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An experimental biofuel wood chip storage site was studied, as a potential fungal “reservoir,” by means of quantitative and qualitative assessments of airborne fungal spores. Fungal load in the bio-aerosol, determined through active and passive methods, declined with the distance from wood piles. Occupational exposure was comparatively evaluated when two specific operational tasks, manual and mechanized handling, were performed. Under the conditions tested, the manual operators were more exposed to the airborne fungal spores (4864 ± 580 CFU m−3 air). The collected spores were identified as belonging to species of the genera Alternaria, Aspergillus, Penicillium, Fusarium, Cladosporium, Pleospora, Cochliobolus, Epicoccum, Absidia, and Trichoderma. Most prevalent were the genera Alternaria and Cladosporium, with the highest percentages of occurrence (30 and 12%, respectively). To the best of our knowledge, this is the first work reporting the identification through molecular methods of airborne fungi released during the handling of wood chip biofuel biomass.

Poplar cultivation for wood/timber production has a growth production cycle of about 10-15 years. Usually the stem is separated from the crown and used to produce material of different kind such as veneer, pallets, panels, etc. For wood industries, crowns generally represent waste material to be disposed of, causing economic and time losses. It is generally believed that the costs of managing crown biomass are higher than the potential incomes obtainable. Nonetheless, it is worthwhile investigating the possibility of using these byproducts as energy source and evaluating their value as a fuel. However, storing such residues presents several problems connected with spontaneous microbial degradation. The aim of this work was to evaluate the storage effects on chipped biomass deriving from the crown and stem wood of poplar and how they affect fuel quality and dry matter losses.A storage trial was carried out with three piles of stem wood chips and three of crown chips coming from a 15 year old poplar plantation. The piles were stored outdoors for six months under the same climatic conditions. The effect of storage on fuel quality was evaluated with respect to moisture content, gross and net calorific values, chemical composition, ash content, and bulk density. The variation of temperatures inside each pile due to heat development was continuously monitored and showed different trends between piles depending on source material. Results showed that chips from crown material had better storage properties and exhibited lower decay than chips from stem wood. © 2014 Elsevier Ltd.

Research in anaerobic digestion of agricultural by-products has been introducing new and changing heavier fibrous energy-rich feedstocks that, when co-digested with manure, allow the enhancement of the biogas potential per m 3 of volatile solids but also induce significant changes in ingestate rheological properties (in comparison with raw manure). Doubts about the adequate level of amalgamation achievable by these mixtures inevitably arise. Because of the relationship between the total solids content and ingestate apparent viscosity, optimal mixing is not achieved only as consequence of the action of fermenter paddles and other stirring devices, but pumping devices also act positively on the way biomasses and manures are mixed. At up to 8% to 10% total solids, the high shear rates provided by centrifugal pumps (better if equipped with rotating knives) cause the manure-biomass mixture to behave like a Newtonian fluid. When the total solids percentage of the mixture exceeds this threshold, other pumping systems (lobe pumps as well as screw pumps) can provide adequate pressure to drive the mixture to the fermenter; however, in this case, further conditioning devices need to be considered to act positively on the anaerobic influent condition to improve its microbial degradation.

One of the main constraints hindering the cultivation of fiber sorghum, which produces a substantial amount of fermentable biomass, is the lack of an efficient harvesting method. The anatomical structure of the fiber sorghum plant makes conditioning the plants difficult, resulting in increased losses, diminished product quality, and increased harvesting costs. The purpose of this study is to investigate an alternate harvesting method to improve the shelf life of sorghum biomass and thereby reduce the costs of harvesting sorghum. A prototype of a rear tractor-mounted mower-conditioner was designed, built, and tested over two years (2007-2008). The machine was able to mow and vigorously condition each plant in separated single rows. The conditioner consisted of two counter-rotating rollers placed lengthwise in a forward direction, which fractured and crushed the stalks, providing a remarkable improvement in work quality compared with current methods. The prototype achieved a significant reduction in drying times compared to other systems and extended the harvest window, thus eliminating one of the main obstacles to a wider cultivation of fiber sorghum.

A commercial drum chipper was fed alternately and piecewise with poplar stems and poplar tops, in order to determine the effect of piece size and tree part on machine performance. Chipping stems required most of the available power (231 kW) delivered by the tractor, whereas chipping tops took about half that much. However, productivity was twice as high with stems, compared to tops (i.e. 25 and 11 t h-1 of oven dry wood, respectively). As a consequence, specific fuel consumption per unit product was 15% lower with stems, compared to tops - i.e. 0.61 and 0.72 L m-3, respectively. Mean feeding speed was 0.37 m s-1 for stems and 0.41 m s-1 for tops, but the difference was not significant (p = 0.1677). Productivity and fuel consumption were strongly related to piece size, but tree part had its own additional effect, independent from size and possibly related to form. When chipping tops it is advisable to feed more pieces at a time, in order to partly compensate for the effect of piece size. Operators expecting to chip primarily small-size materials may acquire special chipper versions with wider drums and additional side rollers, for smoother mass feeding. oThe same chipper was tested with poplar stems and tops.oChipping stems resulted in higher productivity and lower fuel consumption.oChipping stems required most of the available tractor power.oChip particle size distribution was about the same for both feedstocks. © 2013 Elsevier Ltd.

The authors tested six commercial pruning harvesters to determine harvesting losses and product contamination when recovering pruning residues from an overgrown olive orchard, typical of Southern Italy. All harvesters used a mechanical pick-up to collect the residues and a shredder to reduce them into chips. Three different pick-up settings were tested and namely: 1 cm above ground level, manufacturer's specification and 3 cm above ground level. Ash content in the shredded material was taken as a measure of contamination. The ash content of uncontaminated branch material collected directly from the trees was 3.5%. Ash content in shredded residues varied between 4.5% and over 5.5%, for the shortest and the longest distance between the pick-up and the soil surface, respectively. In contrast, harvesting losses were weakly (but significantly) related to pick-up setting, and mainly depended on machine type. © 2012 Elsevier Ltd.

Advanced Biofuels steadily developed during recent year, with several highly innovative processes and technologies explored at various scales: among these, lignocellulosic ethanol and CTO (Crude Tall Oil)-biofuel technologies already achieved early-commercial status, while hydrotreating of vegetable oils is today fully commercial, with almost 3.5 Mt/y installed capacity worldwide. In this context, microalgae grown in salt-water and arid areas represent a promising sustainable chain for advanced biofuel production but, at the same time, they also represent a considerable challenge. Processing microalgae in an economic way into a viable and sustainable liquid biofuel (a low-cost mass-product) is not trivial. So far, the most studied microalgae-based biofuel chain is composed by microorganism cultivation, lipid accumulation, oil extraction, co-product valorization, and algae oil conversion through conventional esterification into Fatty Acids Methyl Esters (FAME), i.e. Biodiesel, or Hydrotreated Esters and Fatty Acids (HEFA), the latter representing a very high quality drop-in biofuel (suitable either for road transport or for aviation). However, extracting the algae oil at low cost and industrial scale is not yet a mature process, and there is not yet industrial production of algae-biofuel from these two lipid-based chains. Another option can however be considered: processing the algae through dedicated thermochemical reactors into advanced biofuels, thus approaching the downstream processing of algae in a completely different way than separation. The present work examines the possible routes for thermochemical conversion of microalgae into liquid biofuels, distinguishing between dry-processes (namely Pyrolysis, PO) and wet-processes (near critical-water HydroThermal Liquefaction, HTL). A literature review on algae-HTL was carried out, distinguishing between batch and continuous experiments, and compared to original results from algae pyrolysis. In particular, pyrolysis was carried out on both starved (lipid-accumulated) and non-starved microalgae. Typical composition of major products is given for both PO and HTL, comparing the main characteristic of the products. Major engineering advantages and challenges in thermochemical conversion of algae into liquid biofuels were identified and discussed for both processes, in view of the production of a transport biofuel and the full exploitation of this renewable feedstock in energy and biorefinery complexes.

A continuous oxidative carbonization pilot unit, with a capacity of 50 kg/h,has been developed and builtby RE-CORD; reported performance data shows that the unit can produce high quality charcoal, suitable for BBQ, metallurgy of activated-carbon manufacturing, as well as biochar. Charcoal yield in excess of 24 wt% (dry) has been achieved, with a fixed carbon content higher than 85 wt% (dry). In this work,the up-scaled 250 kg/h demo plant has been designed, and the construction, operation and maintenancecosts estimated. It was assumed to feed the plant with a dedicated SRF of either poplar or robinia, which represents a very innovative and yet unexplored value chain. Performance data are reported along with economic evaluation of the whole chain. Results shows how aland management scheme based on SRF coupled to innovative small-scale biomass carbonization technology represents an appealing opportunity for business diversification in small and medium forestry enterprises.

International audience; AbstractKey messageMechanized cutting may result in higher stump damage levels, especially if cutting is performed with shears. Nevertheless, stumps cut with mechanized technology do not show higher mortality rates than do stumps cut manually with a chainsaw. One-year growth is also unaffected, and so is nutrient balance within the stump.ContextCoppice harvesting must be mechanized in order to modernize coppice management, so that it can grow along with the dynamic new bio-economy. However, foresters are concerned that mechanized cutting may result in higher stump damage levels, which may cause increased mortality and lower growth rates.AimsThe goal of the study was to compare manual and mechanized cutting in terms of cut quality, stump damage levels, stump mortality, re-sprouting vigor, and shoot growth.MethodsThe study was conducted in a classic Mediterranean coppice stand located in central Italy. The oak-dominated coppice was cut using a chainsaw (control), a disk saw and a shear. The experiment adopted a split-plot design, based on 5 plots divided into 15 subplots (1 subplot per plot and technology). Overall, 344 stumps were selected, tagged, and monitored over the first growing season after cutting. Stump size, cutting height, and cutting damage were determined right after cutting. At the end of the first growing season, the following parameters were also recorded: no. of shoots; height, diameter, and type of the tallest five shoots. Samples were collected from randomly selected stumps during the main phenological phases in order to determine the content of C, N, starch, and soluble sugar, as well as the C/N ratio.ResultsMortality ranged from 4 to 8%. Re-sprouting was generally vigorous, with dominant shoots often exceeding the height of 1.5 m after 1 year. Cutting technology had a significant effect on cutting height and cutting damage, but it had no effect on mortality, re-sprouting vigor, and nutrient balance within the stumps, at least in the first growing season. Re-sprouting vigor depended mainly on species.ConclusionWhile it may result in higher stump damage levels, mechanized cutting does not seem to have any effects on coppice regeneration and growth, at least in the first year. Previous studies indicate that effects recorded during the first growing season may be representative of longer-term trends. The experiment will be continued to obtain additional confirmation.

