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Estudo termoanalitico e cinetico da combustão de oleo pesado / Thermoanalysis and reaction kinetics of heavy oil combustionPereira, Anderson do Nascimento 12 August 2018 (has links)
Orientador: Osvair Vidal Trevisan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica e Instituto de Geociencias / Made available in DSpace on 2018-08-12T07:44:05Z (GMT). No. of bitstreams: 1
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Previous issue date: 2008 / Resumo: Um dos maiores desafios nos estudos da Combustão In Situ é o desenvolvimento de um modelo cinético reacional de forma a representar a dinâmica das numerosas reações químicas que ocorrem em diferentes faixas de temperatura. O objetivo deste trabalho é desenvolver um estudo do comportamento oxidativo de um óleo pesado brasileiro e obter parâmetros cinéticos a partir dos dados experimentais gerados nas técnicas clássicas de análise térmica como TG, DTA e DSC. A análise térmica é sistematicamente desenvolvida em amostras de óleo e óleo com areia. Os dados experimentais nela obtidos são tratados para a realização de um estudo cinético global de acordo com diferentes modelos cinéticos não-isotérmicos convencionais e isoconversionais, gerados por método integral ou diferencial, todos baseados no modelo cinético de Arrhenius. Como resultado do estudo termoanalítico foram identificadas três regiões de oxidação: de baixa temperatura (OBT), de transição e de alta temperatura (OAT). Verificou-se uma maior intensidade na variação de massa e energia na faixa de OAT e um efeito de resistência de transferência de massa no final da OBT (efeito "skin"). Como resultado do estudo cinético, todos os modelos estudados forneceram valores de energia de ativação maiores na OAT do que na OBT. Observou-se que a presença de areia contribui para as reações OAT e dificulta o início da OAT por conta da acentuação do efeito "skin". / Abstract: One of the main challenges in studies on In Situ Combustion resides in developing a kinetic reaction model to represent the dynamics of the numerous chemical reactions that occur at different temperature ranges. The objective of the present research is to develop a study on the oxidation behavior of a crude Brazilian oil and obtain kinetic parameters from the experimental data generated through classical thermal analysis techniques, such as TG, DTA and DSC. Thermal analysis is systematically developed in samples of crude oil and oil mixed with sand, and the experimental data are treated in order to conduct a global kinetic study according to distinct conventional and iso-conversional non-isothermal models, developed using integral or differential methods, all based on Arrhenius's kinetic model. As a result of the thermo-analytical study addressed three oxidation regions have been identified: one at the low temperature (LTO) range, a transition zone and one at the high temperature (HTO) range. It has been verified that the highest variation of mass and energy generation occur at the HTO range. At the LTO range a mass transfer resistance (skin-effect) was evident. As a result of the kinetic study, all kinetic models studied provided higher activation energies in HTO than in LTO. It was noted that the presence of sand contributed to OBT and delayed HTO mode as a result of an increase in skineffect. / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo
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Flexographic deinking with electric field technology by destabilization and flotationShemi, Akpojotor 02 July 2008 (has links)
Every year, millions of tons of paper are diverted from landfills and recycled. Newspaper constitutes a large portion of total paper recycled, providing a cheap source of raw material for the paper industry and helping sustainable forestry. The recycling of newsprint paper involves the separation of ink from the newsprint, which is done either by flotation or washing. Conventional flotation processes for separating ink are not adequate for newsprint printed using flexography printing technique and with water-based ink. The removal of these flexographic water-based inks by washing is a better alternative. However, one drawback of washing is that it has lower yield. In addition, the subsequent wash filtrate is difficult and costly to decontaminate. The overall goal is to develop a combination of processes that can remove ink from a feedstock that contains up to 100% flexographic ink newsprint; in the context of process variables with known effects.
In the present work the objectives are to (1) demonstrate that incorporating an electric field into a conventional deinking process improves deinking efficiency, (2) propose a mechanism of how incorporating an electric field helps to improve deinking efficiency, (3) demonstrate that an electric field can decontaminate water containing flexographic inks and identify the mechanism behind electric field clarification of water, and (4) demonstrate that by incorporating electric fields into both the flotation deinking stage and water decontamination, the target deinking efficiency can be achieved.
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