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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Determination of element composition in CoffeeBricks before and after incineration

Fröling, Annika January 2015 (has links)
The purpose for this study was to determine the element composition in CoffeeBricks before and after incineration. The difference between element composition in CoffeeBricks (barbecue briquettes made out of spent coffee grounds) and regular barbecue briquettes was also evaluated in this study. Aqua regia digests from the ash residues of CoffeeBricks and the ash residues of regular barbecue briquettes were analyzed with Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). H2SO4/H2O2 digests from unburned CoffeeBricks and plain spent coffee grounds were also analyzed with ICP-AES in order to evaluate the concentration for selected elements before and after incineration. The chosen elements evaluated in this study had concentrations higher than 0.1 ppm in the measured samples according to the ICP-AES analyses. Element concentrations are presented as mg trace element/g ashes or mg trace element/g sample. The ash residues of regular barbecue briquettes contained higher concentration of Al, Ca, Fe, Mg and S.The ash residues of CoffeeBricks contained higher concentration of B, Cu, Fe, K, Mn, Na and P. One-way ANOVA showed that there were differences in concentration for the elements Ca, K, P, Na and S between the ash residues of the two different types of CoffeeBricks and regular barbecue briquettes for <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Calpha" />=0.001. One-way ANOVA also showed differences in concentration for the elements Ca, K, P and Na between the two different types of unburned CoffeeBricks and plain spent coffee grounds for <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Calpha" />=0.01.
2

A novel polymeric approach to the cold cure briquetting of anthracite/breeze fines

Thorns, Leisha Jane January 2001 (has links)
No description available.
3

Assessing Alternative Options for Energy Cost Reduction in Greenhouse Industry

Ravichandran, Prabahar 27 November 2013 (has links)
Nova Scotia has over 100 commercial greenhouses covering an area of 186,245 square meters. Heating costs have become the largest energy expenditure in greenhouses mainly due to increasing fuel prices and the use of imported fuel oils. Increasing fuel prices combined with a growing desire to stabilize energy supply has led to a renewed interest in alternative fuel options for greenhouse heating. Agricultural or herbaceous biomass has the potential to become a sustainable and cost effective heating option for the greenhouse industry. Although high inorganic content create challenges during the combustion of herbaceous biomass, these crops create an opportunity if sufficient land mass is available for greenhouse growers to meet their own fuel needs. This research will review energy use and operational practices in the greenhouse industry to identify energy saving opportunities. This study will further investigate biomass feedstocks, processing and combustion technologies suitable for heating greenhouse industry in Nova Scotia.
4

Caracterização química e energética de briquetes produzidos com rejeitos de resíduos sólidos urbanos e madeira de Eucaliptus grandis

