Methyl Acetate Synthesis
Molar Heat Capacity (cP) of Acetic acidFluid Phase Equilibria v. This work reports new density data points methyl acetate vapor pressure curve 1-butanol at mehhyl temperatures between The experimental density data were fitted with the Tait-like equation with low standard deviations. In addition, the isobaric thermal expansivity and the isothermal compressibility have been derived from the Tait-like equation. Prediction of thermodynamic, transport and vapor—liquid equilibrium properties of binary mixtures of ethylene glycol and water by Jianxing Dai; Ling Wang; Yingxin Sun; Lin Wang; Huai Sun
Fluid Phase Equilibria v. This work reports new density data points of 1-butanol at twelve temperatures between The experimental density data were fitted with the Tait-like equation with low standard deviations.
In addition, the isobaric thermal expansivity and the isothermal compressibility have been derived from the Tait-like equation. Prediction of thermodynamic, transport and vapor—liquid equilibrium properties of binary mixtures of ethylene glycol and water by Jianxing Dai; Ling Wang; