1,721,030 research outputs found
Project Alter-Energy. Demonstrative utilisation of alternative sources of energy in Moldova trough crop cultivation experimentation
No full textLe lavorazioni meccaniche conservative e le cover crop in una rotazione triennale ad indirizzo biologico
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Confronto tra sistemi colturali a ridotto impatto ambientale per il girasole destinato alla produzione di biodiesel
No full textCome produrre olio vegetale e quanto costa
No full textNell’ambito del progetto “Sostenibilità economico-aziendale della produzione di biocombustibili da biomasse a filiera corta”, finanziato dalla Regione Friuli Venezia Giulia, è stata attuata una sperimentazione volta alla produzione di energia direttamente da biomassa proveniente da attività agricola presso l’Azienda Agraria “A. Servadei” dell’Università degli Studi di Udine.
In particolare, l’obiettivo è stato quello di produrre energia elettrica e termica, predisponendo una filiera corta a livello aziendale in modo da ottenere, almeno in parte, la produzione dell’olio vegetale necessario per l’alimentazione di un motore cogenerativo, partendo dalla produzione del seme, dal suo processamento, fino all’utilizzo diretto come biocombustibil
Assessment of energy sustainability and carbon footprint of a Jatropha-biofuel chain in rural area of Brazil
No full textBecause of the world population growth and increasing energy demands, renewable energy sources are seen as valid fossil fuel alternatives that could guarantee environmental benefits. In this context Jatropha curcas L. has been identified as a promising feedstock for biofuel production and promoted as a sustainable biofuel crop. This paper analyzes the creation of a Jatropha-oil chain in a rural area in north-eastern Brazil (Ceará State) utilizing the Life Cycle Assessment (LCA) method. The aim of this study is to evaluate the energy sustainability expressed as cumulative energy demand (CED) and carbon footprint expressed as global warming potential (GWP) of a Jatropha-oil chain in comparison with fossil fuel (diesel). The component with most impact on the Jatropha-oil chain was electricity consumption, which accounted for 42% and 63% of CED and GWP, respectively. The analyzed Jatropha biofuel-chain presented a more favourable energy balance (94% of CED saved) and a lower effect on global warming (77% of greenhouse gas emission, GHG, avoided) in comparison with diesel fossil fuel. If the biofuel produced, instead of being used locally, was exported over a long distance (i.e. to the European Union), the energy and environmental benefits obtained were completely nullified. Crop management practices based essentially on manual labour of family farming system, as in the present study, determined a positive influence on the energy balance and carbon footprint in the Jatropha-oil chain. On the contrary, a crop management practices making high use of inputs (fertilizers, pesticides, irrigation ...) on large areas of monoculture, could negatively affect the socio-economic sustainability of the whole Jatropha-biofuel chain
Seed processing and oil quality of Jatropha curcas L. on farm scale: A comparison with other energy crops
No full textThere are many examples of small-scale initiatives, based on exploitation of the jatropha-crude oil chain, to provide
energy at local level, especially in the rural areas of a developing country, where mechanical pressing is currently
themostwidely used process to extract oil fromseed. This study is a comparative analysis of the extraction
performance parameters and the quality of the cold pressed oil obtained utilizing a commercial single screw
extruder at the farm level for the extraction of Jatropha curcas, sunflower and rapeseed oil. In the case of
J. curcas, the best operating results were obtained at a seed feed rate of 25.7 kg/h yielding about 8 kg/h of oil.
This result, although satisfactory, was much lower than that of the rape and sunflower seeds. The levels of the
main mineral contents (phosphorus, calcium and magnesium) in the jatropha oil, are significantly higher than
those specified in the DIN V 51605 standard. Moreover jatropha oil showed high K and Na content (N2 ppm),
the elements that promote deposit formations in engines, while these were not detectable in rapeseed and sunflower
oil. Preventive measures (optimizing harvest and storage condition) and avoiding an excessive rise in oil
temperature (b50 °C) during the extraction process are necessary to improve the quality of the jatropha crude
oil. In order to meet the quality standards of the new DIN 51506, in order to reduce the mineral elements content
in the jatropha oil (especially P, Ca + Mg) inert additives may be mixed with the oil during the seed processing,
but these additives can lower the oxidation stability of the oil, so a stabilizer also needs to be added. Moreover
these steps complicate the technological process and lower the commercial value of the oil, clearly demonstrating
the advantage of producing oil with low concentration of P, Ca + Mg and K + Na in the first plac
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