Industrial poplar plantations reach maturity in about 10–15 years, showing a wood productivity that is hardly achieved by other broadleaf species. Among the possible uses of this product, the energetic production is one of the most promising as it can offer additional revenues to plantation owners. However, the difficult handling and the large volumes occupied by crowns during storage decrease significantly the convenience of the recovery. Therefore, efficient and affordable storage methods need to be identified in order to make this product more manageable and profitable. The main goal of the research is to understand the dynamic of a long-term storage lasting 18 months and the effects of storage on fuel quality in both stem and crown of poplar chips. Storage performance were evaluated with respect to moisture content, dry matter losses, particle size distribution, bulk density, and fuel quality before and after storage. Contrary to the results obtained in Northern climates, this study revealed the poor storability of poplar chips, regardless the plant component (bole, branch, crown) considered, showing in the worse cases dry matter losses higher close to 50% and final moisture mass fraction increases to about 70%.

Four commercial harvesters were compared with respect to recovery of pruning residues for energy conversion. These harvesters were tested side-by-side on 17 test fields, totaling 15. ha. The test fields consisted of vineyards and apple and pear orchards. The residue yield was between 0.7 and 9 green tonne per hectare, at a moisture content from 37% to 48%. Yield was highest for the orchards, and lowest for vineyards. Harvesters collected the residues and moved them to the roadside at a cost of between 11 and 60EUR per green tonne, depending on field conditions and technology choice. Single-pass harvesting was the cheapest, especially if applied through a dedicated tractor and a towed unit with a large integral container. Two-pass harvesting was the most flexible, but also the most expensive: it should be favored only when space, weather or other management constraints limit the application of the other systems. © 2012 Elsevier Ltd.

Agroforestry practises can accrue significant benefits to farm owners and have a good potential for expansion worldwide. Among the many possible options, Black walnut plantations are especially popular in the Temperate zone, and are often based on the association with nurse trees, to be removed within the first two decades after establishment. The authors designed and tested two low-investment fully mechanized operations for producing chips or traditional firewood from the thinning of walnut plantations. The mechanized small-scale chipping operation incurred the lowest cost and offered a dramatic improvement over manual harvesting. On the other hand, mechanized firewood harvesting was financially less effective than traditional motor-manual operations. For the price levels assumed in this study, small-scale mechanized chipping offered higher profits than motor-manual firewood production all along the tree size range. Furthermore, chipping achieved a break even with smaller trees than firewood production, allowing for financially viable early thinning, timely performed before the nurse trees overtop the crop trees. © 2012 Elsevier Ltd. All rights reserved.

The oilseed rape is an interesting oil crop for energy production. In Italy there are many potential available areas for crop cultivation thanks to adequate rainfall and mild winters. The diffusion of rapeseed is restrained by the significant seed losses caused by mechanical harvesting and meteorological events. Aim of the study was to determine the effective seed losses taking into account all the phases of harvesting, from ripening to harvest, at on-farm scale. The combine used for mechanical harvester was equipped with two different header: a grain head and a specific oilseed rape head. The lost seed was collected by appropriate trays inserted between the crop rows on the ground, before and during the harvesting. The specific oilseed rape head permitted a general reduction of the seed losses, below the ranges reported in literature, and a more precise determination of the point where the losses were higher, as the terminus parts of the head.

The European Union issued an ambitious target for the introduction of biofuels in the transport sector: 10% by 2020. 2nd generation biofuels (e.g. BTL, lignocellulosic ethanol, algae) are expected to play an important role in the medium term: among these, lignocellulosic ethanol is a key technology currently under industrialisation. In the present work, second generation ethanol modelled through a process simulation developed in the software Aspen Plus® environment. A literature-based comparative analysis of the conversion technologies in terms of yield, efficiency, feedstock and level of process integration is carried out. Crucial aspects of the process include high pretreatment performances, efficient hexose and pentose fermentation, enzyme strain development and solid co-product valorisation for process heat and power generation. The investigated plant size processes 240,000 t biomass/y, with a production capacity of about 40,000 t ethanol/y. Ethanol productivity ranges between 303 and 316 l/t dry biomass. Considering a total energy input (chemical energy contained in the biomass fed to the process) of 108 MW, 36 MW of ethanol are obtained, and additional 2.5 MW of power: the net process energy efficiency is calculated in the range from 35% to 37%. Modelling was aimed to better understand the production process from poplar as feedstock and could be used to support process development in design and optimisation. In particular the lignin-rich residue thermal/chemical valorisation is a key issue that needs further studies, in order to improve the environmental and economic performances of the process.

In an attempt to perpetuate traditional forest management, the authors tested a new compact tractor designed to replace pack mules when harvesting firewood from Mediterranean coppice stands. The new machine was capable of replacing a standard eight-mule team, and small enough to use the same infrastructure. The main characteristics of the tractor were its narrow width, a shifting center of gravity and a capacity to unitize loads for more efficient handling. The tests showed that the new tractor can outperform an equivalent mule team under the same working conditions, doing the job without incurring a higher cost. Installing a remote control can enhance operator safety, and bring it to the same good levels achieved with animal extraction. Even if the new machine can fill the technical role of pack mules, it certainly cannot reflect the same cultural and historical value. This research was never spurred by the desire to replace draught animals, but rather by their rapidly declining numbers, and was undertaken with the purpose of preserving traditional coppice management. There is a cultural and ethical obligation to preserve animal logging, which can partly be obtained through optimized deployment, so as to increase animal logger revenues and provide them with a further motivation to stay in business. © 2011 Elsevier B.V.

