Development of a Pelleting Machine for Hazelnut Residue Utilization

This study evaluates the technical and environmental aspects of hazelnutproduction wastes for energy utilization. A commercial- as well as a laboratory-scalepelleting machine were developed and tested for hazelnut residues utilization. Theresidues were pelleted at two different moisture contents (M10: 8%-10% and M12:10%-12%) as referred to EU standards, and particle sizes (PS: 6 mm and 10 mm).Physical properties (bulk density, pellet density, mechanical duration andpellet firmness, and pellet moisture and equivalent humidity contents), andthermal properties (gas emission values after combustion, ash content andcalorific values) of the pellets were measured. Pellet bulk densities varied between541.2 kg/m3 and 587.9 kg/m3, while the pellet densitiesvaried between 1,238.2 kg/m3 and 1,309.4 kg/m3.Mechanical durability (MD) values varied from 89.6% to 93.3%. Firmness valueschanged from 1146 N to 1574.2 N. Ash content was 7.2% and heating value of thepellets was 18.4 MJ/kg. The effect of material moisture content and particlesize on the parameters was found to be statistically significant. Inconclusion, hazelnut husk agricultural residue was found to be suitable as asolid biofuel in the form of pellets, for both in environmental and in fuelproperties aspects.