Gonçalves, José Evaristo [UNESP] 31 August 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:24:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-08-31Bitstream added on 2014-06-13T19:52:12Z : No. of bitstreams: 1 goncalves_je_me_botfca.pdf: 483623 bytes, checksum: f004f54f7b1193eeb66d09f89718f0fa (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Universidade Estadual Paulista (UNESP) / Este trabalho avalia técnica e ambientalmente o uso de briquetes para a geração de energia. Os materiais utilizados para a fabricação dos briquetes foram Rejeitos de Resíduos Sólidos Urbanos (RRSU) com resíduos madeireiros Eucalyptus grandis. As amostras dos RRSU foram coletadas na Usina de Reciclagem e Compostagem de Lixo de Lençóis Paulista, atualmente descartados em aterro sanitário municipal e os resíduos madeireiros em serrarias do município de Botucatu-SP. Esse estudo objetivou gerar alternativas para minimizar a quantidade de material destinado aos aterros com responsabilidade social e ambiental. Os briquetes foram fabricados com 0, 5, 10, 15, 20 e 25% de RRSU na mistura com resíduos madeireiros. Os resultados da análise do Poder Calórico Superior (PCS) realizadas nos briquetes mostraram que o valor do PCS aumenta na medida em que a porcentagem dos RRSU aumentado. Briquetes de resíduos de madeira apresentaram Poder Calórico Inferior (PCI) de 18135,68 kJ/kg, valor significativamente menor ao encontrado para briquetes com 25% RRSU, o qual foi de 19860,00 kJ/kg. Essa mesma tendência foi verificada para todos os briquetes estudados. O fato anterior se deve a influência dos produtos derivados do petróleo que estão presentes nos RRSU, como por exemplo, os termoplásticos, os quais tem PCS médio na ordem de 34039,67 kJ/kg. A briquetagem dos materiais foi realizada com o material... / This research project evaluates technique and ambient the use of blend of briquettes for the generation of energy. The materials used for the production of the blend were Reject of Urban Solid Residues - RRSU and residues lumbermen (Eucalyptus grandis). The samples of RRSU were collected in the Plant of Recycling and Compossite of Garbage of Sheets From São Paulo, now discarded in municipal sanitary embankments and the residues lumbermen in sawmills of the municipal district of Botucatu-SP, material of great readiness in the area. That study, lens to generate alternatives to minimize the amount of material destined to the embankments with social and environmental responsibility. Briquettes were manufactured with 0, 5, 10, 15, 20 and 25% of RRSU in the mixture with residues lumbermen. The results of the analysis of the Superior Caloric Power - PCS accomplished to the briquettes, they showed that PCS increases in the measure in that the percentage of RRSU is larger. Briquettes of wood residues, presented to Can Caloric Inferior - PCI of 18135,68 kJ/kg, value significantly smaller to the found for briquettes with 25% RRSU, which was of 19860,00 kJ/kg. That same tendency was verified for all of the studied blend. The previous fact is due influences her/it of the derived products of the petroleum that are present in RRSU, as they are the plastics, which he/she has a PCS in the order of 34039,67 kJ/kg. The briquetagem of the blendas was accomplished with the material containing 12% of humidity, being obtained briquettes visually little resistant and brittle. That result can be improved adjusting the conditions of operation of the machine of such 4 briquetting as: the pressure and the temperature. It is also necessary to research the effect of the percentage of RRSU on the mechanical resistance of the briquettes. Analyses of Gaseous Cromatografy... (Complete abstract, click electronic access below)
5

Estudo tecnico-economico da compactação de residuos madeireiros para fins energeticos / Technical and economic study of wood residues compression for energy use

Silva, Claudinei Augusto da 27 February 2007 (has links)
Orientador: Jose Dilcio Rocha / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-09T06:17:35Z (GMT). No. of bitstreams: 1 Silva_ClaudineiAugustoda_M.pdf: 937524 bytes, checksum: 782eb3844cc3324386d1ce6f150a540b (MD5) Previous issue date: 2007 / Resumo: O objetivo central deste trabalho foi o de demonstrar os processos de compactação de resíduos de biomassa visando à substituição de combustíveis tradicionais, como a lenha e os combustíveis fósseis. Foi estudada a viabilidade técnico-econômica da implantação de uma fábrica de compactação de resíduos madeireiros com capacidade anual de 2.112 toneladas de briquetes ou pellets para fins energéticos. Foram simulados quatro cenários diferentes, visando um estudo mais próximo da realidade. Em cada cenário foram analisados os investimentos fixos e tangíveis e as estruturas de custos operacionais para a implantação de uma fábrica de compactação de resíduos madeireiros. Na simulação dos cenários, foram empregados diferentes valores para o preço da matéria-prima e a incidência de impostos na venda do produto. O estudo de viabilidade técnico-econômica baseou-se em dados reais, disponibilizados por uma empresa madeireira de médio porte. O processo e a utilização de briquetes e pellets no comércio, que pode abrir novas possibilidades, principalmente no setor comercial, foram avaliados. Os processos tradicionais de compactação também foram analisados. Mostrou-se que o processo de compactação de resíduos madeireiros é economicamente viável desde que o custo da matéria-prima não ultrapasse R$ 42,00 por tonelada. Outra forma de tornar o processo economicamente viável é a redução nos impostos incidentes sobre a venda do produto. Através deste estudo ficou clara a incidência de alta carga tributária, um aspecto econômico típico da economia brasileira / Abstract: The main purpose of this work is to demonstrate the biomass compression processes for the substitution of traditional fuels such as wood and fossil fuels. It was performed a technical and economic feasibility analysis of the deployment of a wood residue compression plant with a yearly capacity of 2,112 tons of briquettes or pellets for energy use. Four different scenarios were created as close to reality as possible. In each scenario, intangible and tangible investments and operating costs were analyzed for the deployment of a wood residue compression plant. In addition, different prices of raw material and different sales tax were also used. The technical and economic feasibility study was based on actual data made available by a Brazilian mediumsized company in the woodworking industry. The manufacturing process and commercial use of briquettes and pellets, which can open new possibilities for the commercial sector, were assessed. Traditional compression processes were also evaluated. The study showed that the wood residue compression process is economically feasible if the cost of raw material does not exceed R$42.00 per ton. The process would also be economically feasible if sales taxes dropped. This work clearly demonstrated that high taxes, a typical component in the Brazilian economy, are a significant barrier to wood residue compression processes / Mestrado / Mestre em Planejamento de Sistemas Energéticos
6