The aim of this research work is to investigate the use of straight vegetable sunflower oil (SFO), a liquid biofuel, in a Micro-Gas Turbine (MGT). Compared to conventional diesel engines, micro-gas turbines represent a very reliable, clean and performing small scale cogeneration technology. Commercial gas turbines have already been tested with unconventional fuels, such as biomass derived fuels; however, research work on using Straight Vegetable Oil (SVO) as fuel in MGTs are really scarce. The chemical and physical characteristics of SVO are different from fossil diesel oil and rather far from the common technical specifications for gas turbine liquid fuels, not only in terms of kinematic viscosity and Lower Heating Value, but also as regards other issues as contaminant levels and composition, fuel cold properties, ignition properties, etc. Therefore, particular attention has to be given to the atomization and evaporation phases, as these are the most critical steps to achieve stable and efficient long term operation. An analysis based on numerical correlations available from literature was initially adopted for the analysis of the atomization process, supported by CFD modeling to qualitatively investigate the flow pattern. Control parameters were revised and set so to produce a sunflower oil spray having evaporation time comparable to diesel, and minor adaptations to the fuel line were designed and installed on the MGT. Tests with blends and straight vegetable oil were carried out to assess the difference between the standard and the modified machine, fed by diesel, in terms of exhaust emissions, power output and performances, that were similar to the standard diesel-fed MGT. Measured exhaust emissions were as expected well below those typical of diesel engines of the same size fed with VO. The experimental campaign confirmed that it is possible to operate a MGT fed with SVO through the adoption of minor modifications and by adjusting control parameters.

Vineyards cover about eight millions of hectares worldwide and their annual pruning generates a large amount of ligno-cellulosic biomass, potentially available for industrial and energy use. Commercial pruning residue harvesters are now available, which may allow cost-effective recovery. The study aimed at determining the quantity and the quality of pruning residues potentially derived from vineyard management. Data were obtained from 17 fields in Northern and Central Italy. Fields were harvested with seven different machines. The experimental design adapted to the necessities of field trials, but was adequate for testing the main sources of variability. Net residue yield varies around 1 oven dry tonne per hectare, with minor differences between grape varietals and harvesting technologies. Losses are still high, and are generally related to ineffective management techniques. Moisture content at harvest varies between 40% and 45%, whereas the higher heating value is slightly lower than that of forest fuels. Comminuted vineyard residues are unsuitable for firing residential boilers, due to the frequent presence of oversize and/or undersize particles. The application of pesticides does not result in any significant contamination with noxious chemicals, because these products are almost completely weathered before residues are recovered. In wine-producing regions, the recovery of vineyard pruning residue may represent a substantial source of industrial bio-fuel. © 2011 Elsevier Ltd.

The study compared the silvicultural results of individual tree selection as performed by licensed foresters, loggers, and licensed agronomists. The experiment was conducted on two tree marking training sites installed by the Regional Forest administration for Lombardy in the northern Italian mountains. Each site consisted of a 1.2-acre (0.5-ha) forest plot where all trees had been identified with painted numbers. Sixty-four volunteers were extracted from a larger pool representing licensed foresters, loggers, and licensed agronomists. Each volunteer was provided with simple paper forms on which he or she would note the identification number of each tree selected for removal. All volunteers were asked to apply the same silvicultural prescription. Statistical analysis of the results indicated no differences between the different professional groups. Most participants reached the prescribed percent removals and consistently selected the right tree size for two different silvicultural treatments. On the other hand, differences between single individuals were quite substantial, possibly reflecting different practical experience with tree marking. Overall, the study suggests that the quality of tree selection is not determined by the group an individual belongs to. Therefore, one may consider delegating tree selection to a properly trained logger, especially if the silvicultural prescription is relatively straightforward.

The Authors tested a complete new system for recovering wood fuel from the termination of depleted orchards. This operation can generate between 25 and 80 fresh t ha?¹, that can be directed to the growing bioenergy sector. The new system is based on highly-mobile low-investment general-purpose equipment, which allows containing operational cost and speeding relocation between work sites. The new residue collection system is quite flexible, and achieves cost-effective recovery on relatively small fields, often smaller than 1 ha. Under the conditions of the study, trees are cut, chipped and delivered at a cost between 35 and 40 EUR t?¹ (40% water mass fraction), provided that fields are within a 20 km distance from the biomass plant. Use of a standard drum chipper results in a better product quality than if a grinders is used, as is the case for conventional orchard removal operations. Feeding the chipper with a separate loader allows a significant cost reduction, provided that the field offers at least 25 t of fresh wood. In the future, use of remote controls and electronic tethers may allow a further cost reduction, which is estimated at 15%.

Recently the species Cynara cardunculus L. has gained importance for its multiple uses including the production of bio-plastic and bio-energy. However, the obtaining of different product requires specific technology, especially at the beginning of the production chain for raw material optimization. In this regard, the harvesting in the field is a fundamental task that already determines the characteristics of the final product and the potential full exploitation of the crop. In this regard, the present study aimed at testing the performance of a combine equipped with three harvesting systems to harvest cardoon. The performances of the combine were assessed by studying the working times, while the work quality was evaluated quantifying the losses of both capitula, including the seeds, and the aboveground biomass.

