Thesis (PhD(Agricultural Economics, Extension and Rural Development))--University of Pretoria, 2005. / Abstract in English. Includes bibliographical references.

京都大学 / 新制・課程博士 / 博士(エネルギー科学) / 甲第23394号 / エネ博第421号 / 新制||エネ||80(附属図書館) / 京都大学大学院エネルギー科学研究科エネルギー社会・環境科学専攻 / (主査)教授 河本 晴雄, 教授 髙野 俊幸, 准教授 奥村 英之 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

Thesis. 1978. Sc.D.--Massachusetts Institute of Technology. Dept. of Chemical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND SCIENCE. / Bibliography: leaves 382-396. / by Eric M. Suuberg. / Sc.D.

Coal is one of the world's largest remaining mineral resources. The supply of this rich source of fuel and chemicals is sufficient to serve the world for several thousand years. Coal is used directly and is also heat treated at high and low temperatures to produce fuel and by-products. Of the several methods of treatment that can be used, low-temperature carbonization is one of the most promising. Nearly all of the coke and coal chemicals produced today come from the production of high temperature coke. However, there are many lower rank coals not suited for metallurgical purposes that will produce an excellent char and high yields of by-products. One of the disadvantages of many lower rank coals is their tendency to swell and become plastic when heated to carbonization temperatures, and this property has to a great extent made the operation of the retorts difficult. In an effort to reduce or circumvent this undesirable property, several methods of pretreating the raw coal have been tried including preoxidation, dilution with non-coking coal, preheating, and weathering. The type and severity of the pretreatments vary in their effects on the coking properties of different coals. The purpose of this investigation was to study the effect of preoxidation on the coking properties and the quantities and composition of the byproducts and char obtained from the low-temperature carbonization of Penn-Lee coal. / Master of Science

Milk and even cream were carbonated during the following processes: separation, pasteurization and during storage. Solid and gaseous carbon dioxide were used in these treatments. Untreated milk and cream were processed and stored as checks. Various methods of carbonation were employed. The different tests and determinations that were made on the samples were as follows: acidity percentage; pressure developed by subliming solid carbon dioxide; influence of solid carbon dioxide upon temperature; amount of gases absorbed by the fluids when different methods of carbonation were used; effects of carbon dioxide upon the number of bacteria; and the influence of carbon dioxide on the flavor. It was found that the quality of the dairy products studied was improved when those products were treated with carbon dioxide. The degree of improvement was in direct proportion to the amount of carbon dioxide absorbed by the product. Carbonation imparts and intense off flavor to milk. The intensity of this off flavor decreases as the storage period of the milk lengthens. / Master of Science

La croissance démographique mondiale, associée à une augmentation générale du niveau de vie, se traduit par l'explosion des besoins en matières premières et énergie. Afin de relever ce défi, une attention accrue est accordée aux énergies et ressources naturelles renouvelables. Parmi elles, la biomasse est particulièrement prometteuse. Elle présente des avantages certains (abondance, répartition homogène) mais aussi plusieurs inconvénients (faible densité énergétique, humidité élevée,…). Pour surmonter ces difficultés, la torréfaction est la méthode la plus connue, mais elle induit une augmentation des taux de cendres et une perte de matière. La carbonisation hydrothermale (HTC) est une alternative possible. L'objet de cette thèse est l'étude de la HTC comme moyen de bonifier la biomasse lignocellulosique. Trois axes principaux ont été considérés: augmentation de la densité énergétique, récupération de molécules, et minéraux d'intérêt. L'étude porte d'abord sur la HTC de systèmes moléculaires représentatifs de ceux présents dans le bois. Le hêtre a été étudié comme biomasse modèle, permettant de déterminer des conditions expérimentales optimales, appliquées ensuite à diverses biomasses. Enfin d'autres méthodes d'activation ont été testées telles que les micro-ondes et les fluides supercritiques. Les hydrochars obtenus après HTC présentent une diminution concomitante des ratios atomiques H/C et O/C. La phase liquide contient différentes molécules d'intérêt (furfural,…). Enfin, les teneurs en cendres diminuent après HTC du fait d'une lixiviation partielle de certains éléments (alcalins et alcalino-terreux). En conclusion, la HTC semble être une alternative intéressante à la torréfaction ; elle permet la production d'hydrochars avec des teneurs élémentaires adaptées à une utilisation en gazéification et la récupération de molécules et minéraux. L'intérêt et la faisabilité technique ont été démontrés en particulier sur des biomasses humides (plantes agricoles) ou polluées (broyats de déchetterie). / Population growth, coupled with a general increase in standard of living, result in a booming demand for raw material and energy. To face this challenge, an increased attention is paid to the use of renewable energies and natural resources. Among them, biomass is especially promising. Its advantages (abundance, distribution all over the Earth) are balanced by several drawbacks (low energy density, high moisture content,…). To overcome these problems, torrefaction is the most traditional way, but it has some inconveniences (increased ash content, loss of material). Hydrothermal carbonisation (HTC) is a possible alternative. The purpose of this thesis is the study of HTC a means to beneficiate the lignocellulosic biomass. Three main aims were identified: increase of the energy density, recover molecules and minerals of interest. The study initially focused on HTC of molecular model systems present in wood. Beech wood was also studied, as a model biomass. This study allowed determining optimal experimental conditions for treatment of further biomasses. Finally, other activation methods have been tested, such as microwaves, and supercritical fluids. Hydrochars obtained after HTC feature a concomitant decrease of the atomic H/C and O/C ratios. Liquid phase contains different molecules of interest (furfural,…). Finally, ash content decreases after HTC owing to a partial leaching of some elements (alkali and alkaline earth metals). In conclusion, HTC seems to be an interesting alternative to torrefaction as it allows for the production of hydrochars suitable for gasification, and the recovery of molecules and minerals of interest. The interest and technical feasibility have been demonstrated in particular for biomasses with high moisture (agricultural crops) or with high pollutant contents (grounds of waste disposal).

