Rapid Thermal Swing Adsorption

This article presents a new rapid thermal swing adsorption process. It is based on a composite adsorbent bed, composed of an arrangement of layers of activated carbon particles separated by sheets of a highly conductive graphite material. It also uses thermoelectric devices (Peltier elements) to alternatively heat and cool the adsorbent bed. The high effective conductivity of the bed and the fast dynamics of the thermoelectric elements allows cycles (cooling and adsorption/heating and desorption) to be run in 10−20 min. The operation is illustrated experimentally with the uptake and concentration of carbon dioxide from a helium flow. A model is developed that accounts for the usual mechanisms of equilibrium and heat- and mass-transfer kinetics in adsorption, coupled with the specific dynamic behavior of the thermoelectric elements.