Orientador: Martín Aznar, Rubens Maciel Filho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-17T00:28:23Z (GMT). No. of bitstreams: 1 AlvarezAlvarez_VictorHugo_D.pdf: 123512819 bytes, checksum: ab445a730c3a4943154e0b3ab2a37b10 (MD5) Previous issue date: 2018-08-16T21:28:09Z / Resumo: Os líquidos iônicos são uma interessante alternativa para aperfeiçoar processos com objetivos econômicos e ecológicos. Esta pesquisa tem como objetivo estudar propriedades físico-químicas de líquidos iônicos, próticos e apróticos, puros ou em misturas binárias com ésteres e aldeídos, tais como densidade, velocidade do som, viscosidade aparente, índice de refração e temperatura de decomposição térmica. Além disso, é estudado o comportamento termodinâmico de algumas aplicações dos líquidos iônicos, como equilíbrio líquido-vapor, absorção de gases e equilíbrio líquido-líquido. Inicialmente, foram sintetizados onze líquidos iônicos próticos usando moléculas de hidroxiaminas no cátion e moléculas de ácido orgânico com cadeias alquílicas de diferentes tamanhos no ânion. As propriedades físico-químicas dos líquidos iônicos, no estado puro e em misturas, indicam a formação de agregados nos líquidos iônicos próticos com mais de dois carbonos no ânion, e que o líquido iônico prótico contendo o ânion formiato é instável, formando um éster com o passar do tempo. Nos líquidos iônicos puros, a densidade diminui com o crescer da temperatura ou a cadeia alquílica do ânion; além disso, a viscosidade diminui com o crescer da temperatura, mas aumenta com o crescer da cadeia alquílica do ânion. Nos resultados das misturas binárias de líquidos iônicos com aldeídos ou ésteres, mostra-se que os líquidos iônicos baseados no cátion amônio são parcialmente insolúveis em aldeídos, ocorrendo o contrário para o líquido iônico baseado no cátion imidazólio, embora sejam insolúveis em ésteres. No equilíbrio líquido-vapor a baixas pressões de sistemas binários, observa-se o aumento da temperatura de ebulição do aldeído ou éster influenciado pela concentração do líquido iônico, e a mudança do ponto azeotrópico na mistura etanol-água. No equilíbrio líquido-vapor a altas pressões, o CO2 é mais absorvido nos líquidos iônicos próticos do que nos líquidos iônicos apróticos, especialmente naqueles que contêm o ânion acetato, mostrando quimisorção nesse grupo funcional. No equilíbrio líquido-líquido do sistema ternário líquido iônico + dibenzotiofeno + n-dodecano, observa-se que os líquidos iônicos baseados no cátion amônio conseguem extrair dibenzotiofeno do n-dodecano, tanto quanto um líquido iônico baseado no cátion imidazólio de estrutura mais complexa. Nos estudos de absorção desde uma corrente de CO2 em dois líquidos iônicos próticos a pressão ambiente, a temperatura e o fluxo de gás foram as variáveis limitantes da absorção. Os dados do equilíbrio líquido-vapor e densidade das misturas binárias foram correlacionados através da equação de estado de Peng-Robinson acoplada com a regra de mistura Wong-Sandler/GE. Para o cálculo de GE, foram implementados os modelos termodinâmicos de NRTL, UNIQUAC e COSMO-SAC. Para o equilíbrio líquido-vapor, os desvios na predição foram menores que 2,5% e na correlação menores que 1,5%. Para a densidade da solução, os desvios na predição foram menores que 2,7%. Assim, os líquidos iônicos e as aplicações estudadas demonstram que estes novos compostos podem ser usados para produzir novos processos e os modelos termodinâmicos disponíveis na literatura podem representar esses processos com precisão / Abstract: The ionic liquids are an interesting alternative to improve processes with ecological and economic goals. This research aims to study the physicochemical properties of aprotic and aprotic ionic liquids, pure or in binary mixtures with esters and aldehydes, such as density, sound velocity, viscosity, refractive index and thermal decomposition temperature. Furthermore, it is analized the thermodynamic behavior of some applications of ionic liquids as vapor-liquid equilibrium, gas absorption, and liquid-liquid equilibrium. Initially, eleven protic ionic liquids were synthesized using hydroxylethylamine molecules in the cation and organic acid molecules with alkyl chains of different sizes in the anion. The physicochemical properties in pure and in mixtures of ionic liquids indicate the formation of agregates with more than two carbons in the anion. The protic ionic liquid containing the formate anion is unstable, forming an ester over time. In pure ionic liquids, the density decreases with increasing temperature or alkyl chain of the anion, the viscosity decreases with increasing temperature, but increases with increasing alkyl chain anion. In the results of binary mixtures of ionic liquids with aldehydes and esters, it is shown that ionic liquids based on ammonium cation are partly insoluble in aldehydes ans soluble in esteres, but for the ionic liquid based on imidazolium was the opposite. In the vapor-liquid equilibrium at low pressures of binary systems, there is a increase of the boiling point of the aldehyde or ester influenced by the concentration of ionic liquid. It changes the azeotropic point of ethanol-water mixture. In the vapor and liquid at high pressures, more CO2 is absorbed in the protic ionic liquids than in aprotic ionic liquids. This is especially shown in those containing acetate anion, indicating quimisorption with this functional group. In liquid-liquid equilibrium of ternary system ionic liquid + dibenzothiophene + n-dodecane, it is observed that the ionic liquids based on ammonium cation can be extracted dibenzothiophene from n-dodecane. Both as an ionic liquid based on imidazolium cation of more complex structure. In studies of absorption from a CO2 flow in two protic ionic liquids at ambient pressure, the variables limiting the absorption were the temperature and flow rate. Data from the vapor-liquid equilibrium and density of binary mixtures were correlated using the equation of state of Peng-Robinson with the mixing rule of Wong-Sandler/GE. For the calculation of GE, it was implemented thermodynamic models as NRTL, UNIQUAC and COSMO-SAC. For the vapor-liquid equilibrium, the deviations in the prediction and correlation were lower than 2.5% and 1.5%, respectively. For the mixture density, the deviations in the prediction were lower than 2.7%. Therefore, the ionic liquids an the applications studied demonstrate that these new compounds are reliable to yield new processes and the current thermodynamic models can represent these processes with accuracy / Doutorado / Desenvolvimento de Processos Químicos / Doutor em Engenharia Química

