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1
Bell, Joseph C. "Liquid-Liquid Equilibrium of Biodiesel Components." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3391.
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Biodiesel is produced from vegetable oils through transesterification. Triglyceride mixtures extracted from oilseed feedstocks are upgraded by reaction with an alcohol in the presence of a catalyst to produce fatty acid esters. This reaction produces a mixture of esters, glycerin, alcohol, and catalyst. Separation of the fatty acid esters (biodiesel) and glycerin can be accomplished through liquid-liquid extraction by water addition. Designing liquid-liquid extraction with water as the solvent requires ternary liquid-liquid equilibrium data for mixtures of water, glycerin, and fatty acid esters. Ternary mixture LLE data have been experimentally measured for several of these systems. Those measured include mixtures with the methyl esters of lauric, myristic, palmitic, stearic, and oleic acids. Data were collected at atmospheric pressure and 60°C. These ternary systems have been correlated using the NRTL equation. These data and correlation parameters can be used to improve separations efficiency in trans-esterified biodiesel fuels.
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Cheluget, Eric Lang̀at. "Equilibrium in aqueous liquid-liquid salt systems." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=39824.
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Experimental equilibrium phase diagrams, tie-lines and plait points were obtained for ternary systems consisting of water, sodium chloride and: 1-propanol at 298 K; n-dodecylammonium chloride at 303 K; poly(ethylene glycol) 8000 at 333 K; poly (propylene glycol)-425 at 278, 298 and 333 K; poly(propylene glycol)-725 at 278 and 298 K. For the 1-propanol and polymer systems, most of the salt was in the bottom phase while the nonionic solute was concentrated in the top phase. In the n-dodecylammonium chloride system the salt was evenly distributed between the phases while most of the surfactant was in the top phase. For the poly(propylene glycol) systems, the size of the region of two liquid phases increases with molecular weight and temperature.A modified form of the Flory-Huggins theory was developed for liquid-liquid equilibrium in binary aqueous systems of nonelectrolytes whose closed-loop phase diagrams contain both upper and lower consolute temperature points. The modification involved the assumption of an adjustable molecular size parameter $ chi sb{12}$. Calculations were performed for 15 aqueous binary systems. The models correlated the liquid-liquid equilibrium data accurately.
Liquid-liquid equilibrium in aqueous biphasic salt systems was modelled using an expression for the excess Gibbs energy of the solution. The expression is based on modified forms of the Mean Spherical Approximation, the Bromley equation, and the Flory-Huggins theory. The model requires 3 and 5 adjustable parameters for tenary and quaternary systems, respectively. The model accurately correlated vapor- and liquid-liquid equilibrium data for 8 ternary and 3 quaternary aqueous biphasic salt systems.
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Varanda, Fátima Rodrigues. "Measurement of liquid-liquid equilibrium of fluorous biphasic systems." Master's thesis, Universidade de Aveiro, 2007. http://hdl.handle.net/10773/2986.
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Mestrado em Engenharia QuímicaA catálise heterogénea é usada em 80% dos processos industriais catalíticos porque envolve uma fácil separação dos reagentes e produtos da reacção. A catálise homogénea, por sua vez, apresenta a grande vantagem de se poder usar diversos modelos capazes de descrever e prever as propriedades da mistura reaccional, embora apresente uma difícil separação e recuperação dos compostos envolvidos. A catálise bifásica consegue reunir as vantagens de ambos os tipos de catálise homogénea e heterogénea. Este método consiste em utilizar dois solventes imiscíveis a temperatura ambiente, onde o catalisador encontrase imobilizado em uma fase e os reagentes na outra. Através de um aumento da temperatura formase uma única fase onde ocorre a reacção. Ao arrefecer, as fases separamse permitindo a separação dos produtos e do catalizador, que pode ser reutilizado. Em particular, desde a primeira publicação, em 1994, que Horváth e Rábai demonstraram que os sistemas bifásicos fluorados podem ser altamente vantajosos em uma grande variedade de reacções químicas orgânicas, usando perfluorocarbonetos como meio de reacção. Este trabalho tem como principal objectivo o estudo do equilíbrio líquidolíquido de sete novos sistemas binários contendo compostos fluorados e solventes orgânicos, contribuindo com novos dados experimentais e teste de modelos nestes sistemas. O método utilizado foi a turbidimetria, usando um método dinâmico de detecção visual. Foram preparadas várias ampolas com composições diferentes para cada sistema. A mistura foi aquecida em um banho termostatizado a uma temperatura onde apenas uma fase era observada. Ao arrefecer lentamente essa mistura, observouse a separação das fases e a respectiva temperatura foi registada. Os resultados obtidos foram correlacionados coma dois modelos que usam diferentes abordagens. A equação de estado softSAFT foi utilizada para correlacionar os dados experimentais de forma satisfatória. O COSMORS, modelo baseado em cálculos de química quântica foi utilizado para prever o comportamento das solubilidades mútuas dos compostos envolvidos, tendose verificado uma ferramenta útil no caso de sistemas envolvendo tolueno e acetonitrilo.
Due to the easy separation of the reactants from reaction products, almost 80% of industrial catalytic reactions use heterogeneous catalysts. The homogeneous catalysis has the great advantage that models can be used to describe and predict the properties of the species involved in the catalytic reaction, but its main limitation is the separation and recovery of the products from the catalyst. The biphasic catalysis gather the advantages of both types of catalysis. This method consists on using two solvents which are immiscible at room temperature maintaining the catalytic system immobilized in one phase while the reactants and products remain in the other phase. By rising the temperature, the mixture becomes completely miscible allowing reactions to proceed homogeneously. On cooling, the phases separate allowing the facile catalyst/product separation. Since the first publication in 1994, by Horváth and Rábai, fluorous biphasic systems (FBS) have shown to have advantages in a wide variety of chemical organic reactions including catalytic reactions, using perfluorocarbons (PFC) as reaction media. The aim of this work is the study of liquidliquid equilibrium (LLE) of seven original binary systems containing highly fluorinated compounds and an organic solvent. This work contributes with new experimental LLE data of fluorous biphasic systems, measured using turbidimetry with naked eye visual detection. Several ampoules were prepared with different compositions for each system. The mixture was heated in a thermostatic bath until just one phase was observed. On slowly cooling, the phase separation temperature was registered. The obtained results were modeled using two different approaches. The softSAFT equation of state was used successfully to correlate the experimental data. COSMORS, a predictive method based on unimolecular quantum chemical calculations for individual molecules, was used to predict the phase behavior of the involved compounds and revealed to be a special useful tool in the case of toluene and acetonitrile mixtures.
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Alexander, Matthew Lucian. "Automation of an interfacial tensiometer." Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/11715.
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Wingard, David Belvin. "The relation of dynamic to equilibrium values of surfactant-induced interfacial tensions." Thesis, Georgia Institute of Technology, 1988. http://hdl.handle.net/1853/9380.
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Pinheiro, Regiane Silva. "Study of liquid-liquid extraction for methyl biodiesel purification process." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14103.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorIn the process of purification of biodiesel is of extreme importance washing methyl or ethyl ester rich- phase, since in conventional processes there is a great amount of water. During the washing is extracted primarily excess alcohol. Composition data for the washing process of biodiesel is still scarce in the literature and the study of liquid-liquid equilibrium provides the means to develop equipment and to optimize the extraction processes. Thus the main goal of this work is to determine equilibrium data for three different ternary systems: water - methanol - soybean biodiesel; corn biodiesel â methanol â water; methanol - coconut biodiesel - water at 20 Â C and 40 Â C. The experiments were carried out in equilibrium cells where the temperature was kept constant by thermostat control. The experimental determination was made by the method of densimetry. The consistency of data obtained for the tie lines was verified by correlations. It was verified by the ternary graphs, little influence of temperature on the systems studied. The equilibrium data were correlated liquid-liquid models for the activity coefficient NRTL, UNIQUAC and UNIFAC and proved quite satisfactory.
