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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.
11

Investigation of spontaneous combustion phenomenology of bagasse and calcium hypochlorite / Spontaneous combustion of bagasse and calcium hypochlorite

Halliburton, Brendan William January 2002 (has links)
Thesis (PhD)--Macquarie University, Division of Environmental and Life Sciences, Department of Chemistry, 2002. / Bibliography: leaves 234-240. / Introduction, theoretical descriptions of spontaneous combustion phenomena and aims of this thesis -- Laboratory measurements of the self-heating phenomenology of bagasse -- Field experiments investigating the self-heating behaviour of large scale stockpiles of low symmetry -- Self-heating and thermal ignition of calcium hypochlorite -- Experimental methods and procedures used for the critical ambient temperature of HCH -- Results of critical ambient temperature measurements upon single containers of hydrated high strength HCH -- Experiments on the interaction of self-heating drums -- Conclusions. / The hazard of spontaneous combustion is a problem that confronts any industry that transports or stores a reactive material. Bagasse is a reactive material that presents an expensive spontaneous combustion hazard for the sugar industry since this material is the principal fuel used at sugar mills. Calcium Hypochlorite is another such material presenting a significant industrial spontaneous combustion hazard for the transport and insurance industry as it has been linked to a number of expensive maritime conflagrations. The investigation of fundamental self-heating phenomenon is critical for the understanding, control and prevention of spontaneous ignition with these materials. -- By way of isothermal calorimetry techniques and fundamental thermal ignition measurements, this study has provided improved understanding into the oxidative self-heating phenomenology of bagasse and thermal ignition phenomenology of calcium hypochlorite. Both substances have been shown to possess unusual and previously unknown self-heating behaviour at temperatures below 100°C, with water being a principal component of each mechanism. -- The outcomes of this study have provided a platform which has enabled current mathematical models to predict large scale self-heating phenomena for industrially stored quantities of these materials. / Mode of access: World Wide Web. / 240 leaves, bound ill
12

Measuring, modelling and understanding the mechanical behaviour of bagasse

Plaza, Floran January 2002 (has links)
In the Australian sugar industry, sugar cane is smashed into a straw like material by hammers before being squeezed between large rollers to extract the sugar juice. The straw like material is initially called prepared cane and then bagasse as it passes through successive roller milling units. The sugar cane materials are highly compressible, have high moisture content, are fibrous, and they resemble some peat soils in both appearance and mechanical behaviour. A promising avenue to improve the performance of milling units for increased throughput and juice extraction, and to reduce costs is by modelling of the crushing process. To achieve this, it is believed necessary that milling models should be able to reproduce measured bagasse behaviour. This investigation sought to measure the mechanical (compression, shear, and volume) behaviour of prepared cane and bagasse, to identify limitations in currently used material models, and to progress towards a material model that can predict bagasse behaviour adequately. Tests were carried out using a modified direct shear test equipment and procedure at most of the large range of pressures occurring in the crushing process. The investigation included an assessment of the performance of the direct shear test for measuring bagasse behaviour. The assessment was carried out using finite element modelling. It was shown that prepared cane and bagasse exhibited critical state behaviour similar to that of soils and the magnitudes of material parameters were determined. The measurements were used to identify desirable features for a bagasse material model. It was shown that currently used material models had major limitations for reproducing bagasse behaviour. A model from the soil mechanics literature was modified and shown to achieve improved reproduction while using magnitudes of material parameters that better reflected the measured values. Finally, a typical three roller mill pressure feeder configuration was modelled. The predictions and limitations were assessed by comparison to measured data from a sugar factory.
13

Pressurised entrained flow gasification of sugar cane wastes for cogeneration /

Joyce, James Alexander. January 2006 (has links)
Thesis (Ph.D.) - University of Queensland, 2006. / Includes bibliography.
14

Comparative analysis of characteristics of the various sugarcane bagasse types in terms of gasification