Orientador: Liliane Lona / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-09T09:29:23Z (GMT). No. of bitstreams: 1 Pereira_YuriGuerrieri_M.pdf: 1827964 bytes, checksum: 8c6635139bee2d39bd01aba8b6a2c335 (MD5) Previous issue date: 2007 / Resumo: Os sistemas poliméricos, sejam eles reacionais ou não-reacionais, são em geral bastante complexos, devido à própria estrutura das cadeias das suas moléculas e pela existência de diversas interações entre elas. No que se refere à termodinâmica de sistemas poliméricos, este é um aspecto fundamental em muitos processos de polimerização, uma vez que têm impacto direto nas características dos materiais formados. Neste sentido, este trabalho tem como objetivo investigar o comportamento de sistemas poliméricos em duas plantas industriais de produção de polietileno, denominadas aqui como Planta PEBD, onde é produzido polietileno de baixa densidade (PEBD), e Planta PEL, onde são produzidos polietileno linear de baixa densidade (PELBD) e polietileno alta densidade (PEAD). Na Planta PEBD foi estudado o equilíbrio líquido-líquido a alta pressão, presente no reator, e o equilíbrio líquido-vapor presente no separador de baixa pressão (flash). Para este estudo foram utilizadas 8 resinas produzidas comercialmente. Na Planta PEL foi estudado o equilíbrio líquido-vapor presente no separador de pressão intermediaria (flash). Para este estudo foram utilizadas 25 resinas produzidas comercialmente. De um modo geral foram feitas as modelagens de sistemas binários e multicomponentes constituídos por: etileno, etano, propeno, propano, 1-buteno, cicloexano, 1-octeno e polímero. Os dados experimentais utilizados foram gerados a partir de medições disponíveis e balanços de massa e energia em ambas as plantas industriais. Para a modelagem dos equilíbrios de fases investigados neste trabalho foi utilizada a equação de estado PC-SAFT (Perturbed-Chain Statistical Associating Fluid Theory, Teoria Estatística de Fluidos Associativos com Cadeia Perturbada), que tem apresentado desempenho superior ao das suas antecessoras. Após a implementação computacional, o modelo foi validado para ambas as plantas industriais. Os resultados mostram que, para alguns sistemas, os parâmetros binários encontrados na literatura são suficientes para uma boa modelagem; para outros, quando os parâmetros de interação binária são ajustados na equação, o modelo apresenta-se capaz de representar melhor os dados experimentais / Abstract: Polymeric systems, with or without chemical reactions, are in general much complex due to molecules structure and due to the existence of many interactions between them. Thermodynamics of polymeric systems, and more specifically phase equilibria, is a fundamental aspect in many polymerization processes, since they influence directly in the characteristics of the material produced. In this way, the objective of this work is to investigate the behavior of polymeric systems in two industrial plants of polyethylene production, called here as PEBD Plant, where low density polyethylene (LDPE) is produced, and PEL Plant, where linear low density polyethylene (LLDPE) and high density polyethylene (HDPE) are produced. In PEBD Plant liquid-liquid equilibria in the reactor unit and vapor-liquid equilibria in the low pressure separator (flash) were studied. For this study 8 resins produced commercially were used. In PEL Plant vapor-liquid equilibria present in the intermediate pressure separator (flash) was studied. For this study 25 resins produced commercially were used. In a general way binary and multicomponent systems were modeled, with the following components: ethylene, ethane, propylene, propane, 1butene, ciclohexane, 1-octene and polymer. The experimental data used has been generated through a few measurements at disposal and though mass and energy balance calculations in both industrial plants. In modeling phases equilibria investigated in this work, PC-SAFT (Perturbed-Chain Statistical Associating Fluid Theory) equation of state was used, since it has presented superior performance when compared with its predecessors. After the computational implementation, the model was validated for both industrial plants. The results show that, for some systems, the binary parameters found in literature had been good enough for modeling purposes. In others systems, when binary interaction parameters were adjusted in the equation, the model had presented a better capability in representing the experimental data / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