Submitted by Eunice Novais (enovais@uepg.br) on 2018-07-24T18:08:19Z No. of bitstreams: 2 license_rdf: 1037 bytes, checksum: 996f8b5afe3136b76594f43bfda24c5e (MD5) RAFAELA FABER DE CAMPOS.pdf: 3462807 bytes, checksum: 7d5b40498bba51c7d7e5694876f08985 (MD5) / Made available in DSpace on 2018-07-24T18:08:19Z (GMT). No. of bitstreams: 2 license_rdf: 1037 bytes, checksum: 996f8b5afe3136b76594f43bfda24c5e (MD5) RAFAELA FABER DE CAMPOS.pdf: 3462807 bytes, checksum: 7d5b40498bba51c7d7e5694876f08985 (MD5) Previous issue date: 2017-02-02 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / A biomassa sempre foi uma fonte de energia utilizada pelo homem, antes mesmo da utilização de petróleo e gás natural. Porém nos últimos anos com a necessidade de mitigação das mudanças climáticas e, com o aumento da demanda mundial por energias alternativas, além da energia solar, eólica e hidrelétrica, uma delas é a utilização de biomassa vegetal. Este tipo de energia representa 10% do fornecimento mundial. A maior parte desta biomassa ainda é proveniente de florestas nativas, chamada de “biomassa tradicional”, causando impacto, de certa forma, ao meio ambiente. Entretanto, a utilização do bambu como biomassa para geração de energia torna-se uma alternativa sustentável e interessante, pois dentre suas várias características, destaca-se sua facilidade de propagação. Desta forma, o objetivo, do presente trabalho foi avaliar o potencial energético de quatro espécies de bambu, in natura e em forma de carvão. As espécies selecionadas foram Phyllostachys aurea A. C. Rivière (bambu dourado), Chusquea gracilis McClure & Smith (criciúma), Chusquea mimosa McClure & Smith (caratuva) e Merostachys multiramea Hackel (taquara lixa), do município de São Mateus do Sul, PR. As espécies de bambu foram avaliadas quanto ao teor de umidade, massa específica, composição química imediata, rendimento gravimétrico em carvão e ao poder calorífico superior. A espécie Phyllostachys aurea in natura apresentou poder calorífico superior de 18,91 MJ kg-1 e teor de cinzas de 0,49%. O carvão, 25,05 MJ kg-1 e 1,24%, respectivamente. Os valores de teor de cinzas para as biomassas in natura das espécies Merostachys multiramea, Chusquea gracilis e Chusquea mimosa, foram de 3,95%, 2,76% e 4,90% e, carbonizadas ficaram com valor de 5,43%, 6,43% e 7,93%, respectivamente. O poder calorifico superior da espécie C. mimosa foi de 25,55 MJ kg-1, mas devido a grande geração de cinzas após queima e massa específica de 0,20 g cm-3 in natura e de 0,10 g cm-3 do carvão, talvez sejam características mais interessantes para utilização como carvão ativado. A massa específica do Phyllostachys aurea foi de 0,63 g cm-3 in natura e 0,41 g cm-3, carbonizada. O alto teor de cinzas das espécies pode estar relacionado aos teores de constituintes minerais presentes no vegetal. Apesar disso, todas as espécies apresentaram características favoráveis para a utilização com fins energéticos, mas a espécie Phyllostachys aurea foi a que se apresentou mais semelhante às características apresentadas pela madeira de eucalipto, comumente utilizada para este fim. / Biomass has always been an energy source utilized by humans, even before, the use of oil and natural gas. However, in the last couple of years, the need to mitigate climate change and the global demand increase for alternative fuel, besides Solar, Eolic and Hydro energies, one of them is the use of vegetal biomass. Such energy represents 10% of the world supply. Most of this biomass still comes from native forests and it’s called “traditional biomass”, causing great impact, in some way, to the environment. On the other hand, the use of bamboo as biomass for the generation of energy becomes a sustainable and interesting alternative, because among its characteristics, it’s spread ease is highlighted. In this sense, the goal of the present research, is to analyze the energy potential of four bamboo species, in natura and in charcoal form. The selected species were Phyllostachys aurea A.C. Rivière (golden bamboo), Chusquea gracilis McClure & Smith (criciúma), Chusquea mimosa McClure & Smith (caratuva) and Merostachys multiramea Hackel (sandpaper taquara), from the city of São Mateus do Sul, PR. The bamboo species were evaluated according to their moisture rate, specific mass, immediate chemical composition, coal gravimetric yield and superior calorific value. The Phyllostachys aurea species in natura presented superior calorific value of 18.91 MJ kg -1 and ash rate of 0.49%. The coal presented 25.05 MJ kg -1 and 1.24%, respectively. The ash rate value for Merostachys multiramea, Chusquea gracilis e Chusquea mimosa were 3.95%, 2.76% e 4.90%, whereas carbonized they were 5.43%, 6.43% e 7.93%, respectivey. The C. mimosa species’ superior calorific value was 25.55 MJ kg-1 but due to great ash generation after the burn and specific mass of 0.20 g cm-3 in natura and 0.10 g cm-3 in coal, may be better characteristics for activated charcoal use. Phyllostachys aurea’s specific mass was 0.63 g cm-3 in natura and 0.41 g cm-3 carbonized. The species’ high ash rate may be related to the mineral constituent rate present in the plant. In spite of that, all species presented favorable characteristics to use for energetic purposes, but the Phyllostachys aurea species was the one which presented itself more similar to those characteristics presented by eucapiltus wood, commonly used for this purpose.