Kula, Mpumezo January 2016 (has links)
The insight that the fossil fuel reserves are limited, together with concerns over security of supply (i.e. the oil crises), initiated the first raise of interest in biomass and all other renewable energy forms. However, the concern grew that global warming and the resulting climate change were enhanced by carbon dioxide (CO2) emissions resulting from fossil fuel consumption. Meanwhile, biomass energy is thought to account for 14–15% of total world energy consumption. Hence, the exploitation and utilization of biomass energy are effective and necessary for relieving the pressures caused by environmental pollution and fossil fuel shortage (Lv et al., 2010). Recently, extensive research aimed at converting biomass to useful energy have been carried out, especially pyrolysis and gasification, which are particularly suitable for the effective and efficient utilization of biomass. Sugarcane bagasse is the main byproduct of sugarcane mill, ready available at the production site so that it may be a suitable raw material for the production of biofuels, chemicals, and electricity. Among the methods that have been previously studied, is this particular study we explore thermochemical process, gasification. The properties of sugarcane bagasse relevant to gasification are briefly reviewed. The compositions of the bagasse as a fuel are variable, especially with respect to inorganic constituents important to the critical problems of sintering, fouling and slagging. Alkali and alkaline earth metals, in combination with other fuel elements such as silica and sulfur, are responsible for many undesirable reactions in a gasifier system.
15

Efeito dos pré-tratamentos químicos e físicos do bagaço de cana-de-açúcar na hidrólise enzimática

Grimaldi, Maira Prearo [UNESP] 28 January 2013 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-01-28Bitstream added on 2014-06-13T19:29:03Z : No. of bitstreams: 1 grimaldi_mp_me_araiq_parcial.pdf: 397509 bytes, checksum: 91466dd572d891d79bdae0f996816cc4 (MD5) Bitstreams deleted on 2015-06-25T13:01:13Z: grimaldi_mp_me_araiq_parcial.pdf,. Added 1 bitstream(s) on 2015-06-25T13:03:29Z : No. of bitstreams: 1 000718750_20151228.pdf: 377997 bytes, checksum: 2ceb3dbd9e7586bfb090803cd431a997 (MD5) Bitstreams deleted on 2016-01-04T10:26:27Z: 000718750_20151228.pdf,. Added 1 bitstream(s) on 2016-01-04T10:28:18Z : No. of bitstreams: 1 000718750.pdf: 1307772 bytes, checksum: 2ee8c12de98eb0b30c7b60feb815bf1e (MD5) / Com a crescente demanda por fontes alternativas de combustíveis, a produção de etanol a partir de materiais lignocelulósicos torna-se uma opção interessante. Esse processo permite o aumento da produção de etanol sem a necessidade de crescimento da área plantada dos cultivares utilizados. Para a produção do etanol celulósico é necessário o fracionamento da biomassa de forma a disponibilizar a maior quantidade de carboidratos possível para o processo de fermentação alcoólica, porém essa biomassa precisa de um pré-tratamento para desorganizar a estrutura recalcitrante do material. Neste sentido, o principal objetivo deste projeto foi avaliar os métodos de pré-tratamentos alcalino, utilizando hidróxido de cálcio, e hidrotérmico, utilizando água, nos bagaços de cana-de-açúcar in natura (obtido diretamente da moenda) e explodido (submetido a explosão a vapor). Foram testados os tempos de 7, 30 e 60 minutos em ambos os tratamentos a uma temperatura de 120 °C em autoclave. Foram realizados planejamentos fatoriais completos a fim de analisar a influência do hidróxido de cálcio e do tempo no desempenho da hidrólise, quantificando a liberação de glicose e açúcares redutores totais (ART). Dessa maneira foram realizadas análises da composição química do bagaço pré-tratado a fim de avaliar uma possível correlação entre as modificações na estrutura do material e a eficiência da hidrólise. Os resultados mostraram que os melhores rendimentos foram obtidos com o bagaço in natura pré-tratado com hidróxido de cálcio em todos os tempos testados, a hidrólise enzimática desse material resultou em um rendimento mais alto, de 3,2 a 4,3 vezes, em comparação com a hidrólise no bagaço in natura sem pré-tratamento. Um novo planejamento foi realizado, delineamento composto central superfície resposta, para determinar as... / Due to the growing demand for alternative sources of fuel, ethanol production from lignocellulosic materials became an interesting option. This process allows the increase of ethanol production without the need of growth of the planted area of the cultivars used. For the production of cellulosic ethanol is necessary to fractionate the biomass to provide the largest possible amount of carbohydrates to ethanol fermentation process, but this biomass needs a pretreatment to disrupt the recalcitrant structure of the material. In this sense, the main objective of this project was to evaluate the methods of alkaline pretreatments, using calcium hydroxide, and hydrothermal ,using water, in sugar cane bagasses in natura (obtained directly from the mill) and exploded (subjected to steam explosion). We tested different times (7, 30 and 60 minutes) in both treatments at a temperature of 120 °C in autoclave. Complete factorial designs were performed to examine the influence of calcium hydroxide and hydrolysis time performance by quantifying the release of glucose and total reducing sugars (TRS). Thus were analyzed the chemical composition of the pretreated bagasse to evaluate a possible correlation between changes in material structure and efficiency of hydrolysis. The results showed that the best yields were obtained with the in natura bagasse pretreated with calcium hydroxide at all times tested and the enzymatic hydrolysis increased from 3.2 to 4.3 fold compared to untreated in natura bagasse. A new schedule was conducted, a central composite design surface response, to determine the hydrolysis conditions which lead to maximal glucose release. In this step was done the hydrolysis of in natura bagasse subjected to alkaline pretreatment, with the addition of a nonionic surfactant (Tween 80). The best condition found in this optimization... (Complete abstract click electronic access below)
16

