The acid-catalyzed inversion of sucrose is often taken as an example of a first order reaction. It is, however, influenced by many factors such as temperature, type of acid used, concentration of sucrose, and the concentration of acid. What has received little attention so far is the influence of addition, in particular, other salts to the reacting solution. In this study, the influence of different salt solutions on the kinetics of sucrose inversion rate was studied at 29 °C by use of optical rotation measurements. The salts chosen for this study are readily soluble in sucrose solution and they provide an opportunity to study the interaction of electrolytes in aqueous solution of sucrose as well as their effects on the inversion of sucrose kinetics. The rates are found to be influenced by the concentration of the salts. No significant differences was measured when the salt were dissolved either in the sucrose or in the acid solutions. The influence of added salts to saccharide solutions was determined by evaluating the difference between the rotation of pure saccharides solutions and the rotation of pure saccharide solutions with salts. The changes in optical rotation were compared to the Hofmeister series. The saccharide-salt systems containing acidic salts (Na2HPO4 or NaH2PO4) were found to be dependent on the pH. Changing the molar ratio of sucrose and salt added also had an influence of the change in optical rotation. / Chemistry / M. Sc. (Chemistry)

Atualmente os combustíveis fósseis derivados do petróleo, tais como, gasolina, diesel e carvão são as principais fontes de energia. No entanto, essas fontes tendem ao esgotamento nos próximos 40 a 50 anos, além de sua utilização provocar problemas que vão desde a emissão de gases responsáveis pelo efeito estufa ao aumento nos preços desses combustíveis. Uma alternativa que vem sendo bastante utilizada é o etanol de primeira geração obtido principalmente do milho e da cana-de-açúcar. Apesar do etanol ser considerado uma energia limpa, por não emitir gases poluentes e auxiliar no sequestro de carbono, apresenta um problema relacionado à diminuição da oferta de alimentos e o consequente aumento de preços dos produtos que o utilizam como matéria-prima. Devido a esses fatores, vem crescendo os estudos por fontes de energias renováveis, como a obtenção do etanol de segunda geração, no qual, utiliza resíduos lignocelulósicos como matéria-prima. Nesse contexto, este trabalho objetivou avaliar a produção de etanol de segunda geração, tendo com matérias-primas os seguintes resíduos lignocelulósicos: bagaço de cana-de-açúcar, capim-elefante, serragens de Pinus sp. e Eucalyptus sp, pré-tratados com os líquidos iônicos 1-etil-3-metilimidazólio acetato e 1-butil-3-metilimidazólio acetato, separadamente. Após o pré-tratamento efetuou-se a hidrólise das biomassas lignocelulósicas com as enzimas produzidas pelo fungo Penicillium echinulatum, prosseguindo para a fermentação dos açúcares liberados na hidrólise, empregando as leveduras Saccharomyces cerevisiae e Schizosaccharomyces pombe Y 698, e a bactéria Geobacillus thermoglucosidasius. As maiores concentrações de açúcares redutores obtidas após as hidrólises enzimáticas foram 681,89 mg.g-1 para bagaço de cana-de-açúcar, 474,30 mg.g-1 para capim-elefante, 237,84 mg.g-1 para serragem de Eucalyptus sp. e 233,62 mg.g-1 para serragem de Pinus sp., sendo todos os pré-tratamentos com o líquido iônico 1-etil- 3-metilimidazólio acetato. O microrganismo que apresentou maior eficiência no consumo de açúcares redutores foi S. cerevisiae. Porém, o maior rendimento em etanol, cerca de 96 mg.g- 1, foi obtido para o bagaço de cana-de-açúcar pré-tratado com 1-butil-3-metilimidazólio acetato na fermentação com S. pombe. G. thermoglucosidasius apresentou potencial para consumo de xilose e glicose simultaneamente, porém a produção de etanol foi reduzida (21 mg.g-1 para bagaço de cana-de-açúcar). Este dados contribuem para ampliar os conhecimentos sobre os efeitos do pré-tratamento com líquidos iônicos na produção de etanol de segunda geração. / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2015-02-23T13:54:19Z No. of bitstreams: 1 Dissertacao Andria Tura.pdf: 2221504 bytes, checksum: 83ccbe502e3d5d9e76e0e69bee5d4e2a (MD5) / Made available in DSpace on 2015-02-23T13:54:19Z (GMT). No. of bitstreams: 1 Dissertacao Andria Tura.pdf: 2221504 bytes, checksum: 83ccbe502e3d5d9e76e0e69bee5d4e2a (MD5) / Fossil fuels, such as gasoline, diesel and coal, are the main sources of energy nowadays. In addition to generate problems, from the emission of greenhouse gases to the increase in fuel prices, these energy sources are likely to be depleted in the next 40 to 50 years. A widely used alternative to fossil fuels is first-generation ethanol, produced mainly from corn and sugarcane. Although ethanol is considered a clean source of energy because it does not emit polluting gases and helps in carbon sequestration, it is linked to a decrease in food supply and the consequent rise in food prices. Therefore, new studies on renewable energy sources, such as second-generation ethanol from feedstock and other lignocellulosic residues, are commonly found in the literature. In this context, this study aimed to evaluate the production of secondgeneration ethanol from the following lignocellulosic residues: sugarcane bagasse, elephant grass, Pinus sp. sawdust and Eucalyptus sp. sawdust, pretreated separately with the ionic liquids 1-ethyl-3-methylimidazolium acetate and 1-butyl-3-methylimidazolium acetate. Hydrolysis of lignocellulosic biomass with enzymes from Penicillium echinulatum was carried out after the pretreatment. Saccharomyces cerevisiae, Schizosaccharomyces pombe Y 698 and the bacterium Geobacillus thermoglucosidasius were used for the fermentation of sugars released during hydrolysis. The highest concentrations of reducing sugars obtained after enzymatic hydrolysis were 681.89 mg. g -1 for sugarcane bagasse, 474.30 mg.g -1 for elephant grass, 237.84 mg.g -1 for Eucalyptus sp. sawdust and 233.62 mg. g -1 for Pinus sp. sawdust, all pretreated with 1-ethyl-3- methylimidazolium acetate. S. cerevisiae was the microorganism with the highest efficiency in the consumption of reducing sugars. However, the highest ethanol yield (96 mg.g -1) was obtained for sugarcane bagasse pretreated with 1- butyl-3-methylimidazolium acetate and fermented by S. pombe. G. thermoglucosidasius showed potential for the simultaneous consumption of xylose and glucose, but ethanol production was low (21 mg.g -1 for sugarcane bagasse). These data contribute to expand the knowledge about the effects of ionic liquid pretreatments for the production of secondgeneration ethanol.

