973 resultados para calorific value
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Pós-graduação em Ciência Florestal - FCA
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Charcoal is obtained from carbonization, much used in the steel industry for ore reduction, using as raw material the Eucalyptus. The present study aims to verify whether the main Eucalyptus saligna genetically modified produce quality charcoal with only 3.5 years old. The study was done with material collected from three trees, divided into five discs removed at 0, 25 , 50 , 75 and 100 % of the commercial height of the tree. The procedures adopted were based on standards published by ABNT. The results were satisfactory for the parameters: basic wood density with an average of 0.39 ± 0.0082 g / cm ³; volatile materials from coal with an average of 19.35 ± 3.27 %, fixed carbon content of the coal with an average of 75.62 ± 3.40 % and gross calorific value of coal with an average of 4694.43 cal / g, and unsatisfactory results for ash content averaging 5.03 ± 0.23 when compared to the values found in the literature. It was concluded that the studied wood is able to produce charcoal, but the factors of production should be better observed, such as heating time which exerted direct influence on the determination of ash content
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With the growing world energy demand mainly from developing countries like Brazil, Russia, India and China, the search for efficient sources of energy becomes a challenge for the coming years. Among the most widely used alternative sources, biomass is the one that grows in a more pronounced way. This study will assess the real possibility of having it as a heat source in an Organic Rankine Cycle, which employ heat transfer fluids as working fluids instead of water. From a regional data collection in agricultural production and their potential rice production and the resulting husk was defined as more appropriate. The availability of husks together with an amount of eucalyptus wood, provided by a company in the region on a monthly basis, were analyzed, and the low participation of the wood was discarded by the thermal contribution of little significance. Based on this, it was established the calorific value of fuel for thermodynamic calculations and the cycle to be used. It was then carried out the choice of working fluid from the literature and their availability in the library of software used for the simulations, the Engineering Equation Solver - ESS. The fluid most appropriate for the burning of biomass, Octamethyltrisiloxane (OMTS), was not included in the software and so the R227ea and R134a were selected. After the initial parameters modeling definition, as condensing temperature, efficiency and live steam conditions, the simulations were performed, and only the R227ea remained within the feasible thermodynamic and technological ranges. With this fluid the turbine power output was 265.7 [kW] for a scenario of 24 hours/day burning, 800.3 [kW] to biomass burning for 8 hours/day and 2134 [kW] for burning only 3 hours/day. The thermal efficiency of the cycle remained in the range of 6%, and for plants operating with the most... (Complete Abstract click eletronic access below)
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In this work is studied the fluid dynamic characteristics of sugarcane bagasse for gasification applications and use of syngas in the sugarcane sector. This is an experimental work, which is initially performed the particle size separation of sugarcane bagasse particles, using appropriate equipment. Through the experiment is possible to determine the average diameter of particles pomace typical sugarcane mill. The equipment used for the grading sieve separation assembly consists of several dimensions, arranged vertically and which shows adequate for good separation from the pulp. Later, it makes immediate analysis for the determination of moisture, ash, volatile materials and fixed carbon. The study also determines the gross calorific value and allows analysis of densities of particles of sugar cane bagasse. Also studied the bagasse morphology using electron microscopes, where it was possible to visualize the geometry of the particles of bagasse. The use of Electronic Scanning Microscopy (SEM) provided better understand the morphology and particle size measured by using photography methods. Two methods for determining the sphericity of the particles were also used. The experiments carried out using appropriate standards and specific equations, allowing compare the present results with the values found by several researchers. Subsequently, fluid dynamic simulations were performed for the determination of porosity and minimum fluidization velocity theoretical. It follows that the sphericity and porosity of the bagasse particles influence the minimum fluidization velocity of biomass
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Pós-graduação em Engenharia Civil - FEIS
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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The use of digesters has become an important alternative for the proper disposal of organic agricultural wastes, serving as a solution to some environmental and health problems. Furthermore, the process of digestion provides commercially valuable by products such as biogas and bio fertilizer. The generation of biogas from agricultural waste, and its use in power generation systems has aroused great interest in rural areas because it enables supply in whole or in large part the energy demand of ownership by reducing production costs. The advent of technology has brought new forms of energy conversion of biogas, as the use of micro turbines specifies to be fuelled with biogas derived from the decomposition of organic matter in digesters, since it has a low level of methane in its composition, and high degree of impurities such as hydrogen sulphide, which are harmful to equipment and reduce the calorific value of biogas. The use of micro turbines behind other advantages like low emissions, great fuel flexibility and low maintenance. This paper presents an analysis of the feasibility of using biogas generated from cattle manure in micro turbines to generate electricity. Behind also an assessment of the energy potential that each animal has on various uses of biogas, and forms of energy recovery from the exhaust gases of the micro turbine. Also conducts an evaluation of the energy savings that the use of biogas aggregates properties.