No processo de purificaÃÃo do biodiesel, a lavagem da fase rica em metil ou etil Ãster à de extrema importÃncia, visto que nos processos convencionais hà um grande gasto de Ãgua. Durante a lavagem à extraÃdo principalmente Ãlcool em excesso. Dados de composiÃÃes para a lavagem de biodiesel ainda sÃo escassos na literatura e o estudo do equilÃbrio lÃquido-lÃquido pode fornecer meios para o desenvolvimento de equipamentos e otimizaÃÃo dos processos de extraÃÃo. Dessa forma, o principal objetivo dessa dissertaÃÃo foi determinar dados de equilÃbrio lÃquido- lÃquido para os sistemas ternÃrios contendo biodiesel de soja + metanol + Ãgua, biodiesel de milho + metanol e Ãgua e biodiesel de coco + metanol + Ãgua, a 20 ÂC e 40 ÂC. Os experimentos foram feitos em cÃlulas de equilÃbrio mantendo a temperatura constante. A determinaÃÃo experimental das misturas ternÃrias foi feita pelos mÃtodos de titulaÃÃo e densimetria. A consistÃncia dos dados das linhas de amarraÃÃo foi verificada pelas correlaÃÃes de Othmer-Tobias e Hand. Verificou-se por meio de grÃficos ternÃrios, pouca influÃncia da temperatura sobre os sistemas estudados. Os dados de equilÃbrio lÃquido-lÃquido foram correlacionados pelos modelos para coeficiente de atividade NRTL, UNIQUAC e UNIFAC e mostraram-se bastante satisfatÃrios.
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Kurosawa, Izumi. "Solid-Liquid Equilibrium in Multi Solute Systems." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/4993.
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Solid-liquid equilibrium in isomorphous amino acid systems has been investigated as a model for systems that form solid solutions. Solid- and liquid-phase compositions in L-valine + L-leucine, L-valine + L-isoleucine, and L-isoleucine + L-valine in water were measured over the entire range of solid composition, and it was shown (from mass balance and phase rule considerations) that these systems form solid solutions. The solid- phases resulting from isothermal and cooling crystallization experiments were also investigated using powder x-ray diffractometry which showed that homogeneous solid solutions could only be obtained in cooling crystallization experiments, whereas isothermal experiments generally produced inhomogeneous solids. This suggests that data reported in the literature from isothermal experiments may not represent true equilibrium values. Solid-phase activity coefficients were estimated using binary and ternary equilibrium data and the UNIFAC-Kuramochi model for liquid-phase nonidealities. The solid phases in the three systems investigated exhibited significant nonidealities that were correlated using the Margules model. The model parameters exhibited a linear relationship with the ratio of binary solubilities of the two solutes. Such simple relationship may be advantageous when solid-liquid equilibrium of thermally unstable solutes or components with unknown physical properties are crystallized.
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Abdedou, Nazim. "Non-equilibrium conditions at solid/liquid interfaces." Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0346.
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Notre travail porte sur la fusion dite solutale survenant lorsque l'on met deux métaux en contact à une température comprise entre leurs températures de fusion respectives. L'interface solide/liquide se retrouve initialement fortement hors-équilibre et la cinétique propre à son retour à l'équilibre semble mettre en défaut les modèles généralement employés pour décrire la solidification et la fusion. Pour progresser dans la compréhension du processus, nous avons abordé le problème sous trois angles complémentaires. Dans un premier temps, nous avons réalisé des expériences in-situ de fusion solutale du système Au-Ag en utilisant la tomographie par rayons X. L'analyse critique des résultats semble montrer que l'interface solide-liquide reste hors équilibre pendant la fusion solutale, avec la persistance inattendue de gradients de concentration à la fin des expériences. Dans un deuxième temps, dans le but de mieux comprendre les expériences, nous avons mis en œuvre un modèle reposant sur la thermodynamique des processus irréversibles appliquée aux échanges d'espèces chimiques à travers une interface solide/liquide abrupte. Une paramétrisation des coefficients de transfert interfaciaux permet au modèle de reproduire qualitativement les comportements observés dans les expériences. Enfin, nous avons cherché à justifier les paramètres cinétiques du modèle thermodynamique en utilisant la dynamique moléculaire (DM) dans le système Cu-Ni. Nous avons ainsi démontré que les coefficients interfaciaux dépendent des concentrations à l'interface, en accord avec la paramétrisation du modèle thermodynamiqueOur work focuses on solutal melting, which occurs when two metals are brought into contact at a temperature between their respective melting temperatures. The solid/liquid interface is initially far from equilibrium, and the kinetics governing its return to equilibrium appear to challenge the models commonly used to describe solidification and melting. To advance our understanding of the process, we approached the problem from three complementary angles. First, we conducted in-situ experiments on the solutal melting of the Au-Ag system using X-ray tomography. Critical analysis of the results appears to indicate that the solid-liquid interface remains out of equilibrium during solutal melting, with the unexpected persistence of concentration gradients at the end of the experiments. Second, in an effort to better understand the experiments, we developed a model based on the thermodynamics of irreversible processes applied to the exchange of chemical species across a sharp solid/liquid interface. Parametrization of interfacial transfer coefficients enables the model to qualitatively reproduce the behaviors observed in the experiments. Finally, we sought to justify the kinetic parameters of the thermodynamic model using molecular dynamics (MD) in the Cu-Ni system. We thus demonstrated that the interfacial coefficients depend on the concentrations at the interface, consistent with the parametrization of the thermodynamic model
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Pence, David N. "Protein partitioning in two-phase liquid-liquid acetonitrile-water systems." Ohio : Ohio University, 1996. http://www.ohiolink.edu/etd/view.cgi?ohiou1178047340.
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Moeti, Lebone Tiisang. "The dependence of the continuous phase mass transfer coefficients on molecular diffusivity for liquid-liquid extraction in agitated vessels." Diss., Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/11856.
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Tsao, Joanna W. "Influence of nanoscale roughness on wetting behavior in liquid/liquid systems." Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53045.
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Wetting behavior of fluid/fluid/solid systems, largely influenced by surface properties and interactions between the three phases, plays a big role in nature and in industrial applications
Traditionally, wetting studies have focused on liquid/vapor systems, especially the study of a sessile liquid droplet in air. Liquid/vapor systems can only probe the effects of surface properties and interactions between the solid and the wetting liquid. This type of characterization is inadequate for liquid/liquid systems, where surface wettability is additionally influenced by interactions between the two wetting liquids.
The present study is the first to examine the effects of nanoscale roughness on wetting behavior in liquid/liquid systems and the modulation of roughness effects by fluid properties and the wetting order. This study examines both equilibrium and dynamic wetting behavior in liquid/liquid systems using well characterized substrates.
Rough substrates were fabricated by coating glass substrates with nanometer sized polymer particles. Partial dissolution of the particles and molecular de-deposition of the polymer allowed for tuning of substrate roughness while retaining the original surface chemistry. The effectiveness of this fabrication technique was verified using electron microscopy and electrokinetic analysis. We examined the wetting behavior in three fluid/fluid systems: an air/water system, a decane/water system, and an octanol/water system. The oils were chosen based on their different polarities.
Equilibrium wetting behavior was determined using contact angle measurements. Results indicate that for all systems where the primary wetting fluid was a liquid, an increase of the surface roughness resulted in Cassie-Baxter wetting. How hydrophilic a surface appears with regard to a water/fluid interface depended on the polarity of that fluid. The octanol/water system provided the strongest evidence regarding the effect of wetting order: a transition from Wenzel to Cassie-Baxter wetting was only observed when water was the primary wetting liquid. The observed transition was confirmed using a modified Wenzel/Cassie-Baxter model.
The kinetics of droplet spreading was measured using high speed optical microscopy. After a droplet was placed on a solid surface, the motion of the contact line was imaged at a rate of 1000 fps. The wetted area was then extracted using custom Matlab® scripts. The spreading kinetics underwent a transition between two regimes: a visco-inertial regime and a slower spreading regime. Results indicated that surface roughness influenced spreading kinetics in both regimes. The overall spreading rate was always slower for rough surfaces than for smoother surfaces. In liquid/liquid systems, the duration of visco-inertial regime was dependent on the surface roughness as well; in general, it was shorter for smooth substrates compared to rough substrates. Increasing the viscosity of the non-aqueous fluid significantly increased the duration of the visco-inertial regime and decreased the overall spreading rate.
This study provides insight into the competitive wetting of solid surfaces relevant in many industrial applications such as oil recovery or inkjet printing, and may guide the development of improved wetting models in an area that currently lacks an adequate theoretical description.
