Fixed Bed Gas Adsorbers are used to separate gas species from a mixture of gases. They are constituted by a shell containing a fixed bed of adsorbent particles. The gas pass through the adsorbent bed where the target gas species is adsorbed in the adsorbent particles.
According to the species' molecular characteristics to be separated and affinity for the adsorbent material, they can be operate under high pressure (Pressure Swing Adsorber - PSA), near-atmospheric pressure (Vacuum Swing Adsorber - VSA), at the lowest temperature which avoids condensation (Temperature Swing Adsorption - TSA) or combination of both pressure and temperature.
Specific adsorptive materials are used to adsorb the target gas species which are typically activated carbon, silica gel, alumina, resin and zeolite.
Adsorbent Particles have finite capacity for gas phase molecules. An extended contact with the feed gas will ultimately lead to the saturation of the solid adsorbent which induce the need of either to regenerate the adsorbent or to dispose of it.
In Pressure Swing Adsorber, the process swings from high pressure to low pressure to desorb the adsorbed material when the bed has to be regenerated while in Vacuum Swing Adsorber, the process swings from near-atmospheric pressure to a vacuum to desorb the adsorbed material. In Temperature Swing Adsorption, the process swings from the lowest temperature which avoids condensation to high temperature to desorb the adsorbed material.