Atualmente os combustíveis fósseis derivados do petróleo, tais como, gasolina, diesel e carvão são as principais fontes de energia. No entanto, essas fontes tendem ao esgotamento nos próximos 40 a 50 anos, além de sua utilização provocar problemas que vão desde a emissão de gases responsáveis pelo efeito estufa ao aumento nos preços desses combustíveis. Uma alternativa que vem sendo bastante utilizada é o etanol de primeira geração obtido principalmente do milho e da cana-de-açúcar. Apesar do etanol ser considerado uma energia limpa, por não emitir gases poluentes e auxiliar no sequestro de carbono, apresenta um problema relacionado à diminuição da oferta de alimentos e o consequente aumento de preços dos produtos que o utilizam como matéria-prima. Devido a esses fatores, vem crescendo os estudos por fontes de energias renováveis, como a obtenção do etanol de segunda geração, no qual, utiliza resíduos lignocelulósicos como matéria-prima. Nesse contexto, este trabalho objetivou avaliar a produção de etanol de segunda geração, tendo com matérias-primas os seguintes resíduos lignocelulósicos: bagaço de cana-de-açúcar, capim-elefante, serragens de Pinus sp. e Eucalyptus sp, pré-tratados com os líquidos iônicos 1-etil-3-metilimidazólio acetato e 1-butil-3-metilimidazólio acetato, separadamente. Após o pré-tratamento efetuou-se a hidrólise das biomassas lignocelulósicas com as enzimas produzidas pelo fungo Penicillium echinulatum, prosseguindo para a fermentação dos açúcares liberados na hidrólise, empregando as leveduras Saccharomyces cerevisiae e Schizosaccharomyces pombe Y 698, e a bactéria Geobacillus thermoglucosidasius. As maiores concentrações de açúcares redutores obtidas após as hidrólises enzimáticas foram 681,89 mg.g-1 para bagaço de cana-de-açúcar, 474,30 mg.g-1 para capim-elefante, 237,84 mg.g-1 para serragem de Eucalyptus sp. e 233,62 mg.g-1 para serragem de Pinus sp., sendo todos os pré-tratamentos com o líquido iônico 1-etil- 3-metilimidazólio acetato. O microrganismo que apresentou maior eficiência no consumo de açúcares redutores foi S. cerevisiae. Porém, o maior rendimento em etanol, cerca de 96 mg.g- 1, foi obtido para o bagaço de cana-de-açúcar pré-tratado com 1-butil-3-metilimidazólio acetato na fermentação com S. pombe. G. thermoglucosidasius apresentou potencial para consumo de xilose e glicose simultaneamente, porém a produção de etanol foi reduzida (21 mg.g-1 para bagaço de cana-de-açúcar). Este dados contribuem para ampliar os conhecimentos sobre os efeitos do pré-tratamento com líquidos iônicos na produção de etanol de segunda geração. / Fossil fuels, such as gasoline, diesel and coal, are the main sources of energy nowadays. In addition to generate problems, from the emission of greenhouse gases to the increase in fuel prices, these energy sources are likely to be depleted in the next 40 to 50 years. A widely used alternative to fossil fuels is first-generation ethanol, produced mainly from corn and sugarcane. Although ethanol is considered a clean source of energy because it does not emit polluting gases and helps in carbon sequestration, it is linked to a decrease in food supply and the consequent rise in food prices. Therefore, new studies on renewable energy sources, such as second-generation ethanol from feedstock and other lignocellulosic residues, are commonly found in the literature. In this context, this study aimed to evaluate the production of secondgeneration ethanol from the following lignocellulosic residues: sugarcane bagasse, elephant grass, Pinus sp. sawdust and Eucalyptus sp. sawdust, pretreated separately with the ionic liquids 1-ethyl-3-methylimidazolium acetate and 1-butyl-3-methylimidazolium acetate. Hydrolysis of lignocellulosic biomass with enzymes from Penicillium echinulatum was carried out after the pretreatment. Saccharomyces cerevisiae, Schizosaccharomyces pombe Y 698 and the bacterium Geobacillus thermoglucosidasius were used for the fermentation of sugars released during hydrolysis. The highest concentrations of reducing sugars obtained after enzymatic hydrolysis were 681.89 mg. g -1 for sugarcane bagasse, 474.30 mg.g -1 for elephant grass, 237.84 mg.g -1 for Eucalyptus sp. sawdust and 233.62 mg. g -1 for Pinus sp. sawdust, all pretreated with 1-ethyl-3- methylimidazolium acetate. S. cerevisiae was the microorganism with the highest efficiency in the consumption of reducing sugars. However, the highest ethanol yield (96 mg.g -1) was obtained for sugarcane bagasse pretreated with 1- butyl-3-methylimidazolium acetate and fermented by S. pombe. G. thermoglucosidasius showed potential for the simultaneous consumption of xylose and glucose, but ethanol production was low (21 mg.g -1 for sugarcane bagasse). These data contribute to expand the knowledge about the effects of ionic liquid pretreatments for the production of secondgeneration ethanol.

