In 2014, a pilot pellet plant designed for olive pulp pomace, located in Yeri Municipality, near the city of Nicosia was designed and commissioned with grants awared by the Cross-border Cooperation Program “Greece-Cyprus 2007-2013” (Interreg) entitled ”Design and development of collection, management and distribution centers for the exploitation of olive solid waste energy purpose” (link). The pilot plant covers a total fenced area of 150 sq, meters and consists of a typical rectangular-shape masonry building with a total area of 48 sq. meters which is used for the protection of the olive husk dryer. The unit consists of a feeding silo, a drier, a milling machine, a cyclone, a pelleting machine and a weighing and packaging assembly. The unit was designed for olive pomace, but it can also be used for other agro-residues.

A brief descritpion of the operation principles of the pelleting unit are provided:

• The raw material is manually fed into a small silo connected to a grid-powered screw conveyor, and it is mechanically transported to the inlet port of the dryer which has a maximum drying capacity of 250 kg olive husk per hour. Pre-dried olive pomace is also burned in a combustion chamber to satisfy the energy demand of the drying process. Heat transfer from the boiler to the continuous conveyor belt system is achieved using heat exchangers. The exhaust gases and vapours are mechanically vented to the environment through a cyclone and an installed duct system. 

• The dried olive pomace is collected at the bottom end of the dryer and is automatically fed to the RS 650, 7.5 kW grid-connected milling machine. The main parts of the milling machine are the machine frame and engine assembly, and the cutting and crushing rotor assembly. Eighteen (18) cutting knives are used for the milling of dried olive husk giving a capacity of 100-500 kg h-1 depending on the sieves used (4-25 mm). For the purposes of this study, a 4 mm sieve was used and a capacity of 150 kg h-1 was achieved. 

• The crushed, dried olive husk is transferred by compressed air to a collection tank with a total capacity of 300 lt which is connected to a 2.5 kW cyclone for the separation of the finest particles. 

• The grinded material is manually transferred to the AMP360c rotating roller pelletizing machine which is powered by a 22 kW 3-phase motor. The diameter of the produced pellets is 6 mm and a maximum capacity of 500 kg h-1 can be achieved based on the processed feedstock and the feeding rate which can be adjusted. The produced pellets are finally transferred to a silo using a perforated belt conveyor which allows the simultaneous cooling and dust removal from the produced pellets. 

• The collection silo is connected to the weighing and packaging assembly which delivers the final, tradable product. 

The following table provides information regarding the installed and operating pellet production equipment of the olive husk pellet plant.(click to enlarge).

 

Media Presentation of Peletting Center at Yeri Municipality link

TV short documentary film, Cyprus Broadcasting Center (CyBC) (Σπίτι στη φύση, 29/11/2015), link