A device used to reduce the moisture from a solid material. The most common type involves the passing of heated air with a low humidity over the moisture-bearing solid, thereby causing evaporation and removal of the moisture. The drying process is carried out until a desired moisture content is achieved. Other types of batch dryer include the use of desiccant and hygroscopic materials, which absorb the moisture from the air causing a drying effect of the material to be dried. Refrigerated dryers use a reduced temperature form of moisture removal, while membrane dryers use a semi-permeable membrane to remove moisture.