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One of the energy alternatives that provide utility, flexibility, cleanliness and economy is biomass, such as forest waste (wood) and agricultural (sugarcane bagasse, rice husks, coffee pods, etc.). However, with its increasing supply and use grows also the concern of industries to invest in monitoring and control of emissions into the atmosphere, because during biomass burning are emitted as exhaust gases, fine particles known as particulates, which greatly contribute to the triggering of serious health problems to humans, in addition to the environmental damage. With that, this work aimed to conduct a monitoring of particulate and gaseous pollutants emissions to the atmosphere from the burning of various types of biomass used by industries. The equipment used for sampling were the optical monitor DataRAM 4 and the Unigas3000 + gas sampler. The results showed that biomass coffee pods presented the greatest concentration of particulates (485119 μg m-3) with particle diameters between 0.0602 μm and 0.3502 μm, i.e. the most ultrafine particles, harmful to human health and the environment. The largest emissions of CO and NOx were observed, respectively, for the coffee pods (3500 ppm) and for the rice husk (48 ppm). As for the superior calorific value (PCS), the best of fuel, with higher PCS, was the Eucalyptus grandis.
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There is a great global concern about the depletion and the high cost of fossil fuel reserves exploitation, more than ever, it is necessary to make a profound study and take advantage of alternative sources that can be used as energy efficiency with an appropriate pricing and low environmental impact. Brazil, which has highlighted using alternative energy sources as the use of ethanol and, in recent years, has been encouraging the expansion of its energy matrix in which the biodiesel will have a strategic importance within the agrobusiness area. Biodiesel is a fuel that can replace the diesel, which is a petroleum derivative. It is an ester, produced in the transesterification reaction of vegetable oils and animal greases, in an alcohol with an additional catalyst, are converted into fatty acids and result in esters with glycerol as sub products. The objective of this study was to estimate the final energy balance for the process biodiesel production from oil chicken waste. The energy balance estimation was quantified in calorific value according to the energy expenditure by calorimetric bomb method. The relationship between input and output of energy was around 0.97. In a first evaluation, the procedures adopted should be improved enough, so the process can become energetic and economically viable.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Il presente lavoro di tesi è frutto di una collaborazione fra il Dipartimento di Chimica Fisica ed Inorganica (gruppo del Prof. Valerio Zanotti – Mattia Vaccari, Dr. Rita Mazzoni) ed il Dipartimento di Chimica Industriale e dei Materiali (gruppo del Prof. Angelo Vaccari – Dr. Thomas Pasini, Dr. Stefania Albonetti, Prof. Fabrizio Cavani) e si inserisce il un progetto volto a valutare l’attività e la selettività del catalizzatore di idrogenazione di Shvo 1, verso l’idrogenazione selettiva del doppio legame polare del 5-idrossimetilfurfurale (HMF) in fase omogenea. L’HMF è un composto di natura organica facilmente ottenibile dalle biomasse, il quale può essere impiegato come building block per ottenere prodotti ad alto valore aggiunto per la chimica fine o additivi per biocarburanti aventi un elevato potere calorifico. In particolare la nostra attenzione si è rivolta alla produzione del 2,5-diidrossimetilfurano (BHMF), un importante building block per la produzione di polimeri e schiume poliuretaniche. Il lavoro di tesi da me svolto ha riguardato la messa a punto di una nuova metodologia sintetica per la preparazione del catalizzatore di Shvo e lo studio della sua attività catalitica nella riduzione di HMF a BHMF. Il comportamento del catalizzatore è stato monitorato studiando la resa in BHMF in funzione di tutti i parametri di reazione: temperatura, pressione di H2, solvente, rapporto molare substrato/catalizzatore, concentrazione, tempo. Successivamente è stata valutata la possibilità di riciclare il catalizzatore recuperando il prodotto di estrazione con acqua, per precipitazione o eseguendo la reazione in miscela bifasica (toluene/H2O). The present work is a collaboration between the Department of Physics and Inorganic Chemistry (group of Prof. Valerio Zanotti - Mattia Vaccari, Dr. Rita Mazzoni) and the Department of Industrial Chemistry and Materials (Group of Prof. Angelo Vaccari - Dr. Thomas Pasini, Dr. Stefania Albonetti, Prof. Fabrizio Cavani), and it’s a project devoted to evaluate the activity and selectivity of the Shvo catalyst, in the selective hydrogenation of polar double bond of 5 -hydroxymethylfurfural (HMF) in homogeneous phase. The HMF is an organic compound easily obtained from biomass, which can be used as a building block for fine chemicals abd polymer production or additives for biofuels with a high calorific value. In particular, our attention turned to the production of 2.5-bishydroxymethylfuran (BHMF), an important building block for the production of polymers and polyurethane foams. This thesis has involved the development of a new synthetic methodology for the preparation of Shvo’s catalyst and the study of its catalytic activity in the reduction of HMF to BHMF. The behavior of the catalyst was monitored by studying the yield in BHMF as a function of all the reaction parameters: temperature, pressure of H2, solvent, substrate to catalyst molar ratio, concentration, time. Subsequently it was evaluated the possibility of recycling the catalyst recovering the product of extraction with water, by precipitation or performing the reaction in biphasic mixture (toluene/H2O).