Sustainable Energy Model for the production of biomass briquettes based on rice husk in low-income agricultural areas in Peru.

Arévalo, Juan, Quispe, Grimaldo, Raymundo, Carlos 12 1900 (has links)
The proposed Sustainable Energy Model is based on rice husk and the development of briquettes made from agricultural waste, which will increase efficiency in the domestic sector, and potentially replace conventional polluting fuels such as firewood. Large volumes of rice husks from millers are found scattered in rural agricultural areas of the San Martin region of Peru, where people are exposed daily to the emissions of polluting gases produced by burning these wastes, causing respiratory and lung diseases. Despite present circumstances, this waste has a great energetic potential that is not yet used by society, representing an opportunity to encourage socioenvironmental development and generate added value to the husk. Based on a compaction and drying process, briquettes were obtained with 4,040 kcal / kg of heat power and 80.39% combustion efficiency, allowing the little use of biofuel compared to firewood, and consequently, the utilization of this biofuel would reduce levels of deforestation. In contrast to similar projects, the sustainability of an energetic model of briquette production will be achieved when economic, environmental and social aspects are met, developing clean technologies and an efficient supply chain, from the supply of the husk to the commercialization of briquettes
7

Biomass Briquettes in Malawi

Faxälv, Olle, Nyström, Olof January 2007 (has links)
<p>In Malawi 2.5 % of the forest disappears each year. The use of firewood and charcoal, deriving from forest resources,</p><p>accounts for about 99 % of the household energy demand in Malawi and is a cause to the deforestation. The Government of</p><p>Malawi recently launched a programme called Promotion of Alternative Energy Sources Programme (PAESP) with the aim</p><p>to reduce the use of firewood and charcoal. One of the fuels included in the programme is the biomass briquette. The aim</p><p>with this study is to evaluate the viability of biomass briquettes as a sustainable alternative energy source to firewood and</p><p>charcoal for households in Malawi.</p><p>Research for the study was carried out during three months in Malawi. Visits were made to a number of briquette</p><p>production sites to study the manufacturing methods and to collect briquette samples. The briquettes were tested using</p><p>various methods and then compared with results for firewood and charcoal.</p><p>At the moment various production methods are used in Malawi, with a high difference in technical complexity and cost.</p><p>Machines produced from wood using very basic mechanics can apply similar pressure as more advanced metal pressers.</p><p>They also seem to be better suited than those made of metal, in terms of price and availability.</p><p>The majority of the briquette producers in Malawi use waste paper as base material. Although the paper briquettes are good,</p><p>other raw materials will be needed if the production is supposed to be significantly increased.</p><p>The briquettes burn well using the most common stoves in Malawi, including the commonly used charcoal stove. While</p><p>firewood is cheaper to use than other available fuels, the briquettes seem to be able to compete with the fuel costs for</p><p>charcoal.</p>
8

