Desiccants are adsorbent materials used to remove water vapour and other contaminants.
A desiccant is a hygroscopic substance that creates or sustains a state of dryness (desiccation) in its vicinity. Commonly encountered pre-packaged desiccants are solids that adsorb water. Desiccants for specialised purposes may be in forms other than beads. These may include pellets and powders. They work by principles such as chemical bonding of water molecules. They are commonly encountered industrially were they are widely used to control the level of water in gas streams and products.
There are a number of desiccant refills that are available in standard pack sizes of 1kg. These desiccants include molecular sieves, non-indicating silica gel, indicating silica gel, activated alumina and activated carbon.