WHAT DOES THE TERM DESICCANT MEAN?
Desiccation refers to the state of extreme dryness, or the process of extreme drying. A desiccant is a substance that absorbs or adsorbs water. It is most commonly used to remove humidity that would normally degrade or even destroy products sensitive to moisture. Silica gel, calcium sulfate, montmorillonite clay, and molecular sieves are commonly used as desiccants. Desiccants are also used to dry solvents, typically used for moisture free reactions. While different desiccants are used differently, the general method involves stirring the solvent to be dried with the drying agent. Usually, the drying agent will react with moisture to form a solid insoluble in the solvent being purified. It can be removed simply by filtering. For more demanding applications, requiring very pure, air-free and/or moisture free solvents, a distillation still used with a desiccant able to remove air, moisture, and other impurities all at once.
