Sorption Process

Sorption is a physical and chemical process by which a substance (typically a gas or liquid) accumulates within another phase or on the phase boundary of two phases. Depending on the place of accumulation, a differentiation is made between absorption (accumulation in a phase) and adsorption (accumulation at the phase boundary).

The reverse process is called desorption.

Sorption processes can be investigated by Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) and Evolved Gas Analysis (EGA).

The figure below shows two sorption-desorption cycles on a zeolite sample. The zeolite sample was treated with atmospheric cycles between wet and dry nitrogen gas flows. During the injection of a wet gas flow, the sample exhibits a distinct mass increase which is a result of the water absorption within the zeolite network, whereas during the dry gas flow, desorption takes place. The graph presented shows that the water absorption of a zeolite is a totally reversible process.

Two sorption-desorption cycles on a zeolite sample

Related Methods

TGADSC

EGA