1,721,199 research outputs found
The effect of ash composition on gasification of poultry wastes in a fluidized bed reactor
No full textThe effect of ash composition on the fluidized bed gasification behaviour of poultry wastes was investigated by operating a pre-pilot scale reactor with two batches of manure obtained from an industrial chicken farm. The experimental runs were carried out by keeping the fluidized bed velocity fixed (at 0.4m s-1) and by varying the equivalence ratio between 0.27 and 0.40, so obtaining bed temperature values between 700 and 800 °C. The performance of the gasification process was assessed by means of mass balances as well as material and feedstock energy analyses, and reported in terms of cold gas efficiency (CGE), specific energy production, low heating value of obtained syngas and yield of undesired by-products. The experimental results indicate the crucial role of ash amount and composition of the two poultry wastes. In particular, higher ash content (25.1% instead of 17.2%) and higher fractions of calcium, phosphorous and potassium (with an increase of 24, 30 and 28%, respectively) induce a dramatic reduction of all the process performance parameters: CGE reduces from 0.63 to 0.33 and the specific energy from 2.1 to 1.1 kWh kgfuel-1. At the same time, the formation of alkali compounds and their behaviour inside the fluidized bed reactor determine an increase of feedstock energy losses, which is related to occurrence of sintering and bridging between bed particles. © The Author(s) 2014
Fluidized bed gasification of a packaging derived fuel: Energetic, environmental and economic performances comparison for waste-to-energy plants
No full textA comparison of possible solutions for small scale (0.2-1. MWe) waste-to-energy gasification-based industrial application is presented. A pilot scale bubbling fluidized bed air blown gasifier, having a capacity of 500. kWe, provided experimental data: the syngas complete composition as well as the characterization of the bed material and contaminants downstream of the cyclone and wet scrubber. Mass and energy balances and material and substance flow analyses have been drawn to assess and compare design solutions utilizing a packaging derived fuel (PDF) obtained as scrap by food industrial processes. The related environmental, energetic and economic performances have been estimated on the basis of the experimental data and manufacturer's specifications. In the scale range analyzed, the best solution is that of a power gasification coupled with an internal combustion engine, which provides high reliability and high internal rate of return. © 2012 Elsevier Ltd
Gasification of a solid recovered fuel in a pilot scale fluidized bed reactor
No full textThe paper investigates the technical feasibility of an air gasification process of a Solid Recovered Fuel (SRF) obtained from municipal solid waste. A pilot scale bubbling fluidized bed gasifier, having a feedstock capacity of about 70 kg/h and a maximum thermal output of about 400 kW, provided the experimental data: the complete composition of the syngas (including the tar, particulate and acid/basic gas contents), the chemical and physical characterization of the bed material and that of entrained fines collected at the cyclone. The experimental runs were carried out by reaching a condition of thermal and chemical steady state under values of equivalence ratio ranging from 0.25 to 0.33. The results indicate that the selected SRF can be conveniently gasified, yielding a syngas of valuable quality for energy applications. The rather high content of tar in the syngas indicates that the more appropriate plant configuration should be that of a "thermal gasifier", with the direct combustion of the syngas in a burner ad hoc designed, coupled with an adequate energy-conversion device. © 2013 Elsevier Ltd. All rights reserved
Alla scoperta dei tesori geologici della Sardegna. Cala Domestica (Sardegna sud-occidentale). Geoitalia, Ottobre 2008, N° 24, pp. 38-39, Livorno
No full textThe intricate brain–body interaction in psychiatric and neurological diseases
Full text linkA harmonic brain-body communication is fundamental to individual wellbeing and is the basis of human cognition and behavior. In the last 2 decades, the interaction between the brain and body functioning has become a central area of study for neurologists and neuroscientists in clinical and non-clinical contexts. Indeed, brain-body axis dysfunctions occur in many psychiatric, neurological and neurodegenerative diseases. This editorial will focus on recent advances and future therapeutic perspectives for studying brain-body interactions in health and diseases
Element partitioning in combustion- and gasification-based waste-to-energy units
No full textA critical comparison between combustion- and gasification-based waste-to-energy systems needs a deep knowledge of the mass flows of materials and elements inside and throughout the units. The study collected and processed data from several moving grate conventional incinerators and high-temperature shaft gasifiers with direct melting, which are in operation worldwide. A material and substance flow analysis was then developed to systematically assess the flows and stocks of materials and elements within each waste-to-energy unit, by connecting the sources, pathways, and intermediate and final sinks of each species. The patterns of key elements, such as carbon, chloride and heavy metals, in the different solid and gaseous output streams of the two compared processes have been then defined. The combination of partitioning coefficients with the mass balances on atomic species and results of mineralogical characterization from recent literatures was used to estimate a composition of bottom ashes and slags from the two types of waste-to-energy technologies. The results also allow to quantify some of the performance parameters of the units and, in particular, the potential reduction of the amount of solid residues to be sent to final disposal. © 2013 Elsevier Ltd
Advances in EEG-based functional connectivity approaches to the study of the central nervous system in health and disease
Full text linkFunctional brain connectivity is closely linked to the complex interactions between brain networks. In the last two decades, measures of functional connectivity based on electroencephalogram (EEG) data have proved to be an important tool for neurologists and clinical and non-clinical neuroscientists. Indeed, EEG-based functional connectivity may reveal the neurophysiological processes and networks underlying human cognition and the pathophysiology of neuropsychiatric disorders. This editorial discusses recent advances and future prospects in the study of EEG-based functional connectivity, with a focus on the main methodological approaches to studying brain networks in health and disease
Proposta di una Carta di interesse naturalistico, geoturistico e culturale lungo il tracciato del Trenino Verde (Sardegna centro-orientale)
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