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Painter, D. M. "Kinetic and equilibrium studies at solid/liquid interfaces." Thesis, University of Salford, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384026.
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Blaylock, Charles Robert. "Statistical evidence for competing equilibria models in the system Tri-N-Butyl phosphate-nitric acid-water-diluent." Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/12030.
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Variankaval, Narayan. "Structure and thermodynamics of associating solutions : prediction of phase equilibria." Diss., Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/8304.
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Russell, Paul A. "Vapour-liquid equilibrium studies at atmospheric to moderate pressures." Thesis, Aston University, 1997. http://publications.aston.ac.uk/9605/.
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A study of vapour-liquid equilibria is presented together with current developments. The theory of vapour-liquid equilibria is discussed. Both experimental and prediction methods for obtaining vapour-liquid equilibria data are critically reviewed. The development of a new family of equilibrium stills to measure experimental VLE data from sub-atmosphere to 35 bar pressure is described. Existing experimental techniques are reviewed, to highlight the needs for these new apparati and their major attributes. Details are provided of how apparatus may be further improved and how computer control may be implemented. To provide a rigorous test of the apparatus the stills have been commissioned using acetic acid-water mixture at one atmosphere pressure. A Barker-type consistency test computer program, which allows for association in both phases has been applied to the data generated and clearly shows that the stills produce data of a very high quality. Two high quality data sets, for the mixture acetone-chloroform, have been generated at one atmosphere and 64.3oC. These data are used to investigate the ability of the new novel technique, based on molecular parameters, to predict VLE data for highly polar mixtures. Eight, vapour-liquid equilibrium data sets have been produced for the cyclohexane-ethanol mixture at one atmosphere, 2, 4, 6, 8 and 11 bar, 90.9oC and 132.8oC. These data sets have been tested for thermodynamic consistency using a Barker-type fitting package and shown to be of high quality. The data have been used to investigate the dependence of UNIQUAC parameters with temperature. The data have in addition been used to compare directly the performance of the predictive methods - Original UNIFAC, a modified version of UNIFAC, and the new novel technique, based on molecular parameters developed from generalised London's potential (GLP) theory.
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Chamupathi, Virittamulla Gamage. "Role of the interface in metal solvent extraction kinetics." Diss., The University of Arizona, 1987. http://hdl.handle.net/10150/184256.
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Interfacially active reagents are utilized in metal solvent extraction processes and it is therefore important to understand the role of the liquid-liquid interface in the study of the kinetics and equilibria of extraction. The diffusion problems encountered in the traditional apparatus were overcome by using a high speed stirring apparatus. The microporous teflon membrane phase separator permitted more accurate measurements of interfacial areas, characterization of extraction kinetics of metal chelates, and a greater understanding of the phase separation mechanism. In contrast to the neutral ligands, the anionic ligand of dithizones and substituted dithizones showed significant interfacial adsorption at the chloroform/water interface as monitored spectro-photometrically. Equilibrium studies on p-halodithizones indicated that the adsorption constant increased as the substituent was altered from chloro to bromo to iodo, and with the distribution ratio of the ligand. Kinetic studies on dithizone and p-iododithizone with Ni(II) and Zn(II) indicated that the extent of participation of the interface in solvent extraction kinetics of these metal ions is dictated by the interfacial activity of the extractant and the mechanisms of the rate limiting step in the bulk aqueous and interfacial regions.
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Siswana, Msimelelo Patrick. "Phase equilibria in three component systems alcohol-hydrocarbon-water." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1004988.
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The fuel industry in many parts of the world is blending alcohols with motor fuel either to extend the fuel or to improve its octane rating or both. Unfortunately alcohols are hygroscopic and as a result, water becomes a component of the fuel. This can lead to phase separation and the formation of a water-rich layer which could have serious corrosion consequences. In an attempt to understand the phase-splitting in alcohol-petrol-water blends, phase equilibria in ternary systems (alcohol-hydrocarbon-water) have been determined by experiment. The phase equilibria in these ternary systems are also discussed in terms of modern theories of liquid mixtures and the UNIQUAC theory is applied to the "ethanol + benzene + water" ternary system. The alcohols are all the C₁, C₂, C₃ and C₄ alcohols, and the hydrocarbons include those typically found in petrol, e.g. cyclohexane, benzene and substituted benzenes.
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Desai, G. H. I. "Measurement and correlation of vapour liquid equilibrium of heterogeneous systems." Thesis, Teesside University, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.374069.
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Hillen, Francis. "Improved method for VLE data reduction." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248601.
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Brown, Jacob Leslie. "Vapour-liquid equilibria within nanoporous media." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/277690.
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This thesis is dedicated to the exploration of fluid phases confined in nanoporous materials using Nuclear Magnetic Resonance (NMR) techniques, with an aim to benefit catalysis research. Included in this report are studies of pure fluids and their mixtures, confined in titania and silica catalyst supports. These investigations are conducted at industrially-relevant, high-temperature (≥ 180 °C) and high-pressure conditions (up to 13 bar), made possible by a pilot-scale chemical reactor unit, designed to operate inside the strong magnetic fields of an NMR spectrometer. NMR spectroscopy, relaxation and pulsed field gradient (PFG) diffusion experiments were performed on each of the systems discussed in this report. Cyclohexane was initially studied inside a porous titania catalyst support at 188 °C and various pressures up to 13 bar. The adsorption and desorption processes of the cyclohexane were observed, revealing a number of previously unobserved phenomena. In addition to an overall, averaged diffusion coefficient, a slow diffusion coefficient was observed within the PFG NMR data attributable to surface diffusive processes occurring within the material. Additionally, T1 relaxation studies were found to provide experimental evidence for the differing configurations of adsorbed layers on the adsorption and desorption branch of the isotherm. Cyclohexane was subsequently studied alongside fluorobenzene in a series of silica catalyst supports of 6 nm, 10 nm and 20 nm pore size. In doing this, it was hoped that the multiple phenomena observed in the titania experiments might be deconvoluted, allowing a greater level of insight. The diffusivities of the fluids were found to differ significantly between the materials, and greater evidence was found of the slow-diffusing surface phase in each of the materials. Additionally, concentrations of cyclohexane and fluorobenzene in the gas and adsorbed layers inside the pore space were calculated via the results of the PFG NMR experiments, providing a map of confined phase behaviour. Competitive adsorption effects were found to become more significant, the smaller the pore size of the material. The results of the cyclohexane and fluorobenzene in silica studies were modelled, using approaches available in the literature, which were found to give varying levels of prediction. The data set acquired in this thesis was found to provide a useful standard, against which current and future models of confined phase behaviour might be verified.
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Chan, Yik Chung. "Solubility measurement apparatus for rapid determination of solid-liquid equilibrium behavior /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?CBME%202008%20CHANY.
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Windmann, Thorsten [Verfasser]. "Vapor-liquid equilibrium properties from molecular simulation and experiment / Thorsten Windmann." Paderborn : Universitätsbibliothek, 2015. http://d-nb.info/1066295239/34.
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Tong, Danlu. "Development of advanced amine systems with accurate vapour-liquid equilibrium measurement." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9781.
