• Energy Research

Hemp is among the oldest plants known in traditional medicine and one of the most phytochemically studied. The psychoactive phytocannabinoid in acid form (THCA) is most concentrated in the inflorescences. During harvesting and cleaning of the seeds, there could be contamination with parts of the plant containing THCA, and therefore there could also be this metabolite in the oil, which could undergo the process of decarboxylation to become psychoactive THC. The aim of this study was to identify the levels of THC present in hemp seed oil of the Uso-31 variety extracted by cold pressing at two different temperatures (40°C and 70°C) and at two different pressures using the diameter nozzles of (8mm and 12mm). The experimental field was divided into eight plots cultivated with different agronomic practices in order to evaluate the influence of these on the amount of THC. Chemical analysis of the oil showed a THC presence of less than 5 mg/Kg. Proceedings of the 30th European Biomass Conference and Exhibition, 9-12 May 2022, Online, pp. 273-278

Mechanical harvesting of hemp seeds is performed using machines developed for other grain crops in order to allow an easier insertion of hemp cultivation into consolidated production area trying to avoid further purchase of complex and expensive machinery on the territory. On the other hand, it involves the use of machines with low harvesting efficiency because the hemp plants are considerably different from the cereal grain plant having a biomass production 2-3 times bigger than grain in weight. However, hemp seed is harvested when the seed begin to scatter. All these factors combined, lead to a complex setting of the combine harvester. In this paper, harvesting tests were performed in order to evaluate the efficiency of mechanical harvesting of hemp seeds with conventional combine harvester with cereal head, some harvest tests were carried out by varying only the machine setting without significant modifications of the machine. The experimental design included the division of the field into 4 plots, cultivated with a seeding density D1 (60 pt / m2) and D2 (30 pt / m2). Only two plots received foliar fertilization. Each plot has been divided sub-parcels collected with two working speeds of the machine: V1 (3 kmh-1) and V2 (5 kmh-1). The combination of plots configuration provided 8 experimental. The total seed yield per m2 has been obtained hand-picking the seeds in experimental plots divided by agronomic pre-treatments and then cleaned. The harvest efficiency has been calculated comparing the total seed yield with the mechanical seed harvesting using different settings of combine harvester. This work showed an average harvesting efficiency of 68%. Higher efficiency percentage has been obtained on plots with 60 plants/m2 density and harvested at V1 speed. This experience has highlighted some limitations due to the general use of non-specific hemp solutions for harvest, but this result can be explained with different cultivation techniques of hemp. Proceedings of the 26th European Biomass Conference and Exhibition, 14-17 May 2018, Copenhagen, Denmark, pp. 374-377

The aim of the study is to evaluate the possibility of two step harvesting system for giant reed. The biomass was shredded and dried in the field, in second time was baled and storage. First step was cutting and shredding with a specific shredder for biomass crops rear mounted in agricultural tractor and in the second time the Arundo biomass was harvested after more day of drying in the field with continuous monitoring of the biomass moisture content. This harvesting system presents some advantages such as: the possibility of long storage of biomass (moisture content lover 14-15%), baled with a farm mechanization for hay making, possibilities of diversified use of the dried biomass (combustion and II generation ethanol). The test showed technical and energy aspect of the harvest technology but there is necessary one specific machine for shredder while the other are normally presents in the farm. The machine adopted for shredder, designed and developed by Italian constructor for more biomass herbaceous crops (Arundo, Sorghum, Panicum, Mischantus, etc..) is indicated for high vegetative developed crop and can spread the product in all soil surface or windrowing. The tests were conducted in the South of Italy (Campania region) in an experimental farm of Torrelama. The tests have showed a good performance slightly lower than 1.5 ha h-1 (1.47) with operative speed of 4.88 km h-1. The hourly production is 58.35 t ha-1 with a biomass moisture content of 42.51%. After field drying the biomass are baled and storage. Proceedings of the 26th European Biomass Conference and Exhibition, 14-17 May 2018, Copenhagen, Denmark, pp. 305-308

Short-rotation coppice (SRC) represents an important source of wood biomass. Many uncertainties create barriers to farmers establishing SRC plantations, especially under Mediterranean climate conditions. In this study, five species and respective genotypes were analyzed. The five species were Fraxinus angustifolia, Robinia pseudoacacia, Salix alba, Populus nigra (Limatola), and Populus × euroamericana, with the genotypes of the latter being Grimminge, Vesten, Hoogvorst, Muur. For the plantations studied, two different harvesting systems were replicated: the single machine pass, or cut-and-chip (CC); and the double machine pass, for which the tree are cut first, then chipped later (chip of stored trees CS). In the CC, fresh trees were harvested and chipped by Claas Jaguar 880. In the CS, dry trees were chipped by Farmi Forest CH 260. Within the same site, in climatic conditions and low-input management, the best result in terms of biomass yield was obtained from the black poplar Limatola. Both wood typologies and harvesting systems affected the chip quality. The disk chipper, when working on dried biomass, produced lower quality chips than the other chipping device in terms of particle size. In the chips obtained, there was an increase in the number of chips classified as being “larger size” and “oversized”, and a decrease in the percentage of those classified as “accept” (45–3 mm fraction). The chips obtained from dried trees were of better energy quality compared with the same biomass obtained from the fresh trees in terms of heating value and ash content.

Fast growing trees planted as Short Rotation Coppice (SRC) are an important source of lignocellulosic biomass, due to their high yields, good combustion quality, ecological and social benefits and relatively low production costs. The quality and the price of the biomass are determined by its particle size distribution, heating value, moisture and ash content. These parameters can vary significantly as a function of the wood species and the time between the cutting phase and the chipping phase.In 2015, the Department of Agriculture of the University of Naples Federico II and the Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria (Crea), carried out some tests to identify the characteristics of the chips in eight different species grown as SRC, chipped after two months of storage: Fraxinus angustifolia, Robinia pseudoacacia, Salix alba, Populus nigra (Limatola) and four genotypes of Populus x euroamericana (Grimminge, Vesten, Hoogvorst, Muur). The average moisture content of the species was 29.30%, with an average heating value and ash content of 21.77 MJ kg-1 and 2.02%, respectively. These values differ among the various species and genotypes considered. The particle size distribution analysis revealed, instead, that independently from the species, the most represented class size was 45 to 3 mm. The variability observed in terms of dried biomass quality suggest the possibility to identify the species more suitable for the biomass combustion analyzing the mainly quality parameters, choosing the best species or different species mix wood chips to offer a better product in the commercial biomass marketing. Proceedings of the 26th European Biomass Conference and Exhibition, 14-17 May 2018, Copenhagen, Denmark, pp. 342-345