48 research outputs found

    Sustainability of sunflower cultivation for biodiesel production in central Italy according to the Renewable Energy Directive methodology

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    The use of renewable energies as alternative to fossil fuels has value from different points of view and has effects at environmental, social and economic level. These aspects are often connected to each other and together define the overall sustainability of bioenergy. At European level, the Directive 2009/28/EC gives the basic criteria for the estimation of sustainability of biofuels and indicates a minimum threshold of 35% of greenhouse gas saving for a biofuel in order to be considered sustainable. The Directive gives the possibility to identify standard regional values for the cultivation steps that could be utilized for the certification. This paper aims to give a contribution to the definition of these values considering the RED methodology applied to the sunflower cropped in central Italy which is characterized by a hilly landscape and not-irrigated crops. To determine input and output of sunflower cultivation in the central Italy, the results of PROBIO project, carried out by the Authors, were used. The sustainability of biodiesel produced from sunflower grown in central Italy is variable and depends on the nitrogen input and seasonal climatic conditions that affect the yields. The greenhouse gases savings of the Italian chain is 40% in average, greater than the required 35% and would be possible to assign this value as standard to the biofuel chain biodiesel from sunflower cultivated in central Italy. Using an averaged regional standard value guards against the possibility of considering unsustainable harvesting in unfavourable years and seeing it overestimated in the favourable ones

    Solid biofuels production from agricultural residues and processing by-products by means of torrefaction treatment: the case of sunflower chain

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    The high heterogeneity of some residual biomasses makes rather difficult their energy use. Their standardisation is going to be a key aspect to get good quality biofuels from those residues. Torrefaction is an interesting process to improve the physical and chemical properties of lignocellulosic biomasses and to achieve standardisation. In the present study torrefaction has been employed on residues and by-products deriving from sunflower production chain, in particular sunflower stalks, husks and oil press cake. The thermal behaviour of these materials has been studied at first by thermogravimetric analysis in order to identify torrefaction temperatures range. Afterwards, different residence time and torrefaction temperatures have been tested in a bench top torrefaction reactor. Analyses of raw and torrefied materials have been carried out to assess the influence of the treatment. As a consequence of torrefaction, the carbon and ash contents increase while the volatilisation range reduces making the material more stable and standardised. Mass yield, energy yield and energy densification reach values of about 60%, 80% and 1.33 for sunflower stalks and 64%, 85% and 1.33 for sunflower oil press cake respectively. As highlighted by the results, torrefaction is more interesting for sunflower stalks than oil cake and husks due to their different original characteristics. Untreated oil press cake and husks, in fact, already show a good high heating value and, for this reason, their torrefaction should be mild to avoid an excessive ash concentration. On the contrary, for sunflower stalks the treatment is more useful and could be more severe

    Experiments on torrefaction of Dichrostachys cinerea wood: two-level factorial design and thermogravimetric analysis

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    The aim of this study was to determine the effect of the temperature and reaction time variables on the solid yield and the increment of heating values and composition of torrefied Dichrostachys cinerea wood by using a factorial experiment design and thermogravimetric analysis. The significant factors were identified by means of a two-level factorial design type (22), for which the statistical software Design Expert version 10 was used. Torrefaction and thermogravimetric experimental runs were carried out in a fixed-bed reactor and thermobalance TGA–DTA, respectively. Torrefaction temperature, residence time and their interaction have a significant effect on solid yield, whilst the effect of the temperature was the only statistically significant factor on increment at a high heating value (HHV). The R-Squared values for both response variables were greater than 95% in each case. An increase in torrefied biomass was achieved at HHVs of 14.92 and 30.31% under the conditions of 120 min at 250 and 290 °C, respectively. Thermogravimetric characterisation and DTG–TG curves of the torrefied material suggest that the pre-treated material has been modified chemically and structurally.This research was financed by a doctoral scholarship from the Università Politecnica Delle Marche, Ancona, Italy, and supported by the Department of Chemical Engineering, University of Alicante, Alicante, Spain

