Modeling of olive-oil mill waste rotary dryers: Green energy recovery systems

Olive-oil mill waste rotary dryers play an important role in the environmental protection and sustainable development in the olive sector. Drying of these wastes is vital for three main reasons: the extraction of olive oil contained in them (olive pomace oil) by the use of solvents, the obtaining of a biomass fuel called dry de-oiled pomace and the elimination of a highly polluting by-product due to its high biological oxygen demand (BOD). However, because of the transition from three-phase system to two-phase system, their drying presents serious problems due to high moisture contents and their nature and composition. The main objective of this work is to study and analyze the research carried out on drying kinetics of olive-oil mill wastes, which is vital to understanding the drying phenomenon, and on the main models of heat and mass transfer in the olive-oil mill waste rotary dryers, based mainly on the trommel and furnace. The synergy between these two general studies will serve as a starting point for improving the design and optimization of the drying process in this type of dryers.