Selection of Sorbents for Gas Phase Adsorption. For gas phase adsorption processes it is almost always necessary to select a suitable sorbent by experiment, i.e. a sorbent that is suitable for adsorption as well as for desorption. Therefore sorbents from the group of activated carbons, adsorbent resins and zeolites have been tested and compared with each other under adsorption and desorption conditions. The sorbents have also been checked for reliable function. Operational disturbances are often caused by components such as water vapor or (irreversibly adsorbing) high boiling components. In any case it is useful to select adsorbents which are not susceptible to interference by these components. The co-adsorption of water vapor, undesirable in practice, normally leads to a reduced adsorbent capacity. It is also shown that a single high boiling component, present in traces-in the gas, loads the adsorbent to the same extent as the pure-main component, so that there is hardly any capacity left for the main component. The range of investigation was insufficient to draw up general rules for the different groups of sorbents referring to the points considered.