ALBERT

Description: The valorization of agricultural residues plays a fundamental role in renewable energy production. Particularly, the management of olive orchards in Lazio region generates a considerable amount of biomass that is currently unexploited, but it could represent a valid source of solid biofuel for energy production in the Lazio region (Italy). Using a Geographic Information System (GIS) approach entirely based on open source software, five suitable areas (A, B, C, D and E) have been selected as eligible for hosting and feeding a 1 MWe power plant. Harvesting and transportation costs were also calculated. The harvesting operation costs were EUR 96.79 Mgfm−1 in A, while they ranged from EUR 49.83 Mgfm−1 (E) up to EUR 56.51 Mgfm−1 (D) for the other sub-areas. Sub-area A showed also higher transport costs, EUR 21.55 Mgfm−1 while the same value ranged from EUR 14.75 Mgfm−1 (E) to EUR 16.59 Mgfm−1 (B) in the other sub-areas. However harvesting costs resulted higher than those reported in the literature, mainly due to the low pruning yield per surface unit, an aspect which is directly related to the olive grove’s management in the region where annual pruning is the usual practice. Future developments of the present study should encompass the social and environmental aspects of residual biomass supply chains herein proposed.

Description: The collection of residues from staple crop may contribute to meet EU regulations in renewable energy production without harming soil quality. At a global scale, chaff may have great potential to be used as a bioenergy source. However, chaff is not usually collected, and its loss can consist of up to one-fifth of the residual biomass harvestable. In the present work, a spreader able to manage the chaff (either spreading [SPR] on the soil aside to the straw swath or admixed [ADM] with the straw) at varying threshing conditions (with either 1 or 2 threshing rotors [1R and 2R, respectively] in the combine, which affects the mean length of the straw pieces). The fractions of the biomass available in field (grain, chaff, straw, and stubble) were measured, along with the performances of both grain harvesting and baling operations. Admixing chaff allowed for a slightly higher amount of straw fresh weight baled compared to SPR (+336 kg straw ha−1), but such result was not evident on a dry weight basis. At the one time, admixing chaff reduced the material capacity of the combine by 12.9%. Using 2R compared to 1R strongly reduced the length of the straw pieces, and increased the bale unit weight; however, it reduced the field efficiency of the grain harvesting operations by 11.9%. On average, the straw loss did not vary by the treatments applied and was 44% of the total residues available (computed excluding the stubble). In conclusion, admixing of chaff with straw is an option to increase the residues collected without compromising grain harvesting and straw baling efficiencies; in addition, it can reduce the energy needs for the bale logistics. According to the present data, improving the chaff collection can allow halving the loss of residues. However, further studies are needed to optimise both the chaff and the straw recoveries.

Description: In cereal crops, chaff is a valuable lignocellulosic by-product that accounts for more than 50 Mt y−1 in Europe and is suitable for bioenergy purposes. Chaff is usually not collected due to the lack of combine harvesters that have the capability to handle it properly. The present two years experimental study investigated the hypothesis that the overall biomass collected in wheat crop can be increased by equipping the combine harvester with an aftermarket device. Chaff, discharged from the combine harvester-cleaning system, is collected by the turbine that delivers it either on the swath or on a lateral trailer towed by a tractor. The performance of all machines involved in the harvesting (combine harvester, tractor, baler, and trailer) were assessed. The chaff was collected in bales with the straw (A mode) and separately on a trailer (C mode). Comparisons with non-collected treatment (B mode) were performed in order to estimate the total chaff collected and the biomass losses. The results showed that 1.79 t FM ha−1 per year of chaff could be collected when baled with the straw, whereas 1.27 t FM ha−1 were collected separately on a trailer. Both field and material capacity were not negatively affected by the chaff collection. Therefore, our study confirmed the hypothesis that turbine technology is a valid solution for increasing the total residual biomass collected in cereal cropping for energy purposes.

