Optimal energy management in grain drying

The energy required for drying grain in the U.S. has significantly increased because a large proportion of corn is harvested at high moisture contents and represents a major portion of the energy utilized for all on‐farm grain‐processing operations. In general, about 25% of the total energy consumed for drying is lost through inefficient practices. The efforts to optimize grain‐drying energy requirements have resulted in significant modifications in existing dryer designs and the development of new design concepts. This paper presents a thorough review of current literature reporting on grain‐drying procedures such as high temperature drying, low or no heat drying, combination of high and low temperature drying, layer drying, drying intermittently with rest periods, cyclic drying, dryeration, recirculating the dryer exhaust air, stir drying, and use of grain preservatives. Drying with alternative energy sources such as solar and biomass energy and use of heat pumps are also reviewed. Application of computer controls for energy‐efficient drying is discussed. Emphasis of the review is placed on examining these drying procedures in light of their energy savings and adaptability. Quality of dried grain and overall system costs are also considered. Possible future options and trends are outlined.