Orientador: Elias Basile Tambourgi / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-20T02:06:50Z (GMT). No. of bitstreams: 1 Pinto_AmenoniaMariaFerreira_D.pdf: 8928817 bytes, checksum: adae0f7cc1ba62c41e7595bc4dd74788 (MD5) Previous issue date: 2012 / Resumo: A metodologia desenvolvida estabelece alternativas que possibilitam a quantificação do óleo estacionado no volume poroso dos reservatórios de petróleo. Foi admitido que, o conhecimento do coeficiente de partição do radônio entre o óleo e a água presentes no reservatório, viabilizará a determinação da Saturação Residual, levando-se em conta o aumento da quantidade de radônio na fase aquosa em relação à quantidade presente antes de ser iniciada a recuperação secundária, quando o óleo é expulso pela injeção de água. Foram executados testes, em escala de laboratório, em um corpo de prova composto por um meio poroso construído de forma a simular as características de um reservatório. O corpo de prova, elaborado a partir de uma rocha sedimentar de minério de urânio, foi acondicionado em um coreholder onde foram reproduzidas as etapas desde a formação até o esgotamento de um reservatório...Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: A method has been developed for the quantification of the amount of petroleum remaining within the porous volume of oil reservoirs using radon as a natural tracer. The Oil Saturation is estimated, taking into account the partition coefficient of radon between the organic and aqueous phases in the reservoir is known and the increase in the amount of radon in the aqueous phase, relatively to the amount initially present is accounted for. The methodology has been tested in experiments carried in reduced laboratory scale. A porous medium block prepared in such a way to approximately reproduce the reservoir characteristics has been used in the tests. The block was built out of a sandstone rock containing uranium ore whose radon emanation rate allows precise measurements in small volume samples placed in a coreholder. The steps leading from the formation to the depletion of the reservoir have been simulated...Note: The complete abstract is available with the full electronic document / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química