Description: Reducing potential soil damage due to the passing of forest machinery is a key issue in sustainable forest management. Limiting soil compaction has a significant positive impact on forest soil. With this in mind, the aim of this work was the application of precision forestry tools, namely the Global Navigation Satellite System (GNSS) and Geographic Information System (GIS), to improve forwarding operations in hilly areas, thereby reducing the soil surface impacted. Three different forest study areas located on the slopes of Mount Amiata (Tuscany, Italy) were analyzed. Extraction operations were carried out using a John Deere 1410D forwarder. The study was conducted in chestnut (Castanea sativa Mill.) coppice, and two coniferous stands: black pine (Pinus nigra Arn.) and Monterey pine (Pinus radiata D. Don). The first stage of this work consisted of field surveys collecting data concerning new strip roads prepared by the forwarder operator to extract all the wood material from the forest areas. These new strip roads were detected using a GNSS system: specifically, a Trimble Juno Sb handheld data collector. The accumulated field data were recorded in GIS Software Quantum GIS 2.18, allowing the creation of strip road shapefiles followed by a calculation of the soil surface impacted during the extraction operation. In the second phase, various GIS tools were used to define a preliminary strip road network, developed to minimize impact on the surface, and, therefore, environmental disturbance. The results obtained showed the efficiency of precision forestry tools to improve forwarding operations. This electronic component, integrated with the on-board GNSS and GIS systems of the forwarder, could assure that the machine only followed the previously-planned strip roads, leading to a considerable reduction of the soil compaction and topsoil disturbances. The use of such tool can also minimize the risks of accidents in hilly areas operations, thus allowing more sustainable forest operations under all the three pillars of sustainability (economy, environment and society).

Description: Forest and agricultural biomass are important sources of renewable and sustainable fuel for energy production. Their increasing consumption is mainly related to the increase in global energy demand and fossil fuel prices but also to the limited availability of petroleum and the lower environmental impact of these biomass compared with other non-renewable fuels. In particular, the pellet sector has seen important developments in terms of both production and the number of installed transformation plants. In addition, pellet production from non-woody biomass is increasing in importance. One of the fundamental aspects for the correct and sustainable use of a biofuel is evaluation of its quality. This is even more important when dealing with pellet production, considering the broad spectrum of possible raw materials for pelletizing. Considering the significant number of papers dealing with pellet quality evaluation and improvement in the last decade, this review aims to give the reader an overall view of the most current knowledge about this large and interesting topic. We focused on pellets of agricultural and forestry origin and analyzed papers regarding the specific topic of pellet quality evaluation and improvement from the last five years (2016–2020). In particular, the review findings are presented in the following order: the influence of different agro-forest management systems on pellet quality; analysis of pellets from pure feedstocks (no blending or binders); the influence of blending and binders on pellet quality; and the influence of pre and post treatments. Finally, a brief discussion about actual research lacks in this topic and the possibilities for future research are presented. It is important to underline that the present review is focused on the influence of the biomass characteristics on pellet quality. The effects of the process parameters (die temperature, applied pressure, holding time) on pellet features are not considered in this review, because that is another very large topic deserving a dedicated paper.