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Imperative pressure on containing anthropogenic greenhouse gas (GHG) emissions, particularly CO2, has led to the development and deployment of low-carbon technologies across the globe. Carbon capture and storage (CCS) is widely considered as an indispensible part of the technology portfolio alongside energy efficiency, renewables and nuclear. Due to its operational flexibility and technology maturity, post-combustion capture (PCC) is most likely to be one of the first adopted capture processes. However, the associated capital expenditure (CAPEX) and operating cost (OPEX) of the current state-of-the-art PCC process are seemed as the major barriers for its commercialisation. This thesis investigated the relationship between the chemical structure of the amines and their CO2 cyclic loading capacity through solubility measurements with two types of apparatuses: a static-analytical apparatus and a static-synthetic setup. The former was first validated by measuring the solubility of CO2 in 30 mass% aqueous monoethanolamine (MEA) solutions at = T (313 and 393) K and a total pressure range between (11 and 415) kPa. After successful validation of the apparatus, new CO2 solubility data for a sterically-hindered amine, 2-Amino-2-Methyl-1-Propanol (AMP) were obtained at temperatures between (313 and 393) K and a total pressure range of (23 to 983) kPa. CO2 solubility data for a tertiary amine, 2-Dimethylaminoethanol (DMMEA) were also measured with the analytical apparatus from T = 313 K to T = 393 K and a total pressure of (6 to 616) kPa. Apart from the three single amines studied, this work investigated the blended amine systems and the influence of an activator (piperazine or PZ) on the promoted amines. For AMP + PZ blends, solubility measurements of CO2 in 25 mass% AMP + 5 mass% PZ and 20 mass% AMP + 10 mass% PZ were conducted from (313 to 393) K; while for the DMMEA + PZ mixture, 25 mass% DMMEA + 5 mass% PZ system was studied. The static-synthetic setup employed in this work was first validated through measuring the solubility of CO2 in water from (313 to 393) K. A calculation algorithm implemented in Microsoft Excel as VBA was used to convert the experimental data to Henry‘s constants which were then compared with literature data. After the validation, CO2 solubility of 25 mass% MDEA was measured at 313 K. Another aspect of this work involved building quasi-chemical thermodynamic models to interpret the experimental data obtained in both apparatuses. This work used two different methods including Deshmukh-Mather model based on activity (γ)-fugacity (φ) approach and a more simplified Kent-Eisenberg model to represent the single and mixed amine systems respectively. Despite the compromise in the correlation quality compared to the γ- φ approach, Kent-Eisenberg model has received wide popularity due to its simplicity. In this work, the correlation results from the two models were compared. The applications of the models to predict solution phase speciation and CO2 solubility behaviour not measured in this work were also discussed.
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Ian and 張志明. "Liquid Liquid Phase Equilibrium of Ionic Liquid." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/80205116782566320872.
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碩士國立清華大學
化學工程學系
89
Room temperature ionic liquid, which are nonvolatile, inflammable, and good solvation power, has attracted a lot of recent attention as a "green solvent" alternative. In this work, solid-liquid and liquid-liquid equilibria of [emim][PF6]+water and liquid-liquid equilibria of [bmim][PF6]+water are studied. UV was used to measure the solubility of ionic liquid in water phase. Karl-Fischer was used to measure the solubility of water in ionic phase. The solubility of [bmim][PF6] in water phase (2.36+0.08 wt% at 303 K to 3.67+0.2 wt% at 323 K) is less than that of [emim][PF6] and increases with increasing temperatures. The solubility of water in liquid [bmim][PF6] phase changes from about 2.70+0.03 wt% at 303 K to 3.70+0.03wt% at 323 K. While solubilities of ionic liquids in water are small, they are far from negligible. Hence cautions must be taken to prevent lost into environment when these chemicals are used. So we are conducting experiments to measure the partition of ionic liquids between water and biocompatible organic liquids such as 1-octanol and other alcohols. UV and TGA was used to measure the solubility of ionic liquid in water phase. GC was used to measure the solubility of 1-octanol in water phase. Karl-Fischer was used to measure the solubility of water in 1-octanol phase. TGA was also used to measure the solubility of ionic liquid in 1-octanol phase. But the solubility of 1-octanol in water phase and the solubility of ionic liquid in 1-octanol phase remained to be investigated.
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Huang, Chou Cheng, and 周正晃. "Liquid Liquid Equilibrium of Ternary System." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/43433199334269233648.
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Moodley, Suren. "Molecular simulation of vapour-liquid-liquid-equilibrium." Thesis, 2008. http://hdl.handle.net/10413/1653.
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Phase equilibrium data is vital for designing chemical separation equipment. Traditionally, such data is obtained through laboratory experiments by sampling and analysing each phase of an equilibrated chemical mixture. An alternative means of generating such data is via molecular simulations, which also gives insight into the microscopic structure of the phases. This project was undertaken due to the lack of work on molecular simulations in predicting vapour-liquid-liquid equilibrium (VLLE). Gibbs Ensemble Monte Carlo molecular simulations were performed in the isochoricisothermal (NVT) and isobaric-isothermal (NVT) ensembles to determine the ability and limitations of the Transferable Potentials for Phase Equilibria (United-Atom) and Extended Simple Point Charge (SPC-E) force fields in predicting three-phase fluid equilibrium for two binary and three ternary industrially relevant mixtures: n-hexane/water (1), ethane/ethanol (2), methane/n-heptane/water (3), n-butane/1-butene/water (4) and nhexane/ ethanol/water (5). The NPT ensemble proved inadequate for predicting VLLE for binary mixtures, as for both binary mixtures (1 and 2), the simulations reverted to two phases. This was due in part to the unlike-pair interactions between pseudoatoms in different molecules not being accurately predicted at the specified simulation conditions to reproduce experimental mixture densities and vapour pressures. It was also due to the sensitivity of the NPT ensemble to perturbations which probably removed the system from its three-phase trajectory in Gibbs phase space, since specifying even the correct pressure corresponding to the potential models was unsuccessful in obtaining stable VLLE. Furthermore, ternary VLLE could not be obtained for a mixture exhibiting an extremely narrow three-phase region (4) and simulations for a miscible, non-ideal mixture (5) gave mole fractions that were in poor agreement with experiment. Good results were obtained for mixture 3 which exhibits limited mutual solubilities and a large three phase region. The NVT ensemble overcame the shortcomings of the NPT ensemble by producing three stable phases for the binary mixtures, revealing that the three-phase pressures were shifted by as much as 12%. Also, the narrow three-phase region of mixture 4 was overcome by adjusting the total system volume, producing three stable phases. These were also the first successful binary VLLE simulations involving complex polyatomic molecules.Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2008.
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Lee, Bo-Hsuang, and 李伯軒. "Liquid-Liquid Phase Equilibrium of Ionic Liquids." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/69653803007215637782.
Full textAbstract:
碩士明志科技大學
化工與材料工程研究所
99
The purpose of this study was to measure the liquid-liquid equilibrium data of ionic liquids and to provide the data for simulation and design of related systems in the separation processes. In this study we measured the following terms of systems （1）1-butyl-3-methylimidazolium hexafluorophosphate（[Bmim][PF6]） + propyl acetate + propanol （2）1-butyl-3-methylimidazolium hexafluorophosphate + isopropyl acetate + 2-propanol （3）1-butyl-3-methylimidazolium chloride（[Bmim][Cl]） + propyl acetate + propanol （4）1-butyl-3-methylimidazolium chloride + isopropyl acetate + 2-propanol （5）1-hexyl-3-methylimidazolium chloride（[Hmim][Cl]） + propyl acetate + propanol （6）1-hexyl-3-methylimidazolium chloride-isopropyl acetate-2-propanol （7）1-octyl-3-methylimidazolium chloride（[Omim][Cl]） + propyl acetate + propanol （8）1-octyl-3-methylimidazolium chloride + isopropyl acetate + 2-propanol We used cloud point method to measure the solubility curve of the mixtures, then the tie-line can be find by using the density and refraction index of the composition of the mixtures, the data was measured at three different temperatures, 298.15 K, 308.15 K and 318.15 K. From the experiment results we can find that as the temperature increased, the two-phase zone of the three components was reduced. For the solubility of [Bmim][PF6], as the temperature increased, the solubility of the three components was relative low at 298.15 K, its solubility can reach 0.7 (mole fraction), but when the temperature increased to 318.15 K, the solubility decreased to about 0.5 (mole fraction). For the density, it was decrease when the temperature increased, also the refraction index was increase on the ionic liquid using [PF6] as anion and decrease when the ionic liquid using [Cl] as anion.
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Tadie, Margreth. "The design of two apparati to measure solid-liquid and liquid-liquid equilibria data." Thesis, 2010. http://hdl.handle.net/10413/3089.
Full textAbstract:
Two new apparati have been developed to measure solid-liquid and liquid-liquid equilibria via a synthetic visual method by determination of thermal signatures. One apparatus adopts a technique of using Peltier modules for cooling, and the other is a well-known design that uses a cryogenic fluid in a thermostatted glass cell for cooling of the sample. The Peltier design is for small sample volumes, with a 10 cm3 aluminium equilibrium cell and has a minimum operating temperature of 253.15 K. The glass design is developed to complement the Peltier and has a larger volume of 140 cm3 and a minimum operating temperature of 223.15 K. Both apparati have been semi-automated in order to increase the accuracy and improve the efficiency of data measurements. Therefore the experimenter no longer has to wait for many hours for the determination of equilibrium. This was done by incorporating software, which was specially designed for the apparati using Labview8TM, for controlling the cooling and heating rates. The uncertainty of the temperature measurements was found to be ±0.03 K for the Peltier apparatus and ±0.02 K for the Glass apparatus. Liquid-liquid equilibria data has also been measured on the Peltier apparatus, to demonstrate its versatility. This was done using a digital camera, controlled through the Labview software to identify cloud points. The results have been found to be comparable with literature values.