    005_Foppa_Pedretti(567)_35

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    ___________ 1 A Google search for "renewable energy" (with the string in inverted commas in order to search for the words in this sequence) yields more than 17 million (M) hits; a search for "energy" produces more than 350 M hits, placing it in reassuring competition with "food" (over 600 m hits). However, when limited to PDF files (i.e. documents available for download, which are likely to be reports of a certain value), the search yields more than 3 M hits for "renewable energy" and less than 55 M for "food". These data, confined to the English language, are partial but highlight various questions, in particular the huge amount of material available on the Web. Its sheer quantity would require a summarizing effort directed at identifying relevant material for teaching purposes and for spreading research results. 2 This view is widely held, with Hubbert a major points of reference (http://www.hubbertpeak.com). Given the scarcity of fossil resources, some authors propose focusing EU university curricula on "renewable energy sources" and "agricultural engineering". 3 This view has a narrower following but the literature is usually highly qualified. 4 Among various actions, one in particular deserves to be mentioned -the setting up of the Intergovernmental Panel for Climate Change (IPCC), whose remit is to study climate change and its causes. At the EU level the IPCC reports have led to an articulated body of rules aimed at reducing CO 2 emissions that will become increasingly restrictive over time

    fast measurement by infrared spectroscopy as support to woody biofuels quality determination

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    The increase in the demand for energy supply during the past few decades has brought and will bring to a growth in the utilisation of renewable resources, in particular of solid biomasses. Considering the variability in the properties of biomass and the globalisation of the timber market, a chemical and physical characterisation is essential to determine the biomass quality. The specific international standards on solid biofuels (ISO 17225 series) describe proper specification and classification of wood chip and pellet, to ensure appropriate quality. Moreover, standard requires information about origin and source of the biomass, normally only to be declared by the producers. In order to fulfill the requirements for the biomass quality, the origin and the source should be assessed, even if currently is hard to determine, in particular on milled or densified biomass. Infrared spectroscopy can provide information on the biomass at the chemical level, directly linked also to its origin and source. This technique is fast and not destructive thus suitable also for online monitoring along the biofuel production chain. In this study, 60 samples belonging to 8 different species were collected and related spectra were acquired using a Fourier transform infrared (IR) spectrometer equipped with a module for solid analysis and analysed by principal component analysis. The results obtained show that the method is very efficient in the identification between coniferous and deciduous wood (99% confidence level) and good results were obtained in the recognition of coniferous/deciduous mixtures, too. Nevertheless, some clear differences have been also noted among intra-class grouping, but additional tests should be carried out. This technique can provide useful information to solid biofuel stakeholders about wood quality and origin, important especially for sustainability issues. Further work will be oriented to the development of IR methodologies for the fast measurement of other important biomass parameters (e.g., ash content, high calorific value, nitrogen content, etc.)

    Experimental Study to Support Local Sunflower Oil Chains: Production of Cold Pressed Oil in Central Italy

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    Sunflower is one of the most important oilseed crops cultivated in the world for different purposes. In Italy, the production is mostly located in the central area, representing 70% of Italian production. The market demand for sunflower oil is higher than the national production. There is an increasing request for cold pressed sunflower oil for food application. The success of this activity is linked to a correct setting up and management of the production and supply chain with a valorization of products and by-products. To this aim, information is needed, and this paper is focused on the cultivation of sunflower in central Italy using suitable hybrids, as well as on the study of the cold extraction performance of the sunflower seed produced and the quality of by-products and residues. Results indicate that, on average, a range of about 1.0–1.5 t ha−1 of cold pressed oil and different amounts of by-products can be obtained. According to a proposed scenario, 30 ha cultivated with sunflower are needed to create a complete supply chain within the farm, avoiding many additional passages and maintaining all the value for the farmer. It is important to use suitable hybrids for obtaining good yield, but also the cold extraction performances are important because they also affect the quality of by-products and residues that can be valorized themselves to improve sustainability

    La nuova viticoltura - Capitolo 11. Carbon Footprint

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    Questo volume guida concretamente il viticoltore tra le più recenti innovazioni inerenti le scelte progettuali, la gestione del vigneto, l'automazione, la robotica, l'impronta del carbonio, la valorizzazione dei residui/sottoprodotti, la difesa/protezione, il contenimento dell'impatto ambientale ed i sistemi di supporto alle decisioni allo scopo di individuare nuove opportunità ed eventuali punti critici per ottimizzare i processi produttivi e valorizzare il territorio nella ferma convinzione che "il grande vino nasce nel vigneto
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