There was little difference between adsorption breakthrough curves predicted by the one- and two-dimensional models because the radial distribution of temperature was negligible at the adsorption step. In the case of the regeneration step, a small difference between two models was expected just at the early period of time because the radial effect disappeared with time. One-dimensional model could provide an adequate prediction of the transient dynamics in this system when the wall energy balance was included.