During solvent removal, energy is applied as heat such that the liquid is vaporized to gas, which is removed to leave a concentrated or solvent-free (dry) product. Many systems are referred to generically as “evaporators.” However, true evaporation is vaporization to gas at the liquid surface; for many “evaporators” boiling occurs rather than evaporation.

Solvent removal is an essential process across a broad range of applications in the pharmaceutical, chemical, and biotechnology industries. Although a diversity of sample formats and solvents are used, no single solvent removal technique provides a universal solution. Various commercial evaporation and concentration systems have been developed to accommodate the range of application.

A relatively recent application is in the so-called Zero Liquid Discharge technology, where plants are engineered to reduce to a minimum, possibly to zero, all emissions of pollutants or wastewater streams.