Biomass Briquettes in Malawi

Faxälv, Olle, Nyström, Olof January 2007 (has links)
In Malawi 2.5 % of the forest disappears each year. The use of firewood and charcoal, deriving from forest resources, accounts for about 99 % of the household energy demand in Malawi and is a cause to the deforestation. The Government of Malawi recently launched a programme called Promotion of Alternative Energy Sources Programme (PAESP) with the aim to reduce the use of firewood and charcoal. One of the fuels included in the programme is the biomass briquette. The aim with this study is to evaluate the viability of biomass briquettes as a sustainable alternative energy source to firewood and charcoal for households in Malawi. Research for the study was carried out during three months in Malawi. Visits were made to a number of briquette production sites to study the manufacturing methods and to collect briquette samples. The briquettes were tested using various methods and then compared with results for firewood and charcoal. At the moment various production methods are used in Malawi, with a high difference in technical complexity and cost. Machines produced from wood using very basic mechanics can apply similar pressure as more advanced metal pressers. They also seem to be better suited than those made of metal, in terms of price and availability. The majority of the briquette producers in Malawi use waste paper as base material. Although the paper briquettes are good, other raw materials will be needed if the production is supposed to be significantly increased. The briquettes burn well using the most common stoves in Malawi, including the commonly used charcoal stove. While firewood is cheaper to use than other available fuels, the briquettes seem to be able to compete with the fuel costs for charcoal.
9

Desenvolvimento de briquetes autorredutores a partir de carepas de processamento siderúrgico para utilização em forno elétrico a arco

Buzin, Pedro Jorge Walburga Keglevich de January 2009 (has links)
A indústria siderúrgica do Estado do Rio Grande do Sul é do tipo semi-integrada e produz aço a partir de sucata, utilizando fornos a arco elétrico. Em suas atividades gera vários tipos de resíduos, dentre estes as carepas, cujo componente principal são óxidos de ferro. Este material não encontra utilização e geralmente tem destinação final em aterros de resíduos industriais ou co-processamento em fábricas de cimento. A produção e o processamento do carvão vegetal no estado do Rio Grande do Sul também geram como principal resíduo uma fração de baixa granulometria constituída de finos de carvão vegetal que praticamente não tem utilização e é descartada no meio ambiente. O objetivo do presente trabalho é buscar uma solução para a reciclagem de carepas geradas em usinas semi-integradas dentro do próprio processo produtivo. A solução proposta foi o desenvolvimento de um briquete autorredutor elaborado com carepa de aciaria e finos de carvão vegetal, com possibilidade de utilização na carga do forno elétrico à arco. Carepas e finos de carvão vegetal foram coletados e caracterizados. Briquetes autorredutores foram feitos com estes materiais e submetidos a ensaios de redução nas temperaturas de 1100, 1200 e 1260°C. O comportamento dos briquetes em altas temperaturas foi qualitativamente avaliado. Cálculos matemáticos e simulação computacional foram utilizados numa estimativa do consumo energético destes briquetes. O desempenho dos briquetes e os resultados obtidos permitem concluir pela potencialidade de utilização destes briquetes autorredutores como parte da carga de fornos elétricos a arco. / The steelmaking industry in Rio Grande do Sul State is semi-integrated and produces steel from scrap metal using electric arc furnaces. In its activities generates several wastes, among them mill scale, which main component are iron oxides. This material does not have use and generally have final destination in industrial landfills or co-processing in cement plants. The production and processing of charcoal in Rio Grande do Sul State also generate as main waste a fraction of low granulometry, consisting of charcoal fines what practically have no use and is disposal in the environment. The objective of the present work is to look for a solution to mill scale recycling, generated in semi-integrated steelmaking plants, inside its own productive process. The proposed solution was the development of self-reducing briquette produced with mill scale and charcoal fines, with possibilities of use in charge of electric arc furnace. Mill scale and charcoal fines were collected and characterized. Self-reducing briquettes were made from these materials and subjected to tests of reduction at temperatures of 1100, 1200 and 1260°C. The behaviour of briquettes in high temperatures was qualitatively evaluated. Mathematical calculation and computational simulation were used in a estimative of the energetic consumption of these briquettes. The performance of briquettes and the obtained results allow to conclude the potential use of these self-reducing briquettes as a part of charge in electric arc furnaces.
10

