The main purpose of biomass drying is evaporation of water to reduce its moisture-to-dry matter ratio. This reduction of moisture is beneficial in a number of ways. Low water content in biomass intended for energy applications, such as heating and power cogeneration greatly increases fuel efficiency, lowers emissions and improves overall process equipment operation. In agriculture, post-harvest drying is essential for safe and long term storage of some product groups, such as grains. Drying the organic waste and other organic by-products results in substantial reduction of weight, which lowers treatment and storage cost, as well as encourages novel uses of the biomass, e.g. pelletizing and fertilizers.
Further positive economical and environmental effects can be achieved when combining drying process with the use of residual or waste heat from CHP and biogas power plants, as well as from other thermal energy intensive industrial operations.