Os resíduos orgânicos alimentares são um tipo de resíduo de difícil aproveitamento. Milhões de toneladas de lixo orgânico são descartados todos os anos, sobretudo os de origem alimentar, sendo que boa parte não é reaproveitada. Tradicionalmente, quando reaproveitados, esses resíduos são destinados à compostagem. No entanto, para que esse processo seja bemsucedido, é necessário que os resíduos sejam separados corretamente a fim de que a qualidade do produto final seja aceitável para o uso como fertilizante. Uma alternativa proposta de utilização dos resíduos alimentares consiste na produção de material carbonáceo obtido pela carbonização ou torrefação destes. Avaliam-se as propriedades e as características qualitativas e quantitativas desses materiais carbonáceos e seus derivados, como a composição, a resistência mecânica e a microestrutura. Tenciona-se, desse modo, contribuir para o conhecimento das possíveis aplicações desses carvões, materiais carbonosos e derivados em diversas áreas da indústria, inclusive na siderúrgica. / Millions of tons of organic waste are discarded every year, especially from food sources, and most of it is not reused. Traditionally, when reused, this kind of waste is destined for composting. However, for that procedure to be successful it is necessary that the waste is properly separated so that the quality of the final product is acceptable for fertilizer. An alternative reuse of food waste constitutes obtaining carbonaceous material by carbonization or torrefaction of this material. This work studies the charcoalmaking that uses these kind of residues, the characteristics of charcoals obtained, and the possible applications for these carbonaceous materials. The properties and the qualitative and quantitative characteristics of this object of study, such as its composition, its mechanical resistance and its microstructure, are evaluated. It is intended to contribute to the knowledge of the possible applications of these charcoals in several areas of industry, including in the steel industry.

The prolonged challenges and dire consequences of poor sanitation, especially in developing economies, call for the exploration of new sustainable technologies. These need to be: capable of effectively treating human faecal wastes without any health or environmental impacts; scalable to address rapid increases in population and urbanization; capable of meeting environmental regulations and standards for faecal management; and competitive with existing strategies. Further and importantly, despite its noxiousness and pathogenic load, the chemical composition of human biowaste (HBW) indicates that it may be considered to be a potentially valuable, nutrient-rich renewable resource, rather than a problematic waste product. This doctoral study therefore investigated microwave hydrothermal carbonization (M-HTC) as a sanitation technology for processing HBW - to convert it into a safe, pathogen-free material, while also recovering inherent value and providing an economic base to sustain the technology. To this end, the products of M-HTC treatment of sewage sludge, human faecal sludge, synthetic faecal simulant and human faeces were characterized with a suite of techniques and tests to demonstrate pathogenic deactivation, and the intrinsic value of the resultant solid char and liquor.

Thesis (Ph. D.(Chemical Engineering))--University of Pretoria, 2003. / Title from opening screen (viewed June 14, 2004). Includes bibliographical references.