Giant reed (Arundo donax L.) is recognised as a promising energy crop. While many studies have been conducted on agronomic practices, specific researches on cost-effectiveness and energy demand of the harvesting phase are limited. In the present work, four different harvesting systems, already evaluated from a technical point of view, were considered: system 1, self-propelled forage harvester (SFPH) on low-yielding cultivation; system 2, mower plus SFPH; system 3, SFPH on high-yielding cultivation; system 4, shredder plus round-baler. Systems 1 and 2 were tested on a 1-year-old cultivation; systems 3 and 4 on a 3- and 4-year-old, respectively. The study was aimed at identifying the main factors affecting the economic and energy cost of harvesting. Crop condition, age of plantation, and yield had a key role in determining the field efficiency of the machine and, in turn, the extent of harvesting cost. The lower field efficiency of the SPFH when harvesting older and unevenly arranged plants (system 3) required a higher economic and energy cost. System 4 (shredding plus baling) showed the lowest economic cost (112.90 € h−1), while system 1 was the most energy-saving (4.46 GJ ha−1).

An efficient and simple one-pot procedure for selective etherification of 2-aryl-ethylalcohols has been achieved through Amberlyst 15-catalyzed reaction in dimethyl carbonate (DMC). Moreover, the polymer catalyst could be recovered and reused with no effect on its activity. The reaction mechanism involves the formation of phenonium ion which has been demonstrated by a C-C bond forming reaction. Theoretical studies are in agreement with and thus explain experimental results. (C) 2013 Elsevier Ltd. All rights reserved.

Conversely to fast pyrolysis, in which the most abundant product is the pyrolysis oil, intermediate pyrolysis generates comparable amounts of solid, gaseous and liquid products. The present work reports the results of intermediate pyrolysis experiments of lignocellulosic biomass performed in a semi-continuous stirred bed reactor, rated for a nominal capacity up to 1.5 kg h–1 of biomass feed. Bio-oil properties resulted similar to commercial fast pyrolysis oil in terms of organic-rich fraction, but a lower yield was attained. The oil contains an unusual large amount of water, probably due to long residence time and the catalytic effect of the accumulated char into pyrolysis reactor. Char was characterised and evaluated for agriculture applications, while the permanent gases were measured and evaluated as energy carrier for the process itself. These data can potentially be used in the design and modelling of larger-scale unit. [Received: May 6, 2016; Accepted: January 28, 2017]

In Short Rotation Coppice (SRC) of poplar, the weeds within the row have a detrimental effect.A photoelectric and capacitive sensors was used for detecting the poplar cuttings along the row.The detection system has proved able to recognize the poplar cuttings.The system appears suitable for a future evaluation on the intra-row weeding machines. For Short Rotation Coppice (SRC) cultivation, it is common practice to use herbicides during the first year, even if mechanical weeding is becoming an alternative practice for environmental and agronomic reasons. Much attention was paid to non-chemical weeding within the rows, but the low level of efficiency of available machinery has led to the development of automatic systems that are capable of weeding the spaces in the row and avoiding the plants.In the framework of this study, a photoelectric and a capacitive sensor (the latter specifically developed for identifying poplar cuttings), was tested. A small platform pulling the sensors was moved along a monorail in order to assess the capability of the sensors for localizing cuttings along the row. The study was conducted on one-year old poplar cuttings. At this stage the plants have little mechanical strength and are unable to withstand the impact of traditional mechanical probes situated on the retractable elements of weed control machinery (hoes, cultivators). Each sensor identified the plant according to its own functional parameters. The divergence between the response of the sensors and the actual position of the cuttings allowed for the accuracy assessment of detection.The capacitive sensor showed a higher amplitude of response in presence of a poplar cutting than the photoelectric sensor. No significant differences were observed for the various distances (0.15, 0.20 and 0.25m) of the detection system from the row and for the different speeds (1.0 and 1.5kmh-1) of the rail.The first results showed that the testing apparatus accurately detected poplar cuttings at the same speed used by common mechanical weed control machines. The sensors tested proved to be suitable to be included in intra-row weeding machines. This will be the main goal of future activities, an interesting prospect for firms producing agricultural machinery for biomass crops.

Two-pass harvesting of short-rotation forestry plantations offers the opportunity to accumulate large biomass stores without occupying costly industrial areas, while letting the biomass dry before comminution. This study aimed at developing a simple model for predicting moisture content reduction of short-rotation forestry poplar stems felled and windrowed in the field. In a controlled experiment, cut stem windrows were built and left in the field for up to 6 months (from early December to early June). Thus stored, poplar stems incurred a reduction of moisture content between 10 and 20 percent points. Drying rate varied with the period of storage, and it was faster for later felling dates. Precipitation accounted for 20 to 40 % of the drying rate. No dry matter losses due to microbial activity were recorded during the whole storage period, lasting up to 6 months. The models developed with this study are simple and robust, and allow precision management of collection operations in order to guarantee a constant flow of biomass to user plants.

A study to point out Italian primary energy consumption, the amount of biomass available for energy purpose, and the existing energy plants using biomass was carried out. The main data of the study, a summary of the Italian regulations for energy production and a critical view finalized to promote strategies for future actions are reported. The paper also reports a brief description of a demonstrative project to promote energy production at farm level.