Avaliação do potencial energético de resíduos de produção agrícola provenientes do beneficiamento da mandioca e do milho / Assessment of energy potential of agricultural production obtained from the processing of manioc and corn

Alves, Darline Albuquerque de Holanda 28 April 2014 (has links)
Brazil is privileged with respect to the variety of agricultural and forestry crops, depending on the climate and also the good soil conditions country, and has a huge expanse of land available for cultivation of various plant species. This potential producer generates a huge amount of waste, both from agricultural activities as the timber. Such debris can, in most cases, cause environmental degradation. The use of alternative sources of energy to fossil fuels has been gaining prominence in Brazil and worldwide. An option to prevent the depletion of natural resources is to replace the wood in the ovens by direct burning of agricultural waste from this activity or other waste in nature. The existing agricultural biomass in Brazil is from different cultures, for example, corn and manioc. The work aims to quantify and characterize the agroindustrial waste from cassava and maize throughout the State of Alagoas, aiming its use for burning in furnaces flour mills of the wild region. Physicochemical analysis of the raw material fresh and briquette form were conducted primarily to assess the calorific value of the samples, and all analyzes were performed according to the ABNT. It were obtained for the samples in nature, calorific value of 16.79 MJ/kg for cassava peels, 19.00 MJ/kg for manioc, 19.17 MJ/kg for corncobs and 18.58 MJ/kg in maize straw. The briquettes samples had a slight decrease in the calorific value, with 16.73 MJ/kg, 18.89 MJ/kg, 18.92 MJ/kg and 18.44 MJ/kg of values obtained for cassava peels, manioc, corncobs and maize straw, respectively. Still, it can be observed that both the waste from the processing of cassava as the corn had relevant potential energy when compared to firewood, around 20.70 MJ/kg, being able to be a substitute for wood, both in commercial as environmental aspect. / O Brasil é um país privilegiado no que diz respeito à variedade de culturas agrícolas e florestais, em função do clima e, também, das boas condições do solo, além de dispor de uma enorme extensão de terra disponível ao cultivo de várias espécies vegetais. Esse potencial produtor gera uma enorme quantidade de resíduos, tanto provenientes de atividades agrícolas quanto de madeireiras. Tais detritos podem, na maioria das vezes, causar a degradação do meio ambiente. A utilização de fontes de energia alternativas aos combustíveis fósseis vem ganhando destaque no Brasil e no mundo. Uma opção para evitar o esgotamento dos recursos naturais seria a substituição da lenha nos fornos pela queima direta de resíduos agrícolas provenientes desta atividade ou de outros resíduos in natura. As biomassas agrícolas existentes no Brasil são oriundas de diversas culturas, como, por exemplo, a do milho e a da mandioca. O trabalho propõe quantificar e caracterizar os resíduos agroindustriais provenientes da mandioca e do milho no Estado de Alagoas, visando seu uso para a queima nos fornos de casas de farinha da região do agreste. Foram realizadas análises físico-químicas da matéria-prima in natura e briquetada, principalmente para avaliar o poder calorífico das amostras, sendo todas as análises realizadas de acordo com as normas da ABNT. Obtiveram-se, para as amostras in natura, poder calorífico para a casca da mandioca de 16,79 MJ/kg, 19,00 MJ/kg para a maniva, 19,17 MJ/kg para o sabugo do milho e 18,58 MJ/kg para palha do milho. As amostras briquetadas tiveram ligeiro decréscimo do poder calorífico, sendo 16,73 MJ/kg, 18,89 MJ/kg, 18,92 MJ/kg e 18,44 MJ/kg os valores obtidos para a casca da mandioca, maniva, sabugo do milho e palha do milho, respectivamente. Ainda assim, pode-se observar que tanto os resíduos provenientes do beneficiamento da mandioca quanto os do milho apresentaram relevante potencial energético quando comparamos ao da lenha, em torno de 20,70 MJ/kg, sendo passíveis de serem substitutos à lenha, tanto no aspecto comercial quanto ambiental.

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