1,721,031 research outputs found
Environmental benefits of valorising cattle manure for household cooking energy in Uganda
No full textThis study employed the Life Cycle Assessment (LCA) methodology to evaluate the environmental impacts of utilizing cattle manure as a substrate for biogas generation for cooking energy in Uganda. Results of the study showed that biogas energy systems based of cattle manure has potential environmental benefits in comparison to charcoal produced from natural forests. Under baseline scenario, without recycling of slurry as fertilizer, the biogas system leads to total environmental impacts of over 80% less than that of charcoal system. When slurry is utilized as substitute mineral fertilizers, the environmental impact of biogas system was found to be less than that of charcoal by close to 95%. The study further showed that that use of biogas could lead to considerable reduction on human health impacts compared to charcoal. In conclusion, utilization of cattle manure for biogas production has potential benefit of reducing the environmental impacts due to charcoal production and use in Uganda
Disponibilità di biomasse agro-forestali e residui di potature in Campania
No full textLe biomasse forestali sono da anni oggetto di attenzione per la loro utilizzazione a fini
energetici. Al contempo vengono progettati o anche realizzati una quantità di impianti
per la produzione di energia da biomasse, prescindendo da opportune considerazioni
sulla disponibilità effettiva di residui forestali e prescindendo da considerazioni sulla
logistica. Inoltre le valutazioni sulla disponibilità di biomasse sono troppo spesso
superficiali, non tengono conto dell’attuale impiego (pannelli di truciolato o
riscaldamento domestico) e non tengono in sufficiente considerazione i costi di
raccolta. Attualmente sono in fase di realizzazione o progettazione in Campania
impianti a biomasse per oltre 50 MW di potenza e v’è dubbio sulla possibilità di
alimentarli con biomasse autoctone. Con questo studio sul territorio campano, condotto
con un GIS basato sull’uso del suolo da immagini telerilevate, sono state quantificate le
superfici arboree e forestali della regione e da queste sono state stimate le quantità di
biomasse effettivamente detraibili per fini energetici. Anche i costi di
approvvigionamento sono stati valutati ed in base alle quantità previste ed ai costi si
dimostra che non sarà possibile facilmente alimentare questi impianti con biomasse
forestali autoctone. Assai interessanti potrebbero essere i sarmenti di vite e le altre
potature a condizione di sviluppare una specifica filiera logistica che è attualmente
l’anello debole. Occorre una rete di micro-centri di gestione in cui vengono raccolte e
prelavorate le potature e gli scarti forestali
Experimental Evaluation of Manure Evaporation in The Paddock for a Management Algorithm Development
No full textThe aims of this study was to evaluate the possibility of reducing the weight of manure in
paddocks by natural evaporation according to an appropriate management plan. The weight
of buffalo manure was recorded by an experimental platform equipped with load cells and
installed within the paddock. The data was used for assessing the real evaporation of
manure in situ. A model for predicting manure evaporation was developed by adapting a soil
evapotranspiration model. On the basis of the model an optimal management strategy was
established, which corresponds to minimizing the use of the scraper from the 100
th
day of the
year (DOY) to the 250
th
DOY. This lead to a potential reduction in weight of the manure by
650 kg/m
2
/year which corresponds to management cost reduction of about 30%. This
approach is effective for reducing the bulkiness of buffalo manure for which the spreading
costs per kg of nitrogen and the fuel needs for land application is very substantial considering
its low nitrogen content of about 2 mg/m
3
Effect of Short Rotation Coppice Plantation on the Performance and Chips Quality of a Self-Propelled Harvester
No full textThe performance of coppice harvesting machines is influenced by parameters such as field yield, the shape and size of the plantation and the space for turning at the headland. The quality of chips and the effect of the dendrometric characteristic of nine different species (Fraxinus angustifolia, Robinia pseudoacacia, Salix alba, Eucalyptus occidentalis, Populus nigra L. and four genotypes of Populus x euroamericana (Grimminge, Hoogvorst, Muur, Vesten) grown in the same flat plot of about 4.5 ha on the performance rate and quality of the work, was evaluated. Field yields ranged from 33 t ha-1 to ~ 95 t ha-1, for the S. alba and E. occidentalis, respectively. The harvester worked with an average speed of 0.91 m s-1 (±0.22) and average productivities of 0.98 ha h-1 (±0.24) and 45.25 t h-1 (±5.56). There was a satisfactory linear correlation between the working speed of the machine and field yield. The quality of the chips showed some variability with values of moisture content ranging between 42.7% and 57.3% (for R. pseudoacacia and S. Alba respectively) and values of bulk density from 273 kg m-3 to 313 kg m-3 (for P. euroamericana Vesten and E. occidentalis respectively)
Bioenergy potential of agricultural and forest residues in Uganda