Garnets are major silicates from the upper mantle to the transition zone. Elastic properties of garnets are essential to interpret the variation of seismic velocities at different depths and construct a model of the Earth’s composition. Due to the chemical flexibility at octahedron sites of the crystal structures, garnets usually exist with multiple components and have many composition variations. Pyrope is an important member in the garnet group. Fe2+-Mg2+ substitution in pyrope is one of the common solid solutions. We have synthesized and measured three synthetic solid solutions samples (Py83Alm17, Py54Alm46 and Py30Alm70). Equations of state yielded their isothermal bulk moduli K0 to be 172(4)GPa, 174(2)GPa, and 183(2)GPa, respectively, which confirmed that almandine content (Fe2+ substitution) increased the bulk modulus of the garnet. A relation between the bulk modulus and the almandine mole fraction (n) was derived to be K0 = 170 + 15 n, showing it is a nearly ideal mixing model. Another factor that also significantly influences the elasticity of pyrope is water. Water is transported to the deep Earth by subduction slabs and mainly exists in nominally anhydrous minerals (NAM) as hydroxyl (OH-). Its content in minerals varies as depth increases. We therefore investigated pressure influence on water solubility in pyrope. A suite of pyrope single crystals was synthesized in a water-saturated environment at 6, 7, 9 and 12GPa and water was characterized by FTIR. IR spectra showed a typical peak at 3630 cm-1. At 9 and 12GPa, new peaks at 3572 cm-1 and 3504 cm-1 appeared and indicated that a new substitution mechanism, other than hydrogarnet substitution SiO4=(OH)4, was adopted in the pyrope crystal structure. Water solubility in pyrope reached 0.2wt% at 7GPa. From 4-7GPa, water solubility increased. At 9GPa, water content dropped to 0.07wt% and increased to 0.3wt% at 12GPa, where a cubic to tetragonal phase transition was observed. Water showed a weakening effect on the bulk moduli of hydrous pyrope. Their bulk moduli were 166GPa, 173GPa and 161GPa with water contents of 0.07wt%, 0.1wt% and 0.2wt%, respectively. An approximate linear relationship was proposed about the bulk modulus as a function of water content.