For solid-liquid equilibria new systems of n-alkyl carboxylic acid binary mixtures have also been measured: heptanoic acid + butyric acid and heptanoic acid + hexanoic acid. These systems were measured using both apparati and both systems exhibited eutectic behaviour. All eutectic temperatures were measured on the Glass apparatus. Experimental data for these systems was modelled using the local composition models: Wilson, NRTL and UNIQUAC models. The NRTL model was found to give the best results for both systems with root mean square deviations (RMSD) of 2.16 K and 1.27 K and absolute average deviations (AAD) of 0.61 K and 0.49 K, between temperature measurements of this work and those calculated from the models, for the heptanoic acid + butyric acid and heptanoic acid + hexanoic acid systems, respectively.Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2010.
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Chou, Tze-Zen, and 周子仁. "Study on the liquid-liquid equilibrium of electrolyte solutions." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/27936355039962013964.
Full textAbstract:
碩士國立臺灣科技大學
化學工程研究所
83
The objective of this study is to investigate the behavior of liquid-liquid equilibria of electrolyte solutions, including theoretical simulation and experimental studies. The experiments of liquid-liquid equilibria of electrolyte solutions were carried out for the systems of NPA-H2O-LiCl, NPA- H2O-NaCl, NPA-H2O-NaBr, NPA-H2O-KCl, NPA-H2O-CaCl2, IPA-H2 O-NaCl and IPA-H2O-CaCl2 at atmospheric pressure and 25℃. In the theoretical simulation, a model to correlate the liquid- liquid equilibria of electrolyte solutions has been developed. The activity coefficients of the solvents in the model were calculated by combining a Debye-Huckel-type term with a modified UNIQUAC equation. To describe the separation of liquid- liquid phases owing to the addition of electrolyte in the system, the Gibbs-Duhem equation was employed to calculate the mean activity coefficient of the electrolyte. Based on the mass balance, with an assumption for the chemical potential of the electrolyte at reference state, the mole fractions in both liquid phases can be calculated. In the correlation, only two adjustable parameters are needed. It was found that the theoretical simulation for most cases was in good agreement with the experimental data.
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Wang, Bo-Jyun, and 王柏鈞. "Liquid-Liquid Equilibrium of Caprolactam+MImSO4+Hydroxyl Group System." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/70493805366732116439.
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王嘉賢. "Vapor-Liquid Equilibrium of Nitrogen in Coal-Liquid Model Compounds." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/81191707976451728036.
Full textAbstract:
碩士國立臺北科技大學
化學工程系碩士班
91
A semi-flow type apparatus has been installed. By using this apparatus, we have measured the vapor-liquid equilibrium (VLE) data for the binary system of nitrogen with five coal-liquid model compounds, includes m-xylene, tetralin ,quinoline ,1-methylnaphthalene and diphenylmethane. The measurements were made at temperatures from 60 to 140℃ and pressures from 20 up to 80 bar. To check the new apparatus, the data of nitrogen + benzyl alcohol system were compared with those for the literature. The solubility of nitrogen in the liquid phase, as evidenced by the experimental results, increases with pressure and temperature. While the saturated gas phase composition (mole fraction) of coal-liquid component decreases with increasing pressure, but increases with increasing temperature. An empirical equation correlates well the saturated vapor compositions with the density of nitrogen. The VLE data were employed to determine the Henry’s constants with the Krichevsky-Ilinskaya ( KI ) equation. It showed the Henry’s constants decrease with increasing temperature for each system. The second virial cross coefficients (B12) have also been determined from the experimental data at low pressures. The Patel-Teja (PT)，Peng-Robinsion (PR) and Soave-Redlich-Kwong (SRK) equations of state with two different mixing rules were employed to correlate these new VLE data.
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Guo, You-Ren, and 郭祐任. "Liquid-Liquid Equilibrium and Separation Process for Ethylene Glycol Purification." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/hevwf3.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
103
The objective of this work is to design a separation process for purification of ethylene glycol. By using proper solvent to remove the impurity, 1,2-butanediol, from ethylene glycol. In the first step, the liquid-liquid equilibrium (LLE) and vapor-liquid equilibrium (VLE) data were measured. Using the thermodynamic model with the parameters determined from experimental data, we conducted steady-state simulation for the potential process. Finally, total annual cost (TAC) was taken as the objective function for the process optimization.
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Huang, Cho-Hao, and 黃卓浩. "Liquid-Liquid Equilibrium for Mixtures Encountered in Aromatics Separation Processes." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/14014157475377802720.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
97
Abstract The objective of this work is to determine the thermodynamic model parameters for accurately calculating the phase properties of mixtures containing paraffines + aromatics + sulfolane at liquid-liquid equilibrium (LLE). The LLE data of six ternary systems, including nonane + benzene + sulfolane, nonane + p-xylene + sulfolane, hexane + p-xylene + sulfolane, hexane + m-xylene + sulfolane, cyclohexane + p-xylene + sulfolane, and cyclohexane + m-xylene + sulfolane, were measured at temperatures ranging from 303.2 K to 323.2 K. The experimental results showed that two-phase region became smaller as increase of temperature. All the LLE data were correlated with the NRTL and the UNIQUAC models, respectively. The correlated results are satisfactory from these two models. Various versions of the UNIFAC model were also used to predict the LLE properties. Only UNIFAC-LLE model yielded reasonable resultes.
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LIN, BO-JIUN, and 林伯俊. "Liquid-Liquid Equilibrium Measurements of Ternary Systems of The Type." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/79071616397473106393.
Full textAbstract:
碩士國立臺灣大學
化學工程學研究所
89
ABSTRACT In this study; The liquid-liquid equilibrium measurements of two ternary system: water/ dodecane/ C4E1 and water/ tertradecane/ C4E1 at 25~45℃ were performed. Then doing the experimental data were numberically regressed with UNIQUAC MODEL. The nonionic surfactant CiEj is the abbreviation of CH3 (CH2)i-1 (OCH2CH2 )jOH, where "i" means the number of nonpolar hydrocarbon chains of hydrophobic groups and "j" is the number of hydrophilic groups. Gas chromatography method was applied to determine the composition of these liquid-liquid equilibrium systems, and the calibration error is within 0.5. The UNUQUAC interaction parameters were numerically regressed by minimizing the error ofcomposition. For the system with three- liquid- phase- coexisting, all the six interaction parameters can be solved directly from the compositions of three-liquid phase. The detail of regression procedure is discussed.
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Das, Chitra. "Liquid-Liquid Equilibrium Studies on Extraction of Commercially Significant Carboxylic Acids." Thesis, 2015. http://ethesis.nitrkl.ac.in/7990/1/2015_Liquid_Das.pdf.
Full textAbstract:
Carboxylic acids are commercially very important organic acids and their extraction from fermentation broth can be one of the sources of recycling back these important organic acids.Here, we have worked on two systems: experimental tie-line results and solubility (binodal) curves were obtained for the ternary systems of water + acetic acid + hexanol and water + caproic acid + methyl isobutyl ketone at temperature of 308K and at atmospheric pressure. The concentrations of the components in the equilibrium phases were measured using gas chromatography for hexanol and methyl isobutyl ketone and acid concentration in each phase was determined by titration against NaOH solution. The water concentration was determined using mass balance. Using the equilibrium tie line phase compositions graph was plotted for the ternary systems. Solubility or binodal curves were obtained by joining these tie line phase compositions. The two phase and the one phase region were then determined for the ternary systems. Distribution coefficients and separation factors were calculated for the ternary systems to determine whether the solvents used were suitable for extraction of those specific organic acids from their aqueous phases.
