Qualitative Characterization of the Pellet Obtained from Hazelnut and Olive Tree Pruning

Abstract

Biomass occupies a very important place among renewable energy sources, and the residual biomass recovery chain represents a sector of fundamental importance. Our work focused on the production of pellets by pruning residues from two of the most important woody crops in Italy: hazelnut and olive groves. We found a higher value of bulk density for the hazelnut pellet (581.30 kg m−3 vs. 562.38 kg m−3) and a higher value of length for the olive pellet (16.66 mm vs. 10.47 mm). The percentages of durability were very similar (98%). The low heating value and ash content of hazelnut and olive were 17.21 MJ kg−1 and 3.1%, and 16.83 MJ kg−1 and 2.5%. A higher concentration of Cu, Pb, and Ni was observed in the hazelnut. The contrary was observed for the concentration of Zn. N content was 0.77% and 1.24% for the hazelnut and the olive, respectively. The concentration of S was 0.00% for both. The quality parameters that do not meet current standards could be improved by mixing these materials with different types of wood.

Effects of composts obtained from hazelnut wastes on the cultivation of pepper (Capsicum annuum) seedlings

“…In the last few years, hazelnut wastes have been studied to derive value from the production of medicinal mushrooms, biopellet production, etc. 5 , 6 . Composting is another way to add value to them.…”

Eco-Efficiency of Pellet Production from Dedicated Poplar Plantations

“…Despite being an important renewable energy resource, whether derived from dedicated energy crops or not, it is widely recognised that woody biomass is characterised by low energy density, high moisture content, heterogeneous geographical distribution and high transport costs that limit its wider use as an energy source [11][12][13]. These drawbacks can be overcome by applying a process of densification, or rather pelletisation, to the source woody material, which optimises the use of this solid biofuel as an energy feedstock [14][15][16][17][18], improving storage and facilitating the logistics and supply of power plants and small individual boiler rooms [19][20][21].…”

“…The pellet, therefore, comes in a cylindrical form with a diameter of 6-8 mm and an average length of 10-12 mm, which is easy to package and use [24,25]. The starting woody material can be represented by residues from wood processing (sawdust), by wood chips obtained from residues of treetops and forest branches, or even materials derived from the use of dedicated energy systems (SRC) or by residues of agroforestry pruning [9,18,[26][27][28][29]. Naturally, the transition from raw wood material to pellets involves a production process consisting of several steps that necessarily increases the cost of the finished product.…”

Comparison of energy properties of pellets from shells of different nut species

“…An example is an Italian study that assessed the energy performance of pellets made from hazelnuts and olives obtained by pruning on local farms. The research showed a slight deterioration in the quality of the produced pellets, and further research was proposed to determine the appropriate ratio of the given materials with clean sawdust (Acampora et al 2021). It is also possible to press waste shells into larger forms, which was effectively demonstrated in one Indonesian study using local cashew nut shells waste to make briquettes (Ifa et al 2020).…”