Modern mining explosives employ solutions of ammonium nitrate, where the solution is the oxidising component of a fuel/oxidiser mixture. This thesis is primarily concerned with the shock response of water and of aqueous solutions of ammonium nitrate. Of particular interest are the temperatures induced through shock compression. An experimental facility, using a single stage gas gun in the 'plate impact' configuration, is described, along with associated experimental diagnostics. Measurements of, and improvements to, the tilt at impact are reported. The problem of shock temperature is discussed, including a brief review of the relevant literature. It is demonstrated that direct measurement of shock temperature is a complex issue that is not yet fully understood, whereas determination of temperature from an equation of state is an established technique. In a series of experiments, plate impact techniques were utilised to determine the Hugoniot and, through shock/reload experiments, the equation of state of water and aqueous solutions of ammonium nitrate. In-situ manganin gauges were used to measure stresses in the liquids and, from the arrival times of the shock wave, determine the shock velocity. Linear shock velocity-particle velocity Hugoniots for the liquids were determined, up to particle velocities of 1km/s, with uncertainties on the intercept and slope of these Hugoniots of 5%. A Mie-Grûneisen equation of state was used to describe the shock/reload experiments. Approximate calculations of shock temperature are reported. Increasing ammonium nitrate concentrations resulted in greater calculated temperatures. It was demonstrated that the liquids investigated in this thesis show a temperature dependence of the Grûneisen parameter, ?, which cannot be accommodated in the model. The present work is believed to be the first demonstration of this effect in shock compressed liquids. The data presented provide constraints on future theoretical development of equations of state.

No description available.

The quasiparticle model, based on quark and gluon degrees of freedom, has been developed for the description of the thermodynamics of a hot plasma of strongly interacting matter which is of enormous relevance in astrophysics, cosmology and for relativistic heavy-ion collisions as well. In the present work, this phenomenological model is extended into the realm of imaginary chemical potential and towards including, in general, different and independent quark flavour chemical potentials. In this way, nonzero net baryon-density effects in the equation of state are self-consistently attainable. Furthermore, a chain of approximations based on formal mathematical manipulations is presented which outlines the connection of the quasiparticle model with the underlying gauge field theory of strong interactions, QCD, putting the model on firmer ground. A comparison of quasiparticle model results with available lattice QCD data for, e. g., basic bulk thermodynamic quantities and various susceptibilities such as diagonal and off-diagonal susceptibilities, which provide a rich and sensitive testing ground, is found to be successful. Furthermore, different thermodynamic quantities and the phase diagram for imaginary chemical potential are faithfully described. Thus, the applicability of the model to extrapolate the equation of state known from lattice QCD at zero baryon density to nonzero baryon densities is shown. In addition, the ability of the model to extrapolate results to the chiral limit and to asymptotically large temperatures is illustrated by confrontation with available first-principle lattice QCD results. These extrapolations demonstrate the predictive power of the model. Basing on these successful comparisons supporting the idea that the hot deconfined phase can be described in a consistent picture by dressed quark and gluon degrees of freedom, a reliable QCD equation of state is constructed and baryon-density effects are examined, also along isentropic evolutionary paths. Scaling properties of the equation of state with fundamental QCD parameters such as the number of active quark flavour degrees of freedom, the entering quark mass parameters or the numerical value of the deconfinement transition temperature are discussed, and the robustness of the equation of state in the regions of small and large energy densities is shown. Uncertainties arising in the transition region are taken into account by constructing a family of equations of state whose members differ from each other in the specific interpolation prescription between large energy density region and a realistic hadron resonance gas equation of state at low energy densities. The obtained family of equations of state is applied in hydrodynamic simulations, and the implications of variations in the transition region are discussed by considering transverse momentum spectra and differential elliptic flow of directly emitted hadrons, in particular of strange baryons, for both, RHIC top energy and LHC conditions. Finally, with regard to FAIR physics, implications of the possible presence of a QCD critical point on the equation of state are outlined both, in an exemplary toy model and for an extended quasiparticle model.