Many reactions carried out in the chemical industry are exothermic. The heat liberated by the reaction is often transferred to another medium such as steam by heat exchange. This heat can then be used elsewhere or be used to generate power via a steam cycle. In this work the focus is on another method of reaction heat recovery. When an exothermic reaction is conducted at elevated pressures, a turbine expander can be placed directly behind the reactor. The hot, high-pressure product gas from the reactor can then be expanded in the turbine. During the expansion process the physical energy of the product gas is converted to kinetic energy (or electricity if the turbine is connected to a generator). Three chemical processes were studied to determine the feasibility of turbine integration into the processes. They are ethylene oxide production, phthalic anhydride production and the hydrodealkylation of alkylaromatic compounds. The chosen processes differ in terms of reactor operation, reactant conversion as well as the presence or absence of recycle loops. Simulation models were developed for the mentioned processes with the process simulator Aspen Plus®. Results from the simulations show that, without the turbine, the processes require power from external sources. They can however operate independently from external power sources when a turbine is present. Excess power can be exported or used for electricity generation. It is therefore feasible• to incorporate turbine expansion units in all the processes considered. The operating conditions of some unit operations have to be changed to accommodate the turbine expander. With the additional product namely power, a re-evaluation of all the operating conditions and tradeoffs in the process is necessary. Further investigation into the impact of turbine integration on the optimal operating conditions of the process is therefore recommended. Traditional definitions used to evaluate the performance of a process generating or consuming power, were found to be inadequate for use in processes where power and chemicals are produced together. New performance parameters are required for the evaluation of processes where power and chemicals are produced simultaneously. An exergy analysis was performed for one of the cases. This analysis method provides insight as to where thermodynamic losses occur in a process. The exergy analysis was useful to quantify the losses occurring in an isenthalpic expansion valve, and the savings obtained by replacing such a valve with an expansion turbine. / Dissertation (MEng (Chemical Engineering))--University of Pretoria, 2006. / Chemical Engineering / unrestricted

<p> The study of free iron oxides in soils has for many years been an important area of research in the soil science. The development of many standard procedures over the years has free iron oxides. This study presents a systematic review of {a) the development of chemical processes and iron deposits in the podzolic group of soils, a major Canadian soil group in which free iron oxides deposits are found; {b) a review of the theory and experimental data behind some of the most widely accepted procedures of iron extraction; (c) a systematic review of four of the major methods of free iron extraction through experimental and statistical analysis employing soil samples from Thor Lake, N.W.T. The results of this study show that the most useful method for free iron oxide extraction is one that is independent of complexing variables such as pH, C.E.C., temperature and time.<p> / Thesis / Bachelor of Arts (BA)

No / The present study demonstrates the application of decision tree algorithms to the co-crystallization process. Fifty four (54) batches of carbamazepine–salicylic acid co-crystals embedded in poly(ethylene oxide) were manufactured via hot melt extrusion and characterized by powder X-ray diffraction, differnetial scanning calorimetry, and near-infrared spectroscopy. This dataset was then applied in WEKA, which is an open-sourced machine learning software to study the effect of processing temperature, screw speed, screw configuration, and poly(ethylene oxide) concentration on the percentage of co-crystal conversion. The decision trees obtained provided statistically meaningful and easy-to-interpret rules, demonstrating the potential to use the method to make rational decisions during the development of co-crystallization processes.

No description available.