Linhagens fúngicas na hidrólise enzimática de bagaço de cana-de-açúcar

Rabonato, Aline Cristina [UNESP] 29 July 2013 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:24:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-07-29Bitstream added on 2014-06-13T18:52:32Z : No. of bitstreams: 1 rabonato_ac_me_botfca.pdf: 701073 bytes, checksum: 0b8419eb4d8b3409bea93742802fc3aa (MD5) / A produção de bioetanol e de açucares a partir do caldo de cana gera como um dos subprodutos, o bagaço. Atualmente, esse último, uma biomassa industrial lignocelulósica, pode ser aproveitado para produção de etanol de segunda geração, desde que previamente submetido a processos hidrolíticos para gerar açúcares fermentescíveis. O objetivo deste trabalho foi estimar a produção de bioetanol a partir desta biomassa agroindustrial. Para tanto, foram utilizados os cogumelos Lentinula edodes, Pleurotus ostreatus, Pleurotus eryngii e Pycnoporus sanguineus como potenciais fontes produtoras das enzimas lacase, manganês peroxidase e lignina peroxidase, capazes de hidrolisar o bagaço de cana-de-açúcar. As maiores atividades enzimática observadas para L. edodes, P. ostreatus, P. sanguineus e P. eryngii para lacase foram de 39,23 U-mL ao 25º dia de incubação, 2,5 U-mL e 80 U-mL ao 27º dia de incubação, e 16,45 U-mL ao 15º dia, respectivamente. As enzimas MnP e LiP não apresentaram resultados expressivos. A hidrólise enzimática do bagaço de cana in natura (32,17% de hemicelulose, 52,45% de celulose e 10,62% de lignina) e o bagaço de cana hidrolisado com H2SO4 7,0% (0,20% de hemicelulose, 68,82% de celulose e 25,33% de lignina) foram avaliados para cada conjunto enzimático obtido. Comparado aos demais, as enzimas produzidas pelo P. sanguineus incubado em bagaço in natura apresentaram uma melhor eficiência na conversão dos açúcares, com teor médio de 0,14 g-L de glicose. Embora os baixos teores de glicose determinada nesse trabalho, em relação com a literatura, pode-se afirmar que as enzimas lacase, manganês peroxidase e lignina peroxidase, demonstraram ter potencial hidrolítico, principalmente para as produzidas pelo fungo P. sanguineus / The production of ethanol and sugar from sugarcane juice bagasse is generate byproduct. Currently, the bagasse, an industrial lignocellulosic biomass can be used for production of second generation ethanol, since when submitted to hydrolytic processes generate fermentable sugars. The objective of this study was to estimate the production of bioethanol from this agro biomass. Lentinula edodes, Pleurotus ostreatus, Pleurotus eryngii and Pycnoporus sanguineus were used as potential sources producing enzymes laccase, manganese peroxidase and lignin peroxidase, capable of hydrolyzing the sugarcane bagasse. The highest activity of enzymes, observed for L. edodes, P. ostreatus, P. sanguineus and P. eryngii were to 39.23 U-mL laccase after 25 days of incubation, 2,5 U-mL and 80 U-mL after 27 days of incubation, and 16,45 U-mL on 15 day, respectively. MnP and LiP showed no significant results. The enzymatic hydrolysis of sugarcane bagasse in natura (32,17% hemicellulose, cellulose 52,45% and 10,62% lignin) and bagasse hydrolyzate with 7,0% H2SO4 (0,20% hemicellulose, 68,82% to 25,33% cellulose and lignin) were evaluated for each enzymatic obtained. Compared to others, the enzymes produced by P. sanguineus incubated in sugarcane bagasse showed better efficiency in getting glucose with an average grade of 0,14 g-L. Although low levels of glucose determined in this work, in relation to the literature, it can be stated that the enzymes laccase, manganese peroxidase and lignin peroxidase, demonstrated good hydrolytic potential, especially for those produced by the fungus P. sanguineus.
17