No description available.

In this research, we study how a finite-temperature nuclear equation of state suitable for astrophysical simulations impacts the oscillation modes of neutron stars. We chose the Shen equation of state (EOS) because it accurately describes both stable and unstable nuclei as well as nuclear incompressibilities. I modified the existing MHD code at BYU, the HAD code, to call a lookup table for the Shen EOS for use at run time, and added a Newton-Raphson method algorithm to convert conserved variables to primitive variables. The algorithm was tested and verified by evolving a stable neutron star for several dynamical times and evolving the same star at different resolutions. The normal mode frequency of the neutron star with the Shen EOS was measured and compared to those for neutron stars with an ideal gas EOS found by Font et. al. We found that the fundamental mode of the neutron star using the Shen EOS was slightly larger than that of the ideal gas EOS. This difference is due to the Shen EOS producing stars that are stiffer, increasing the sound speed.

This thesis is concerned with the numerical simulation of mixtures of chemically reacting fluids at high pressures. Mixture rules are established, accommodating components that do not follow the thermally perfect Equation of State (EoS), and including formulas for the fugacities. Particular attention has been given to the species EoS originally developed by Hirschfelder, Buehler, McGee and Sutton. The Law of Mass Action that governs chemical equilibrium of mixtures of fluids is presented. The common assumption of neglecting fugacities contributions when calculating the equilibrium composition is assessed by comparing complete thermochemical predictions with those obtained by reduced models. For air mixtures at high pressures and moderate temperatures, species thermally imperfect EoS effects are significant. However, the contribution of fugacities to the Law of Mass Action is found to be small, at least for mixtures of super-critical dissociating gases. Similar conclusions apply to combustion mixtures (involving hydrogen and oxygen).

Feldspars are one of the archetypical families of framework silicates. They not only comprise around 60% volumetrically of the Earth's crust, but are among some of the most structurally complicated minerals. Investigation into the structural behavior of various intermediate plagioclases at pressure has been undertaken with the intent of categorizing the elastic behavior with pressure across the solid solution series and establishing a conceptual model to characterize feldspar compression. Complex behavior has been observed in the Equation of State for plagioclase feldspars in excess of 3 GPa, including an anomalous softening of ordered albite in excess of 8.4 GPa (Benusa et al 2005: Am Min 90:1115-1120). This softening was not observed in the EoS for the more intermediate plagioclase compositions containing between 20 and 40 mol% of end-member anorthite. The calculated elastic compliance tensor sums at room pressure show a general stiffening with increasing anorthite component, small elastic changes at the C-1 to I-1 transition, and a dominantly first-order response at the P-1 to I-1 transition near end-member anorthite. The crystal structure of An37 plagioclase was determined by single-crystal X-ray diffraction. The compression mechanisms in An37 are similar to those in albite at lower pressures. The softening in albite at higher pressures is therefore attributed to the structural shearing in albite that is absent in An37 plagioclase up to 9.5 GPa. / Master of Science