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Hwengwere, Alex P. "Vapour-liquid equilibrium of carboxylic acids." Thesis, 2005. http://hdl.handle.net/10413/2737.
Full textAbstract:
VLE data is essential for the design and optimisation of industrial separation processes. Carboxylic acids are of significant interest because of their importance in both industrial and biological processes. Carboxylic acids are used as raw materials for a wide range of products, which include soaps , detergents, nylon , biodegradable plastics, medical drugs and food additives, They are also used both as solvents and as additives and co solvents under a wide range of conditions. Carboxylic acids exhibit strong self and cross -association through hydrogen bonds in both liquid and vapour phases. A thorough understanding of how these molecules interact both with themselves and with other solvents becomes necessary if existing processes may be optimised and new processes developed. Vapour-liquid equilibrium (VLE) data were measured for carboxylic acid systems ranging from C3 to C6• New vapour-liquid equilibrium data were measured for the following binary carboxylic acid systems: • Propionic acid + Hexanoic acid at 20 kPa, 403.15 K, 408.15 K and 413.15 K. • Isobutyric acid + Hexanoic acids at 20 kPa, 413.15 K and 423.15 K. • Valerie acid + Hexanoic acid at 15 kPa, 423 .15 K and 433.15 K. • Hexanoic acid + Heptanoic acid at 10 kPa and 443.15 K. A highly refined dynamic VLE Still by Raal (Raal and Muhlbauer [1998]) was used to undertake the VLE measurements. The still was operated either isothermally or isobarically using a computer control scheme. The isobaric and isothermal control was measured to be ±0.03 kPa and ±0.02 K respectively. The experimental procedure was verified with the highly volatile cyclohexane (l) + ethanol (2) system. The cyclohexane (l) + ethanol (2) measured VLE data was found to be in good agreement with that of Joseph (2001) and passed both the direct test and point test for thermodynamic consistency. A high degree of confidence was then placed on the equipment set-up and experimental procedure, as well as the new carboxylic acids VLE data . The VLE data for all the systems measured were modelled. Two data reduction methods were used: I. The combined ( r- ¢ ) method u. The direct method (¢ - ¢ ) method. In the combined method, the vapour phase non-idea lity was corrected using the Pitzer-Curl (1957) correlation and the Hayden and O' Connell (1975) chemical theory approach. Three liquid phase activity coefficient models were used namely the Wilson, NRTL, and UNIQUAC equations. The Peng-Robinson equation of state (Peng and Robinson [1976]) in combination with the Twu and Coon mixin g rule was used in the direct method. Thermodynamic consistency tests were done on all the systems measured. The point test (Van Ness et a!. [1973]) and the direct test Van Ness ([ 1995]) were used for consistency tests . The direct test could not be carried out on the carboxylic acids data because of the model's inability to adequately characterise the experimental activity coefficients. Generally the models fitted the data well but failed to accurately predict the "S" shape of the carboxylic acids phase diagrams. Considerable work still exists for further investigation into carboxylic acids. Currently, many experimentalists are working in this area . Penget a!. (2004) present ed their progress on developing an equation of state incorporating chemical theory to specifically handle carboxylic acids at the ICCT conference in Beijing, 2004. Raal and Clifford (University of Kwa-Zulu Natal, Thermodynamics Research Unit) are currently developing activity coefficient models incorporating chemical theory for a binary mixture of carboxylic acids. This work is part of the continuing research to under stand the phase behaviour of carboxylic acids.Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2005.
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You, Ming Long, and 尤明隆. "Application of a new equation of state in vapor-liquid and liquid-liquid phase equilibrium calculations." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/48539481934909246879.
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Tetrisyanda, Rizky, and 安芮琪. "Liquid-Liquid Equilibrium of Aqueous Mixtures Containing 2-Methylfuran or Alkyl Levulinates." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/25728991354563735719.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
102
Separation and extraction process is an important industrial process. It is often applied in many industries. Liquid-liquid equilibrium data are needed for rational design and optimal separation operation. The objective of this study is to determine liquid-liquid equilibrium (LLE) for aqueous binary and ternary mixtures containing furfuryl alcohol, 2-methylfuran or alkyl levulinates (ethyl levulinate and butyl levulinate) at 238.15 K – 328.15 K under atmospheric pressure. Organic compounds such as 2-methylfuran, ethyl levulinate and butyl levulinate are partially miscible with water and two liquid phases are formed in these aqueous mixtures. The reliability of the experimental tie-line data was satisfactorily ascertained by the Othmer-Tobias correlation. The experimental LLE tie-line data were also accurately correlated with the NRTL and the UNIQUAC models.
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Chen, Chang-Chiuan, and 陳昶全. "Liquid-Liquid Equilibrium for Mixtures Containing Water, Acrylic Acid, Alcohols and Acrylates." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/23925989828889964444.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
93
The objective of this work is to experimentally deterimine the liquid-liquid equilibrium (LLE) data for simulation and design of reactive distillation tower.The LLE data of five ternary systems, including water + acrylic acid + n-butyl acrylate, water + n-butanol + n-butyl acrylate, water + acrylic acid + n-butanol, water + ethanol + ethyl acrylate and water + acrylic acid + ethyl acrylate were measured at temperatures ranging from 283.15 K ~ 318.15 K. When temperature rises, two-phase region of all systems would become smaller, but this effect is not apparaent.The NRTL-HOC model and the UNIQUAC-HOC model were used for the prediction of phase equilibrium behavior. The UNIQUAC-HOC model is found to be better than the NRTL-HOC model. This study also used various vesion of the UNIFAC model to predict the new data, but the results were not as good.
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Ndlovu, Mkhokheli. "Development of a dynamic still for measuring low pressure vapour-liquid-liquid equilibria : systems of partial liquid miscibility." Thesis, 2005. http://hdl.handle.net/10413/2775.
Full textAbstract:
The dynamic still originally designed by Raal (Raal and Muhlbauer [1998]) has been transformed into a valuable still that can now be used for measuring both low pressure vapour-liquid equilibria (VLE) for systems that are completely miscible and vapour-liquid-liquid equilibria (VLLE) for systems that are partially miscible. The resultant equilibrium data are important in the design and analysis of distillation and allied separation process equipment, with VLLE data, in particular, being useful in the design of heterogeneous azeotropic distillation columns. The original Raal still was based on the designs of Heertjies [1960] and Yerazunis [1964], who successfully used a packed equilibrium chamber where the liquid and vapour phases are forced downward co-currently to achieve rapid and dynamic equilibrium (Joseph et al [2001]). Direct analysis of the vapour composition prior to condensation through a new heated valving system with superheated sample conveyance to a gas chromatograph, a modification incorporated into the Raal still, ensured that accurate and reproducible equilibrium data were obtained. This new arrangement dispenses with the impossible task of getting the actual vapour composition that would result were the vapours allowed to condense and form two liquid phases. The initial testing of the still which established the operating procedures was conducted on two previously measured systems - the first which was homogeneous and the second heterogeneous. For the homogeneous system the new vapour sampling system was tested by comparing the measured composition to that of a condensed sample sent manually to the GC using a gas-tight syringe. In order to completely describe the VLLE for the systems studied, the liquid-liquid equilibrium (LLE) data for these systems were also measured. The LLE measurements were conducted in a newly-developed small jacketed glass cell with temperatures maintained constant by circulating water from a bath maintained at the desired temperatures. The main focus of this project was thus the development of an apparatus and procedures for measuring low pressure vapour-liquid-liquid equilibria. The project also went on to measuring and modeling VLE, VLLE and LLE data for selected binary and ternary systems. Both the Gamma-Phi and the Phi-Phi methods of VLE analysis were carried out on the measured data. The NRTL, Wilson, TK-Wi1son and UNIQUAC activity coefficient models were used in the Gamma- Phi method together with the Virial equation of state for vapour phase non-idealities. In the Phi-Phi method, The Peng and Robinson Equation of State (EOS), the Soave Redlich-Kwong EOS and the Stryjek and Vera modified Peng and Robinson EOS were all used, first with the classical mixing rules and then with the theoretically correct Wong and Sandler [1992] mixing rules. Ternary LLE binodal curves were correlated to the Hlavaty correlation, the beta function and the log gamma function while the corresponding tie-lines were fitted to the NRTL model.Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2005.