Five years old poplar (Populus spp.) plantation represents an interesting model of productivity. The most attractive characteristics of this energy crop are the handling flexibility, the high yield of biomass per area unit and the good quality of the chips obtainable. The mechanical harvesting of five-years old poplar plantations requires the use of specialized forest machineries such as harvester, feller, forwarder and chipper. Usually, after felling, the working phases consist of extraction, stacking and chipping. Generally, the last one is carried out in a “static phase”, where the product is taken from staked logs by using a hydraulic arm having a gripper that feed the chipping machine. In order to introduce technological innovations for the medium rotation forestry harvesting, the Consiglio per la Ricerca e la sperimentazione in Agricoltura, Unità di ricerca per l’Ingegneria agraria (CRAING) of Monterotondo (Rome, Italy) has developed a five years poplar cutwindrower and a self-propelled chipper equipped with a pick up system. The prototype of cut-windrower is a semi-trailed machine powered by a 95 kW tractor (at least). It mounts a cutting system and a double pincer with variable positioning. During the cutting phase the plant is grasped by the double pincer which conveys and unloads the stem along the inter-row. The trees are placed parallel to the progress of the tractor, but oriented in the opposite direction. The biomass windrowed is then chipped in a dynamic phase directly from the inter row using the self-propelled chipper equipped with the pick-up head. In the first tests, the cut-windrower has reached an operative working capacity of 0.22 ha h-1, with an operative production of 44 t h-1. On the other hand, the self-propelled chipper has showed an operative working capacity equal to 0.18 ha h-1, and an operative production of 35 t h-1 about. Both machines have shown good quality of the work performed and the results obtained indicates that the work phases could be simplified in order to reduce both the time of use and the harvesting costs.

Woody Biomasses (from agriculture and forestry activities) are among the most promising renewable energy sources. Current literature describes woody biomass feedstock supply chains supporting biofuels and utilities industries: the potentially productive land area overheads required for biomass production may results in a complex logistic within the whole chain. Its effective enhancement requires significant changes in the logistics environment of energy plants for sustainable energy production and the sequence-dependent procurement chains for biomasses furthermore complicate these changes. According to this, optimizing harvesting and supplying operations turns out to be strategic within the framework of the current energy policy. In this work we present a case study carried out monitoring 57 short rotation forestry (SRF) production sites placed in Emilia Romagna Region, Northern Italy, all supplying the harvested biomass to the same biomass power plant placed in the province of Ravenna (Italy). The overall average yield of these sites was 55 t/ha, the site surfaces ranged from 0.3 to 20 hectares and the distance from the power plant ranged between 8.2 to 102 km with one production site only within 10 km from the power plant. Harvest and transport costs were calculated according to two different harvesting scenarios: i) single phase harvesting (one cutting/chopping machine + tractors and trailers); ii) double phase harvesting (cutting/mowing machine followed after 80 days by chopping machine + tractors and trailers). Results show that, according to the first scenario, at increasing distances overall harvesting and transport costs ranged from 8.9 to 21.0 ± 1.3 􀀍/t (average ± standard deviation), while, with reference to the second scenario, they increased from 10.3 to 23.8 ± 1.5 􀀍/t with the transportation costs accounting from 16 to almost 70% of the total costs.

In the Italian environments, the rapeseed (Brassica napus L.) is subjected, at ripening, to a seed shattering causing significant losses that reduce the yield and increase the oilseed rape seedbank in the soil. Meteorological events and mechanical harvesting are the main factors affecting the extent of seed dispersal. Lacking the availability of works investigating the actual losses during the harvest at large scale, the Consiglio per la sperimentazione e la ricerca in agricoltura, Unità di ricerca per l’ingegneria agraria (CRA-ING) has conducted a study in order to determine the effective seed losses at on-farm scale. The amount of losses of two combine headers, traditional for wheat and specific for oilseed rape harvest, was compared. The rapeseed header had a hydraulic sliding cut-bar and two vertical electric blade on both sides in order to reduce the pulling and tearing action between the cut-off plants and those still standing. The seed losses were evaluated before and during the harvesting by using plastic trays placed on the ground within the crop rows. The trays were arranged in a layout allowing the estimation of the seed losses of three different sectors of the combine headers. The results have demonstrated that, at farm level, the use of a specific oilseed rape header adapted and optimized for the crop requirements allows to obtain a level of seed losses (0,97% of total production), below the values reported in literature. For rapeseed, the higher losses are localized at the final parts of the head, where the plants are strictly intertwined.

Agricultural residues represent an important source of biomass for energy. Among the available biomass suitable for energy and available in Italy, pruning represents about the 20% of the total. About 1.184 million of hectares are planted with olive trees; the pruning residues coming from these plantations represent a wide source of biomass at National level. The authors tested six commercial pruning harvesters to determine harvesting losses and product contamination when recovering pruning residues. All harvesters used a mechanical pick-up to collect the residues and a shredder to reduce them into chips. Three different pick-up settings were tested and namely: 1 cm above ground level, manufacturer’s specification and 3 cm above ground level. Ash content in the shredded material was taken as a measure of contamination: the uncontaminated branch material collected directly from the trees had a value of 3.5%, whereas in shredded residues varied between 4.5% and over 5.5%, for the shortest and the longest distance between the pick-up and the soil surface, respectively. Harvesting losses were slightly, but significantly, related to pick-up setting, and mainly depended on machine type. Both machines have shown a good quality of the work performed and the results obtained indicates that the work phases could be simplified in order to reduce both the time of use and the harvesting costs.