Determinação das condições ótimas de fermentação para produção de enzimas celulolíticas pelo fungo Aspergillus niger derivado-marinho, utilizando diferentes subprodutos agroindustriais

Marques, Marina Paganini [UNESP] 27 June 2014 (has links) (PDF)
Made available in DSpace on 2016-08-12T18:48:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-06-27. Added 1 bitstream(s) on 2016-08-12T18:50:50Z : No. of bitstreams: 1 000866164.pdf: 63682 bytes, checksum: ab402715b457ddfd406732d19931125e (MD5)
18

Enriquecimento nutricional de bagaço de uva através do crescimento de Aspergillus niger

Sganzerla, Edmar 20 October 2017 (has links)
o setor vitivinícola é responsável por 1% do Produto Interno Bruto (PIB) do Rio Grande do Sul, sendo o estado responsável por 90% da produção Brasileira de vinhos, cujo mercado é crescente. Na indústria vitícola cerca de 25% da quantidade processada de uva transforma-se em resíduos, representados principalmente por cascas, sementes e engaço. Este trabalho teve como objetivo analisar as características nutricionais de bagaço de Vitis sp e o seu enriquecimento com Aspergillus niger T0005/007-2. Foi verificado que a fermentação em estado sólido destes resíduos utilizando o fungo filamentoso A. niger eleva os teores de . proteína bruta de resíduos de uva, além do aumento do valor calórico, de carboidratos, fibra alimentar total, lipídios, e umidade. O incremento dos carboidratos 20 dias após a exposição ao fungo A. niger é um fator favorável para utilização do mesmo para ração animal, pois desta forma se torna a formulação mais adequada para uma complementação à ração de suínos. O crescimento de micélio do fungo A. niger, sobre resíduos de engaço de Vitis sp mostra-se promissor para o aumento do valor nutricional dos resíduos da produção de uva, que já vêm sendo utilizados na alimentação de alguns animais. Com base nesses resultados, a bioconversão do engaço da uva empregando fermentação em estado sólido com linhagens de A. niger pode ser um complemento para alimentação de animais (sic). / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2017-11-24T18:16:05Z No. of bitstreams: 1 Dissertacao Edmar Sganzerla.pdf: 16247252 bytes, checksum: 2a586b7329e98b4d5fcfd69172ad5046 (MD5) / Made available in DSpace on 2017-11-24T18:16:05Z (GMT). No. of bitstreams: 1 Dissertacao Edmar Sganzerla.pdf: 16247252 bytes, checksum: 2a586b7329e98b4d5fcfd69172ad5046 (MD5) Previous issue date: 2017-11-24 / The wine sector is responsible by 1% ofthe Gross Domestic Product (GDP) of Rio Grande do Sul, being the state responsible by 90% of the brazilian production of wines, which market is growing. In the wine industry, around 25% of the processed amount of grape turn's into waste, mainly represented by grape skins, seeds and stems. This work had the objective of analyzing the nutritional characteristics of Vitis sp stem's and its improvement with Aspergillus niger T0005/007-2. It was checked that the solid state fermentation of those wastes using the filamentous fungus A. niger increases the crude protein content of grape waste, besides the caloric value risement, of carbohydrates, total dietary fiber, lipids and moisture. The increment of the carbohydrates 20 days afier the exposition to the fungus A. niger is a favorable facto r to the usage for animal food, because in this way, the formulation it can be added to a swine's feed complementation. The implementation of fungus A. niger, into stem's Vitis sp wastes seems promissing to the nutritional value agregation over wastes of grape production that are already being used into the feed of some animals. Based on these results, the grape's stem bioconversion using the solid state fermentation method could be an alternative at animal's feeding (sic).
19