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Hu, Ho-Hsun, and 胡賀勛. "Liquid-liquid equilibrium measurements of ternary systems of the type water+oil+surfactant." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/00405175103915944234.
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碩士國立臺灣大學
化學工程學系
86
Surfactants play an important role in chemical engineering industry. Besides the use of emulsification and detergent, they are espe cially effectively used in the tertiary oil recovery. The liquid-liquid extraction technology requires the liquid-liquid equilibrium composition data of the ternary system of water-oil-surfactant. This study offers experimental data of equilibrium for two ternary systems. We measure the two ternary system:H2O~n- dodecane~diethylene glycol monohexyl ether (C6E2) and H2O~n-tetradecane~C6E2 at two dif ferent temperatures 20℃ and 30℃. In addition to the traditional gas chromatography, we use the Karl-Fisher moisture titrator to determine the water content as well. One three-phase re gion and three two-phase regions are found for these two systems. With rising the temperature, the surfactant-rich phase composition gets closer to the oil-rich phase composition. That means the surfactant moves from the water-rich phase toward the oil-rich phase as the tempera ture is increased. We also find that the tempera ture has stronger effect on the system containing n-dodecane than on the system containing n- tetradecane. At last we correlate the experimental results by the UNIQUAC model. Although the correlated results are not good enough, the existence of the three phase region are successfully calculated. Due to the diffi culty of numerical analysis, it is believed that the calculated result we get only coincides with the local minimum, not the global minimum in this highly nonlinear regression calculations. Therefore, the bet ter interaction parameters should be resolved by designing a more efficient regression technique.
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Pai, Yung-Hsiang, and 白永祥. "Liquid-Liquid Equilibrium Measurements of Ternary Systems of The Type Water+Alcohol+Surfactant." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/19292717816602624608.
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碩士國立臺灣大學
化學工程學系
86
In this study, we analyze the liquid-liquid equilibrium composition data of the two component systems: water/n-pentanol and water/2-methyl-2-butanol at 10-80℃with gas chromatography and use the UNIQUAC equation to correlate these data. The relation between the UNIQUAC interaction parameters and temperature are fitted with second and third order polynomial equations. The standard deviation of the calculated equilibrium composition is within 0.002. In addition, we also perform the measurement of liquid-liquid equilibrium composition data of two three-component systems: water/n-pentanol/C4E1 and water/2-methyl-2-butanol/ C4E1 at 20 and 30℃. C4E1 is the abbreviation of the nonionic surfactant . The equilibrium tie line and composition of each phase are used to regress the UNIQUAC interaction parameters in sequence. With the use of these parameters, the tendency of tie line and binodal curve of these three-component systems described by the UNIQUAC equation is in a good agreement with that of the experimental data. The average error of equilibrium tie line between the calculated and experimental data is within 0.009.
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Teng, Han-Lan, and 鄧翰嵐. "Liquid-Liquid Equilibrium of Aqueous Solutions in the Presence of Biological Buffer EPPS." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/43086613360966517114.
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碩士國立臺灣科技大學
化學工程系
99
The objective of this study is to investigate the liquid-liquid phase equilibrium behavior of organic aqueous systems containing a biological buffer 3-[4-(2-hydroxyethyl)-1-piperazinyl]propanesulfonic acid (EPPS). The studied aqueous systems including one of following organic compounds：1-propanol, 2-propanol, tert-butanol, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, or acetonitrile. A new liquid phase was formed when we added certain amount of EPPS into the above mentioned aqueous solutions. The liquid-liquid equilibrium (LLE) and solid-liquid-liquid equilibrium (SLLE) data were measured for these ternary aqueous systems at 298.2 K under atmospheric pressure. The effective excluded volume (EEV) values of EPPS were obtained from the phase boundary data. The results of Othmer-Tobias illustrated that the LLE experimental data appear to be well-consistent. The experimental tie-lines data were correlated satisfactionly with the NRTL model. The buffering-out effect may be useful in the recovery of organic solvent from the aqueous solutions.
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ZHANG, REN-YAO, and 張仁耀. "Expert system for vapor-liquid equilibrium predictions." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/08521806938793114079.
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Lin, Chun peng, and 林群朋. "Liquid-Liquid Equilibria and Equilibrium Physical Properties for Mixtures of Water, Methanol, Dimethyl carbonate, n-Heptane, and Toluene." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/51284591479048952403.
Full textAbstract:
碩士靜宜大學
應用化學系
99
This study measures the liquid-liquid equilibria (LLE) for one quaternary system [water + methanol + (n-heptane 50 mol% + toluene 50 mol%)] and three quinary systems [water + (methanol 75 mol% + dimethyl carbonate 25 mol%) + (n-heptane 50 mol% + toluene 50mol%), water + (methanol 50 mol% + dimethyl carbonate 50 mol%) + (n-heptane 50 mol% + toluene 50 mol%), and water + (methanol 25 mol% + dimethyl carbonate 75 mol%) + (n-heptane 50 mol% + toluene 50 mol%)]. The experiments were conducted at 298.15 K and 313.15 K under atmospheric pressure. The reliability of the experimental tie-line data was confirmed using the Othmer-Tobias equation. The experimental tie-lines data were correlated with the NRTL and the UNIQUAC models obtaining a well reproducibility of the experimental phase equilibrium behavior. The densities, viscosities, refractive indexes, and surface tensions of each conjugated phase located in the isothermal binodal curve have been determined for the multicomponent systems. It is observed that these data of each conjugate phase are valuable references for the degree of mutual solubility of the multicomponent systems.
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Chen, Chan-An, and 陳俊安. "Liquid-Liquid Equilibria and Equilibrium Physical Propreties for Mixtures of Water,Methanol,Diethyl Carbonate,Cyclohexane and P-Xylene." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/62221040790498039238.
Full textAbstract:
碩士靜宜大學
應用化學系
99
Experimental liquid-liquid equilibrium (LLE) data are presented for one quaternary systems water + methanol + (cyclohexane 50mol% + p-xylene 50mol%). The LLE data were also reported for three quinary systems water + (methanol 75mol% + diethyl carbonate 25mol%) + (cyclohexane 50mol% + p-xylene 50mol%). water + (methanol 50mol% + diethyl carbonate 50mol%) + (cyclohexane 50mol% + p-xylene 50mol%) and water + (methanol 25mol% + diethyl carbonate 75mol%) + (cyclohexane 50mol% + p-xylene 50mol%). The experiments were conducted at 298.15 and 318.15 K under atmospheric pressure. Each system exhibited a large partially miscible region and the region of heterogeneity was found to decrease with an increase of temperature. These new LLE data were correlated with NRTL and UNIQUAC models obtaining a very good reproduction of the experimental behavior. The densities, viscosities, refractive indexes, and surface tensions of each conjugated phase located in the isothermal binodal curve have been determined for the multicomponent systems. It is observed that these data of each conjugate phase are valuable indicators for the degree of solubility of the multicomponent systems.
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Jiang, Xinlei, and 江鑫磊. "Liquid-Liquid Equilibria And Equilibrium Physical Properties For Mixtures Of Water, Methanol, Tert-Butanol, Methylcyclohexane, And p-Xylene." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/52449637998322683174.
Full textAbstract:
碩士靜宜大學
應用化學系
100
In this study, the liquid-liquid equilibria (LLE) for the multicomponent systems of water + methanol + tert-butanol + methylcyclohexane + p-xylene were conducted at 298.15 K and 318.15 K respectively. The liquid-liquid equilibria of the multicomponent systems investigated are : water + methanol + (methylcyclohexane 50mol％ + p-xylene 50mol％), water + (methanol 75mol％ + tert-butanol 25mol％) + (methylcyclohexane 50mol％ + p-xylene 50mol％), and water + (methanol 50mol％ + tert-butanol 50mol％) + (methylcyclohexane 50mol％ + p-xylene 50mol％), water + (methanol 25mol％ + tert-butanol 75mol％) + (methylcyclohexane 50mol％ + p-xylene 50mol％), water + tert-butanol + (methylcyclohexane 50mol％ + p-xylene 50mol％) were studied. The compositions of liquid phases at equilibrium were determined by g.l.c. measurements. The experimental LLE data of the multicomponent systems were correlated with the NRTL and UNIQUAC solution models with satisfactory results. The multicomponent systems are depicted as the ternary mixtures and the phase diagrams in the form of Gibbs triangles with both the experimental and calculated tie-lines are presented. The solubility curve data for the studied multicomponent systems were determined by the cloud point method and are successfully correlated using an empirical equation. The reliability of the experimental tie-line data was confirmed using the Othmer-Tobias equation. Each system exhibited a large partially miscible region. The region of heterogeneity was found to decrease with an increase of temperature or blending of tert-butanol with methanol. The water composition in the organic phase and the hydrocarbon solubility in the aqueous phase at the different temperature are illustrated in terms of the sum (methanol+tert-butanol) in the global composition. The water composition in the organic phase and the hydrocarbon solubility in the aqueous phase were found to increase with an increase of the amount of tert-butanol or an increase of temperature. The densities, viscosities, refractive indexes, and surface tension of each conjugated phase located in the tie-lines have been determined for the multicomponent systems. It is observed that these data of each conjugate phase are valuable indicators for the degree of solubility of the multicomponent systems. These observations may be important when appraising both the water pollution potential of possible gasoline reformulations and sensitivity of the gasoline to water.