This thesis discusses topics in the field of process engineering that have received much attention over the past twenty years: (1) conceptual process synthesis using heuristic shortcut methods and (2) process integration through heat-exchanger networks and energy-saving power and refrigeration systems. The shortcut methods for conceptual process synthesis presented in Chapter 2, utilize Residue Curve Maps in ternary diagrams and are illustrated with examples of processes for separating azeotropic mixtures. This chapter constitutes a comprehensive review of the most relevant literature of the last twenty years and was itself accepted for publication in Industrial and Engineering Chemistry Research in the Spring of 1994. We demonstrate the usefulness of RCMs as both a tool for teaching the complex techniques necessary for separating azeotropic mixtures and as a practical engineering aid for conceptual design of separation processes. We also give proper clarifications of some traditional misconceptions and contradicting recommendations in the literature. The introduction to and demonstration of process-integration topics in Chapters 3 through 6 are of value to both new and more experienced process engineers. The in-depth treatment of meaningful case studies in Chapters 4, 5 and 6 contain much useful information concerning complex heat-integration and process-retrofit problems. Chapter 4 discusses aspects of multiple-pinch heat-integration problems and ways to tackle them with two of the latest commercial process-integration softwares. Chapter 5 presents a review of and an extension to an Ethylene Plant Retrofit case study taken from the ADVENT Examples Manual (Aspen Technology, 1993), while Chapter 6 does the same for an Ethylene Plant Retrofit case study published earlier by the CACHE Corporation in 1985. / Ph. D.

Orientadores: Roger Josef Zemp, Valdir Apolinário de Freitas / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-21T11:39:16Z (GMT). No. of bitstreams: 1 Assis_CamillaAbbatide_M.pdf: 6993835 bytes, checksum: 7d87e3705f4d5bf8e95ea91406ca5a5b (MD5) Previous issue date: 2012 / Resumo: Um projeto de engenharia e realizado em cinco etapas consecutivas: planejamento do negocio, desenvolvimento do escopo, definição do projeto, execução (engenharia de detalhamento e construção) e, finalmente, partida e operacao. Muitas vezes percebe-se, na conclusão das etapas de desenvolvimento do escopo e de definição do projeto, apos intenso uso de tempo e de recursos, que o projeto não e mais viável economicamente, sendo abandonado ou reestudado. Decisões de projeto tomadas no inicio da concepção determinam configurações que afetarão permanentemente investimentos e custos operacionais. A engenharia de processos pode aliar conhecimentos técnicos a conceitos econômicos nas etapas iniciais, a fim de avaliar o impacto das decisões de configuração na viabilidade do projeto. Apesar de parecer natural, essa não e uma pratica comum na industria. Nesse contexto, o presente trabalho tem por objetivo realizar uma analise técnico-econômica de alternativas de configuração em estágios preliminares de um projeto. Para tal, será utilizado como estudo de caso o processo produtivo de acido nítrico a partir da combustão de amônia, em duas situações distintas: projeto de uma planta nova (síntese) e projeto de modificação de uma planta existente (revamp). A partir de analises simples, utilizando ferramentas que facilitam a avaliação da influencia de parâmetros no projeto, serão analisados os impactos das variações desses parâmetros em diferentes propostas de configurações / Abstract: An Engineering Project happens in 5 consecutive steps: business assessment, scope development, project definition, execution (detailed engineering and construction) and, finally, startup and operations. Many times, in the conclusion of the scope development and project definition steps, after intense use of time and resources, one realizes that the project is not economic feasible anymore, being abandoned or restudied. Project decisions taken in the early stages of design determine configurations that will affect permanently the investments and operational costs. The process engineering can combine technical knowledge to economic concepts at the early stages, to evaluate the impact of configurations decisions in the feasibility of the project. Although this may seem natural, it's not a common practice in the industry. In this context, this work aims to make a techno-economic analysis of configuration alternatives at the preliminary stages of a project. For this purpose, it will be used as a case study the production process of the nitric acid through the ammonia combustion, in two different situations: project of a new plant (synthesis) and project of modification in an existing plant (revamp). Through simple analysis, using tools that facilitate the evaluation of the parameters influence in the project, the impacts of the variations of these parameters in different alternatives of configuration will be evaluated / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestra em Engenharia Química