Determinação das condições ótimas de fermentação para produção de enzimas celulolíticas pelo fungo Aspergillus niger derivado-marinho, utilizando diferentes subprodutos agroindustriais /

Marques, Marina Paganini. January 2014 (has links)
Orientador: Sandra Regina Pombeiro Sponchiado / Co-orientador: Rubens Monti / Banca: Heloiza Ferreira Alves do Prado / Banca: Luis Henrique Souza Guimarães / Banca: Sarita Candida Rabelo / Banca: Sandra Helena Cruz / Resumo: Não disponível. / Abstract: Not available. / Doutor
20

Efeito dos pré-tratamentos químicos e físicos do bagaço de cana-de-açúcar na hidrólise enzimática /

Grimaldi, Maira Prearo. January 2013 (has links)
Orientador: Sandra Regina Pombeiro Sponchiado / Banca: Rubens Monti / Banca: Célia Maria Araújo Galvão / Resumo: Com a crescente demanda por fontes alternativas de combustíveis, a produção de etanol a partir de materiais lignocelulósicos torna-se uma opção interessante. Esse processo permite o aumento da produção de etanol sem a necessidade de crescimento da área plantada dos cultivares utilizados. Para a produção do etanol celulósico é necessário o fracionamento da biomassa de forma a disponibilizar a maior quantidade de carboidratos possível para o processo de fermentação alcoólica, porém essa biomassa precisa de um pré-tratamento para desorganizar a estrutura recalcitrante do material. Neste sentido, o principal objetivo deste projeto foi avaliar os métodos de pré-tratamentos alcalino, utilizando hidróxido de cálcio, e hidrotérmico, utilizando água, nos bagaços de cana-de-açúcar in natura (obtido diretamente da moenda) e explodido (submetido a explosão a vapor). Foram testados os tempos de 7, 30 e 60 minutos em ambos os tratamentos a uma temperatura de 120 °C em autoclave. Foram realizados planejamentos fatoriais completos a fim de analisar a influência do hidróxido de cálcio e do tempo no desempenho da hidrólise, quantificando a liberação de glicose e açúcares redutores totais (ART). Dessa maneira foram realizadas análises da composição química do bagaço pré-tratado a fim de avaliar uma possível correlação entre as modificações na estrutura do material e a eficiência da hidrólise. Os resultados mostraram que os melhores rendimentos foram obtidos com o bagaço in natura pré-tratado com hidróxido de cálcio em todos os tempos testados, a hidrólise enzimática desse material resultou em um rendimento mais alto, de 3,2 a 4,3 vezes, em comparação com a hidrólise no bagaço in natura sem pré-tratamento. Um novo planejamento foi realizado, delineamento composto central superfície resposta, para determinar as... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Due to the growing demand for alternative sources of fuel, ethanol production from lignocellulosic materials became an interesting option. This process allows the increase of ethanol production without the need of growth of the planted area of the cultivars used. For the production of cellulosic ethanol is necessary to fractionate the biomass to provide the largest possible amount of carbohydrates to ethanol fermentation process, but this biomass needs a pretreatment to disrupt the recalcitrant structure of the material. In this sense, the main objective of this project was to evaluate the methods of alkaline pretreatments, using calcium hydroxide, and hydrothermal,using water, in sugar cane bagasses in natura (obtained directly from the mill) and exploded (subjected to steam explosion). We tested different times (7, 30 and 60 minutes) in both treatments at a temperature of 120 °C in autoclave. Complete factorial designs were performed to examine the influence of calcium hydroxide and hydrolysis time performance by quantifying the release of glucose and total reducing sugars (TRS). Thus were analyzed the chemical composition of the pretreated bagasse to evaluate a possible correlation between changes in material structure and efficiency of hydrolysis. The results showed that the best yields were obtained with the in natura bagasse pretreated with calcium hydroxide at all times tested and the enzymatic hydrolysis increased from 3.2 to 4.3 fold compared to untreated in natura bagasse. A new schedule was conducted, a central composite design surface response, to determine the hydrolysis conditions which lead to maximal glucose release. In this step was done the hydrolysis of in natura bagasse subjected to alkaline pretreatment, with the addition of a nonionic surfactant (Tween 80). The best condition found in this optimization... (Complete abstract click electronic access below) / Mestre

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