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With the introduction of the mid-level ethanol blend gasoline fuel for commercial sale, the compatibility of different off-road engines is needed. This report details the test study of using one mid-level ethanol fuel in a two stroke hand held gasoline engine used to power line trimmers. The study sponsored by E3 is to test the effectiveness of an aftermarket spark plug from E3 Spark Plug when using a mid-level ethanol blend gasoline. A 15% ethanol by volume (E15) is the test mid-level ethanol used and the 10% ethanol by volume (E10) was used as the baseline fuel. The testing comprises running the engine at different load points and throttle positions to evaluate the cylinder head temperature, exhaust temperature and engine speed. Raw gas emissions were also measured to determine the impact of the performance spark plug. The low calorific value of the E15 fuel decreased the speed of the engine along with reduction in the fuel consumption and exhaust gas temperature. The HC emissions for E15 fuel and E3 spark plug increased when compared to the base line in most of the cases and NO formation was dependent on the cylinder head temperature. The E3 spark plug had a tendency to increase the temperature of the cylinder head irrespective of fuel type while reducing engine speed.
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Sterile coal is a low-value residue associated to the coal extraction and mining activity. According to the type and origin of the coal bed configuration, sterile coal production can mainly vary on quantity, calorific value and presence of sulphur compounds. In addition, the potential availability of sterile coal within Spain is apparently high and its contribution to the local power generation would be of interest playing a significant role. The proposed study evaluates the availability and deployment of gasification technologies to drive clean electricity generation from waste coal and sterile rock coal, incorporating greenhouse gas emission mitigation systems, like CO2, H2S and NOx removal systems. It establishes the target facility and its conceptual basic design proposal. The syngas obtained after the gasification of sterile coal is processed through specific conditioning units before entering into the combustion chamber of a gas turbine. Flue gas leaving the gas turbine is ducted to a heat recovery steam generation boiler; the steam produced within the boilerdrives a steam turbine. The target facility resembles a singular Integrated Gasification in Combined Cycle (IGCC) power station. The evaluation of the conceptual basic design according to the power output set for a maximum sterile contribution, established that rates over 95% H2S and 90% CO2 removal can be achieved. Noticeable decrease of NOx compounds can be also achieved by the use of commercial technology. A techno-economic approach of the conceptual basic design is made evaluating the integration of potential unitsand their implementation within the target facility aiming toachieve clean power generation. The criterion to be compliant with the most restrictive regulation regarding environmental emissions is setting to carry out this analysis.
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O trabalho aborda a aplicação da técnica de reconciliação de dados para o balanço da movimentação de gás natural em uma malha de escoamento de gás não processado, elaborando também um método de cálculo rápido de inventário de um duto. Foram aplicadas, separadamente, a reconciliação volumétrica à condição padrão de medição e a reconciliação mássica, bem como realizadas comparações dos resultados em relação ao balanço original e verificação do balanço resultante de energia em termos de poder calorífico superior. Dois conjuntos de pesos foram aplicados, um arbitrado de acordo com o conhecimento prévio da qualidade do sistema de medição de cada um dos pontos, outro baseado no inverso da variância dos volumes diários apurados no período. Ambos apresentaram bons resultados e o segundo foi considerado o mais apropriado. Por meio de uma abordagem termodinâmica, foi avaliado o potencial impacto, ao balanço, da condensação de parte da fase gás ao longo do escoamento e a injeção de um condensado de gás natural não estabilizado por uma das fontes. Ambos tendem a impactar o balanço, sendo o resultado esperado um menor volume, massa e energia de fase gás na saída. Outros fatores de considerável impacto na qualidade dos dados e no resultado final da reconciliação são a qualidade da medição de saída do sistema e a representatividade da composição do gás neste ponto. O inventário é calculado a partir de uma regressão que se baseia em um regime permanente de escoamento, o que pode apresentar maior desvio quando fortes transientes estão ocorrendo no último dia do mês, porém a variação de inventário ao longo do mês possui baixo impacto no balanço. Concluiu-se que a reconciliação volumétrica é a mais apropriada para este sistema, pois os dados reconciliados levam os balanços mássicos e de energia em termos de poder calorífico, ambos na fase gás, para dentro do perfil esperado de comportamento. Embora um balanço volumétrico nulo apenas da fase gás não seja por si só o comportamento esperado quando se considera os efeitos descritos, para desenvolver um balanço mais robusto é necessário considerar as frações líquidas presentes no sistema, agregando maior dificuldade na aquisição e qualidade dos dados.