Description: The sustainable production of renewable energy is a key topic on the European community’s agenda in the next decades. The use of residuals from agriculture could not be enough to meet the growing demand for energy, and the contribution of vegetable oil to biodiesel production may be important. Moreover, vegetable oil can surrogate petroleum products in many cases, as in cosmetics, biopolymers, or lubricants production. However, the cultivation of oil crops for the mere production of industrial oil would arise concerns on competition for land use between food and non-food crops. Additionally, the economic sustainability is not always guaranteed, since the mechanical harvesting, in some cases, is still far from acceptable. Therefore, it is difficult to plan the future strategy on bioproducts production from oil crops if the actual feasibility to harvest the seeds is still almost unknown. With the present review, the authors aim to provide a comprehensive overview on the state of the art of mechanical harvesting in seven herbaceous oil crops, namely: sunflower (Heliantus annuus L.), canola (Brassica napus L.), cardoon (Cynara cardunculus L.), camelina (Camelina sativa (L.) Crantz), safflower (Carthamus tinctorius L.), crambe (Crambe abyssinica R. E. Fr.), and castor bean (Ricinus communis L.). The review underlines that the mechanical harvesting of sunflower, canola and cardoon seeds is performed relying on specific devices that perform effectively with a minimum seed loss. Crambe and safflower seeds can be harvested through a combine harvester equipped with a header for cereals. On the other hand, camelina and castor crops still lack the reliable implementation on combine harvesters. Some attempts have been performed to harvest camelina and castor while using a cereal header and a maize header, respectively, but the actual effectiveness of both strategies is still unknown.

Description: The growing population worldwide will create the demand for higher cereal production, in order to meet the food need of both humans and animals in the future. Consequently, the quantity of crop by-products produced by cereal cropping will increase accordingly, providing a good opportunity for fostering the development of the sustainable supply chain of renewable solid fuels and natural feedstock for animal farming. The conventional machineries used in wheat harvesting do not guarantee the possibility to collect the chaff as additional residue to the straw. The present study investigated the possibility to equip a conventional combine with a specific device, already available on the market, in order to collect the chaff either separately (onto a trailer), or together with the straw (baled). The total residual biomass increased by 0.84 t·ha−1 and 0.80 t·ha−1 respectively, without negatively affecting the performance of the combine when the chaff was discharged on the swath. Farmers can benefit economically from the extra biomass collected, although a proper sizing of the machine chain is fundamental to avoid by-product losses and lower revenue.

Description: Among the species currently cultivated for industrial vegetable oil production, castor could be a good candidate for future investments due to the good resistance to pests, tolerance to drought, and suitability for marginal lands cultivation. In addition, the production of castor oil from Ricinus generates a large quantity of press cake, husks, and crop residues that, in a framework of bioeconomy, could be used as by-products for different purposes. Using a case study approach, the work presents results of the environmental impact assessment and economic feasibility of the production of castor oil from two different castor hybrids comparing four by-products management scenarios and two harvesting systems (manual vs. mechanical). Castor hybrid C-856 harvested manually and that involved only the soil incorporation of press cake obtained by the oil extraction resulted as the most sustainable. The hybrid C-1030 resulted as more profitable than C-856 when harvested with the combine harvester. The ratio between gross margin and GWP emissions was applied to calculate the economic performance (gross margin) per unit of environmental burden. Findings showed that Sc1B scenario in case of C-856 cultivar hybrid had a better ratio between economic performance and greenhouse gas (GHG) emitted into the atmosphere (€3.75 per kg CO2eq).

Description: Camelina is a low input crop than can be cultivated in rotation with cereals to provide vegetable oil suitable for bioenergy production, industrial applications and even as source of food for livestock. At large scale farming, camelina seeds are currently harvested using a combine harvester, equipped with a cereal header, but the literature still lacks the knowledge of the performance of the machine, the harvesting cost and the related loss of seeds. The present study aims to fulfill that gap by reporting the results obtained from an ad hoc harvest field test. Camelina seed yield was 0.95 Mg ha−1 which accounted for the 18.60% of the total above ground biomass. Theoretical field capacity, effective field capacity and field efficiency were 3.38 ha h−1, 3.17 ha h−1 and 93.7% respectively, albeit the seed loss was 80.1 kg ha−1 FM (7.82% w/w of the potential seed yield). The presence of material other than grain was rather high, 31.77% w/w, which implies a second step of cleaning to avoid undesired modification of the seed quality. Harvesting cost was estimated in 65.97 € ha−1. Our findings provide evidence on the suitability to use a conventional combine harvester equipped with a cereal header for the harvesting of camelina seeds, although some improvements are required to reduce both seed loss and impurities.