One of the standard methods for the determination of the size distribution of wood chips is the oscillating screen method (EN 15149- 1:2010). Recent literature demonstrated how image analysis could return highly accurate measure of the dimensions defined for each individual particle, and could promote a new method depending on the geometrical shape to determine the chip size in a more accurate way. A sample of wood chips (8 litres) was sieved through horizontally oscillating sieves, using five different screen hole diameters (3.15, 8, 16, 45, 63 mm); the wood chips were sorted in decreasing size classes and the mass of all fractions was used to determine the size distribution of the particles. Since the chip shape and size influence the sieving results, Wang’s theory, which concerns the geometric forms, was considered. A cluster analysis on the shape descriptors (Fourier descriptors) and size descriptors (area, perimeter, Feret diameters, eccentricity) was applied to observe the chips distribution. The UPGMA algorithm was applied on Euclidean distance. The obtained dendrogram shows a group separation according with the original three sieving fractions. A comparison has been made between the traditional sieve and clustering results. This preliminary result shows how the image analysis-based method has a high potential for the characterization of wood chip size distribution and could be further investigated. Moreover, this method could be implemented in an online detection machine for chips size characterization. An improvement of the results is expected by using supervised multivariate methods that utilize known class memberships. The main objective of the future activities will be to shift the analysis from a 2-dimensional method to a 3- dimensional acquisition process.

Giant reed (Arundo donax L.) is a perennial rhizomatous grass that is currently indicated as an alternative crop for bioenergy production. Cultivation of giant reed for energy purposes requires the identification of an appropriate propagation technique, usually carried out with stem cuttings and rhizomes. Both methods are very efficient, but also very expensive as they require demanding and labor-intensive manual work. This study aimed at verifying the viability of a mechanical method for in situ rhizome extraction, using a modified stump grinder. Three different machine settings were tested with the goal of obtaining rhizomes with variable length, ranging between 4.4 and 6.4 cm. Survival rate and shoot production were used to determine the vitality of rhizomes with different lengths. The study confirmed the viability of mechanical rhizome production in giant reed nurseries.

Vegetable oils became a very popular bioliquid for renewable power and transport applications. At local level, the short chain production of vegetable oils is currently important in terms of sustainability and use of rural area. This present work investigates the development of vegetable oils production chain in the Tuscany territory, focusing also to valorisation of the co-products (i.e., oil cake). The work is based on the study of the cultivation of rapeseed and sunflower, and the creation of an extraction plant based on cold-screw pressing technology, in order to obtain a raw vegetable oil suitable as biofuel. The German DIN 51623 standard was adopted to investigate the quality of vegetable oils obtained from different oil crops. Vegetable oils quality was evaluated by comparing the oil produced by a bench press at lab scale, comparing the results in terms of process yields and lipid fraction recovered. Due to the high phosphorous content of rapeseed oil, out of the DIN limits, an experimental procedure to remove P content and restore the oxidation stability of the oils was performed. The results showed a substantial P reduction by adding 2 wt% of P-removing additive. The oil cake properties were evaluated in view of its potential use for bioenergy production, in particular in terms of metals content. [Received: December 5, 2015; Accepted: September 20, 2016]

Many negative effects of mechanical harvesting of grapes are attributed to damage and subsequent leakage of juice, often accentuated by high time between harvest and processing as well as high temperature. The presence of must in the product harvested by machine, which can reach very high levels (25-30% of the total mass), can cause several negative effects such as phenols oxidation, abnormal fermentation, skins maceration, etc. For that reason, an innovative system of handling and grapes transporting was developed in order to separate, once harvested, the liquid part (must) from the solid one (bunch of grapes and single grape), and then to apply different working process on each of them. Thanks to this system, it was possible to isolate the must in a closed tank and thus, immediately, preserve it by dry ice or liquid carbon dioxide, with the addition of enological chemicals (sulphur dioxide, ascorbic acid and tannin) to avoid chemical and microbiological modifications. The evaluation of wines throughout tests and sensorial analysis highlighted the better quality of the wines, obtained by the proposed technique compared with the traditional one, cause of higher presence of primary fragrances, better color, and a better balanced structure of the wine preserved by oxidation action.

A large share of the vegetable oil market is today shifting from food to the energy sector. This trend led to discussions about the chance of confliction between these two chains and its possible social and environmental consequences. Moreover the increasing interest in pure vegetable oils for energy and biodiesel production are associated to a period of market volatilities and high prices. The economics of the biodiesel production is suffering the actual market situation. In this framework, the present work presents the results of the OVEST (ESTerified Vegetable Oils) project, which is supported by the Tuscany region. Aim of the project is the investigation of the use of waste oil streams and by-products from food industry to obtain an alternative feedstock for bioliquids and biofuels production. In the current food market, a number of secondary streams are available from the food industry: oleins and fatty acids, sludge oils and WCO (Waste Cooking Oils), represent several examples of these potential alternative feedstock. Most of these materials are characterized by high free fatty acid compositions. In the OVEST project, vegetable oil is obtained from waste materials by the re-esterification process, in order to obtain a new feedstock for biodiesel production and for power generation. A market analysis has been carried out in OVEST, to estimate the economic viability and the potential of each waste streams. Test on a modified Micro Gas Turbine (30 kWel) and in small scale co-generator (5 kWel) have been carried out. Performances and pollutant missions were monitored. The results of the experimentation confirmed the viability of these fuels for the energy production. From the environmental point of view, the use of these feedstock allows to meet the requirements of the European Directive EC/28/2009 (RED), that introduces minimum targets in terms of GHGs saving for bioliquids and biofuels. The present work showed that most of the input materials to the esterification process may be classified as wastes or residues, and that assuring an accurate traceability for each treatment and transport phase is a really complex issue. However the high GHG savings potential, as indicated in the RED for bioliquids from wastes, was confirmed by the work here carried out. Therefore OVEST project demonstrates the viability of the use of esterified oils as biodiesel feedstock or for direct energy generation, starting from a renewable source, non competing with food market and with a high GHG saving potential.

