Development of a Pelleting Machine for Hazelnut Residue Utilization

This study evaluates the technical and environmental aspects of hazelnut production wastes for energy utilization. A commercial- as well as a laboratory-scale pelleting machine were developed and tested for hazelnut residues utilization. The residues 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 proper ties (bulk density, pellet density. mechanical duration and pellet firm ness, and pellet moisture and equivalent humidity contents), and thermal properties (gas emission values after combustion, ash content and calorific values) of the pellets were mea sured. Pellet bulk densities varied between 541.2 kg/m(3) and 587.9 kg/m(3), while the pellet densities varied between 1,238.2 kg/m(3) and 1,309.4 kg/m(3). Mechanical durability (MD) values varied from 89.6% to 93.3%. Firmness values changed from 1146 N to 1574.2 N. Ash content was 7.2% and heating value of the pellets was 18.4 MJ/kg. The effect of material moisture content and particle size on the parameters was found to be statistically significant. In conclusion, hazelnut husk agricultural residue was found to be suitable as a solid biofuel in the form of pellets, for both in environmental and in fuel properties aspects.