No full textBiomass is the major source of energy in most developing countries. However, there are concerns about the sustainability of biomass supplies and the environmental impacts resulting from their use. Use of residues could contribute to ensuring sustainable supply of biomass energy. This study presents findings of an evaluation of the energy potential of agricultural and forest residues in Uganda using census data of the year 2008/2009. Annual productions of crop and forest residues were estimated using residue-to-product ratio (RPR) method. Energy potential of each residue class was then determined basing on their respective lower heating values. The biogas generation potential of each animal category was used to evaluate the energy potential of animal manure. Results showed that the total energy potential of the residues amount to 260PJy-1, which is about 70% of gross biomass energy requirement of Uganda for the year 2008. Crop residues had the highest contribution of about 150PJy-1, followed by animal residues with a potential of 65PJy-1. Maize residue is the predominant crop residue with energy potential of 65PJy-1 followed by beans and banana, each at 16PJy-1. This study indicates that agricultural and forest residues can be a major renewable energy source for Uganda. When sustainably utilised, biomass residues could contribute to reduction in environmental degradation in the country
Biorefinery development in livestock production systems: Applications, challenges, and future research directions
Full text linkSustainable development and reducing natural and energy resource consumption are the focus of the policies of many institutions. In this context, livestock farming is one of the major anthropogenic sources of GHG and acidifying gas emissions and requires comprehensive analysis to minimise its ecological footprint. For this reason, it is beneficial to analyse the various processes within this production sector to reduce the consumption of resources, particularly water and soil consumption; reduce energy consumption; and try to valorise the biowaste produced, especially manure, byproducts and wastewater. Reusing residual bioresource and organic waste offers the possibility of valorising a discarded product and, at the same time, reducing the consumption of natural resources. For this purpose, biorefinery processes allow bioresources to be transformed into bioproducts or bioenergy. Therefore, this study investigates the application of biorefinery processes to animal-derived waste, aiming to extract valuable resources while curbing resource consumption. This review analysed 293 scientific papers on biorefinery processes published in the last 11 years applied to livestock biomass to extract relevant information to understand the evolution of this topic and formulate hypotheses regarding future research directions. The analysis strongly emphasises energy production and a growing interest in insect cultivation. In the coming years, one of the most significant challenges will be the successful transfer of technologies and processes from experimental research to the applied industry. To do this, it will be necessary to reduce costs, exploit economies of scale, improve process management, and develop synergies between different industrial sectors to implement smart circular economy systems. Overall, this review aims to clarify the hypothesis driving research in this area and emphasizes the tangible applications of findings within the broader context of sustainable resource management
Measurement and Prediction of Buffalo Manure Evaporation in the Farmyard to improve Farm Management
No full textIn order to evaluate the performance of two empirical models for buffalo (Bubalus bubalis) manure evaporation, predictions were compared with measured data. The two models were developed by adapting the potential evapotranspiration (ETo) models of Tombesi-Lauciani and Hargreaves. The data used for assessing the manure evaporation in situ, were derived from the manure weights recorded using an experimental platform installed within the farmyard and equipped with load cells. The experiments were carried out in Serre (SA), in the South of Italy in the period from 23 June to 24 September 2011. The most efficient model, in terms of closeness between estimates and measures, was implemented from 2006 to 2010, allowing for annualised calculation of evaporation. On this basis, an optimal management strategy was established, which corresponds to maximising manure evaporation, minimising the use of the scraper from the 100th day of the year (DOY) to the 250th DOY. This leads to a potential reduction in weight of the manure by 650 kg m-2 [yard] year-1, which corresponds to management cost reduction of about 30%. © 2013 IAgrE
Development of bioenergy technologies in Uganda: A review of progress.
No full textBiomass is a renewable energy resource; however, its exploitation raises concerns about its ability to sustain the growing demand and its negative impacts on the environment, particularly in developing countries. These concerns are more prominent on the African continent where high population growth rates is leading to high rates of deforestation due to expansion of agricultural land and increased demand for bioenergy. Use of traditional and inefficient bioenergy technologies and appliances also exacerbate the problem. This paper presents a review of the efforts and progress made by different organisations in promoting improved bioenergy technologies in Uganda. The study was based on an extensive review of available literature on improved bioenergy technologies introduced in the country. It was found that there is high level of wastage of biomass resources since an estimated 72.7% of the population use traditional cooking stoves with efficiency estimated to be less than 10%. Inefficient cooking stoves are also blamed for indoor air pollution and respiratory illness reported amongst its users. Modern bioenergy technologies such as biomass gasification, cogeneration, biogas generation, biomass densification, and energy-efficient cooking stoves have been introduced in the country but have certainly not been widely disseminated. The country should pursue policies that will accelerate proliferation of more efficient bioenergy technologies in order to reduce the negative environmental impacts of bioenergy utilisation and to ensure sustainability of biomass supplies. © 2012 Elsevier Ltd. All rights reserved
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