Wood chips need to fulfill specific quality parameters in order to be used as fuel for industrial or residential use. Moisture content and chip size distribution are recognized as the main physical characteristics affecting energy conversion efficiency. Objective of the study was to evaluate the effects of harvesting mode on the quality of wood chips, under the typical conditions offered by SRC poplar grown in Central Italy. Single-pass and two-pass harvesting were compared. Standing stems and cut windrowed stems were harvested using two modified foragers alternately equipped with a drum or a disc chipper, allowing a further comparison of different chipping devices. Data were obtained from 3 fields in Central Italy and allowed analyzing the drying process occurring when stems are felled and stored in the field as windrows. The mean water content at the time of cutting was 59% (wH2O), which was reduced below 30% after about 100 days of storage in the windrows. Regression analysis of storage duration and moisture content showed that air temperature is the main driver of the drying process, under the typical conditions of a Mediterranean climate. Harvest mode (single-pass or two-pass) and chipping device (drum or disc) have a significant effect on particle-size distribution. The incidence of accept particle was higher when chipping windrowed stems or using the drum chipper. The paper discusses the advantages of two-pass harvesting and emphasizes the importance of flexibility when choosing harvest mode and chipper type. © 2013 Elsevier Ltd. All rights reserved.

A novel and efficient synthesis of pyrogallol moiety through a copper(I)-mediated C–O bond forming reaction is described. In particular, syntheses of 3,4,5-trihydroxyphenethyl alcohol and its methyl derivative are reported. Particular attention to dimethyl carbonate as an eco-friendly solvent/reactant has been paid, in order to improve the eco-compatibility of the whole synthetic pathway. Furthermore, the genotoxicity, cytotoxicity and the antioxidant activity of 3,4,5-trihydroxyphenethyl alcohol and its methyl derivative have been investigated.

We set out to determine the particle-size distribution, the fiber, the bark and the leaves content, the heating value, the CNH and the ash content of a wide sample of wood chips, collected from 10 forestry and 10 agroforestry production sources. This sampling focused on two main production types: forestry (Full Tree System—FTS—and logging residues—LR) and agroforestry(Short Rotation Coppice—SRC). For the forestry production wood chips from coniferous and broadleaf species were considered. For the agroforestry production wood chips from poplar plantations were examined (different clones with two different harvesting intervals). Overall, we collected 400 samples. Particle size distribution was determined with an automatic screening device on 200 samples. The higher heating value was determined on 200 subsamples using an adiabatic bomb calorimeter. The CNH and the ash content was ascertained on another 200 subsamples. FTS and SRC (with three year old sprouts) offered the best quality, with high fiber content (71%–80%), favorable particle-size distribution and good energetic parameters. On the contrary, both logging residues and SRC (with two year old sprouts) presented a high bark content (18%–27%) and occasionally a mediocre particle-size distribution, being often too rich in fines (6%–12%), but the energetic parameters are in the normal range.&nbsp

Biofuels is currently driving the interest in bioenergy sector. The recently issued Renewable Energy Directive (2009/28/EC) confirms the 10% target, set by the EC, for energy from renewable sources in transport. The European Union is the largest producer of biodiesel in the world and biodiesel is also the most important biofuel used in the EU. The aim of this paper is to investigate the biomass feedstock requirement, under different scenarios, with a focus on vegetable oils. The European production potential is compared with the amount of biomass required to meet the target on biofuels. Next generation biofuels and alternative feedstock for first generation pathways are considered as well as the share of biomass import. The scenario proposed allows to estimate the land required to meet the target at 2020 on biodiesel. Assuming different contribution of the next generation biofuels, from the 10% to the 30% is possible to estimate the contribution of first generation biodiesel. The results showed that, considering the total European arable land, this production will utilise 9–13%.

Mechanised cut-to-length (CTL) harvesting is commonly deployed in eucalypt plantations and is based on the application of specialised machinery for felling, delimbing, debarking and crosscutting trees directly at the stump site. Debarked logs are then moved to the roadside with dedicated forwarders for loading onto transportation vehicles. This study determined the cost of stump-site debarking, which was calculated between 1.7 and 6.7EURm -3, depending mainly on tree size. Avoiding stump-site debarking would allow reducing the overall stump-to-road harvesting cost between 11 and 17%, while making bark biomass available for energy or biochemical conversion. The figures obtained from this study are specifically valid for European pulpwood plantations and winter harvest conditions, but the underlying principles may hold a general significance. Further studies should determine the cost of off-site debarking, and the effects of bark removal on soil fertility.

The author, gathering from bibliography data which have been published on the present situation and exchanging information with experts in the field of agricultural and energetic production evaluate the future previsions about supply and demand of biomass in Italy.

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).

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