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Xhakaza, Nokukhanya Mavis. "Liquid-liquid equilibria related to the separation of organic acids." Thesis, 2012. http://hdl.handle.net/10321/703.
Full textAbstract:
Submitted in fulfilment of the requirements of the Masters Degree in Technology: Chemistry, Durban University of Technology, 2012.The thesis involves a study of the thermodynamics of ternary liquid mixtures involving carboxylic acids with sulfolane, hydrocarbons and acetonitrile. Carboxylic acids are an important group of polar compounds with many industrial and commercial uses and applications. In South Africa, these carboxylic acids together with many other oxygenates and hydrocarbons are manufactured by SASOL using the Fischer–Tropsch process. The separation of these acids from hydrocarbons is a commercially viable option, and is an important reason for this study. This work focuses on the use of sulfolane in effecting separation by solvent extraction and not by the more common and energy intensive method of distillation. Sulfolane was chosen because of its high polarity and good solvent extraction properties. The first part of this study involves the determination of excess molar volumes (VmE) of binary mixtures of sulfolane (1) + carboxylic acids (2) at different temperatures of 303.15 K and 308.15 K, where carboxylic acids refer to acetic acid, propanoic acid, butanoic acid, 2-methylpropanoic acid, pentanoic acid and 3-methylbutanoic acid respectively. The densities of the binary systems of sulfolane (1) + carboxylic acids (2) were measured at T = 303.15 K and 308.15 K. The excess molar volumes were calculated from the experimental densities at each temperature. The VmE were negative for the entire mole fractions for all the binary systems. It was found that the VmE in the systems studied increase with an increase in temperature, and also VmE decreases with an increase in the carbon chain length of the carboxylic acid. The VmE data results were correlated using Redlich-Kister equation. Abstract ii The second part was the study of the binodal or solubility curves and tie line data for the ternary systems of [sulfolane (1) + carboxylic acids (2) + hydrocarbons (3)] and [acetonitrile (1) + carboxylic acids (2) + hydrocarbon (3)]. Hydrocarbons refer to pentane, hexane, dodecane and hexadecane. The binodal curve experimental data was determined by the cloud point technique. Liquid-liquid equilibrium (LLE) phase diagrams were constructed using the mole fractions and refractive indices (nD). Tie line data were obtained for the sulfolane-rich and hydrocarbon-rich phases as well as the acetonitrile-rich and hydrocarbon-rich phases respectively. The tie lines in both cases were skewed towards the hydrocarbon-rich phases indicating that relative mutual solubility of carboxylic acids is higher in the hydrocarbon-rich phase than in the solvent-rich phase. Selectivity values were calculated from the tie-lines to determine the extraction capabilities of solvents sulfolane and acetonitrile. Selectivity values in all cases were greater than one, meaning that both sulfolane and acetonitrile can be used to separate carboxylic acids from hydrocarbons. Binodal curve data were correlated by the Hlavatý, beta (𝛽) and log𝛾 equations; average standard deviation error for Hlavatý was 0.012, for beta (𝛽), 0.023 and for log𝛾, 0.021. The NRTL and UNIQUAC models were used to correlate the experimental tie-lines. The calculated values based on the NRTL equation were found to be better than those based on UNIQUAC equation; the average root-mean square deviation, (rmsd), between the phase composition obtained from experiment and that from calculation was 0.061 for the NRTL model, as compared to 0.358 for UNIQUAC model for the ternary systems involving sulfolane. For ternary systems of acetonitrile, the NRTL equation was better than the UNIQUAC with the rsmd of 0.003 and 0.287for UNIQUAC equation.
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Fang, Mei-Yueh, and 方玫月. "Liquid-Liquid Equilibrium of Aqueous Solutions in the Presence of Biological Buffer HEPES-Na or Ionic Liquid [TMA][EPPS]." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/73452108535981166944.
Full textAbstract:
碩士國立臺灣科技大學
化學工程系
101
The main objective of this study is to investigate liquid-liquid equilibrium (LLE) behavior of azeotropic organic aqueous solutions in the present of biological compatible buffer (HEPES-Na) or new ionic liquid ([TMA][EPPS]) at 298.2 K and atmospheric pressure. The organic solvents of 1,3-dioxolane, 1,4-dioxane, acetonitrile and tert-butanol were studied in this work. As the third component, buffer or ionic liquid, was added, the ions of buffer or ionic liquid would form strong interactions with water; therefore, the mixtures would be divided into two-liquid phases, aqueous phase and organic phase. The phase boundary data were measured by cloud point and the LLE data by analytical method. The consistency of the tie-line data was confirmed by the Othmer-Tobias correlation. The LLE data were correlated with the NRTL model and the optimal interaction parameters were obtained by the data reduction.
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Chen, Poyo, and 陳柏宇. "Liquid-Liquid Equilibria and Equilibrium Physical Properties for Mixtures of Water, Methanol, 2-Propanol, 2,2,4-Trimethylpentane, and p-Xylene." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/37408282621053428982.
Full textAbstract:
碩士靜宜大學
應用化學系
101
In this day, the liquid-liquid equilibria (LLE) for the quinary system of water + methanol + 2-propanol +2,2,4-trimethylpentane + p-xylene were conducted at 298.15 K and 318.15 K respectively. The liquid-liquid equilibria of the multicomponet systems investigated are: water + methanol + (2,2,4-trimethylpentane 50mol% + p-xylene 50mol%), water + (methanol 75mol% + 2-propaol 25mol%) + (2,2,4-trimethylpentane 50mol% + p-xylene 50mol%), water + (methanol 50mol% + 2-propaol 50mol%) + (2,2,4-trimethylpentane 50mol% + p-xylene 50mol%), water + (methanol 25mol% + 2-propaol 75mol%) + (2,2,4-trimethylpentane 50mol% + p-xylene 50mol%), water + 2-propaol + (2,2,4-trimethylpentane 50mol% + p-xylene 50mol%) were studied. The liquid-liquid phases after equilibrium were determined by g.l.c. measurements. The experimental LLE data of the multicomponent systems were correlated with the NRTL and UNIQUAC solution models with satisfactory results. The multicomponent systems are depicted as the ternary mixtures and the phase diagrams in the form of Gibbs triangles with both the experimental and calculated tie-lines are presented. The solubility curve data for the studied multicomponent systems were determined by the cloud point method. The reliability of the experimental tie-line data was confirmed using the Othmer-Tobias equation. Each system exhibited a large partially miscible region. The region of heterogeneity was found to decrease with an increase of temperature or blending of 2-propanol with methanol. The water composition in the organic phase and the hydrocarbon solubility in the aqueous phase at different temperatures are illustrated in terms of the amount of (methanol+2-propanol) in the global composition. The water composition in the organic phase and the hydrocarbon solubility in the aqueous phase were found to increase with an increase of the amount of 2-propanol or an increase of temperature. The densities, viscosities, refractive indexes of each conjugated phase located in the tie-lines have been determined for the multicomponent systems. It is observed that these data of each conjugate phase are valuable toward the understanding of the degree of solubility of the multicomponent systems. These observations may be important when appraising the water pollution potential of gasoline reformulations and the sensitivity of the gasoline to water.