Desorber

A desorber is a vessel used to remove adsorbed or absorbed species from a solid or liquid phase, typically as part of an adsorption-desorption cycle. In industrial practice, desorbers regenerate adsorbents such as activated carbon, zeolites, or ion-exchange resins by desorbing the accumulated contaminant and preparing the sorbent for another cycle.

Desorption is achieved by applying heat, changing pressure, or contacting the sorbent with a desorbing solvent. Thermal desorption uses elevated temperature to overcome adsorption forces; steam or hot inert gas can carry away the desorbed species. Solvent desorption uses a miscible liquid to dissolve the adsorbate and transport it to a recovery step. In many systems, the desorber operates in conjunction with a condenser or stripper to separate and recover the desorbed material.

Common configurations include steam-stripping desorbers for volatile organic compounds, hot-gas desorbers for carbon beds, and solvent-based desorbers used with resins in various industrial processes. The equipment is often a fixed-bed or moving-bed vessel equipped with heating, insulation, and a means to remove the desorbed stream (gas, steam, or liquid solvent). Energy efficiency is pursued through heat integration with the adsorption stage.

Applications span air and water treatment (removal of volatile organic compounds and solvents), gas separation (regeneration of adsorbents in pressure swing or temperature swing processes), and hydrometallurgical operations such as desorption of metals from ion-exchange resins or carbon. The design and operating conditions depend on the sorbent material, the nature of the adsorbate, and the desired purity of the desorbed stream.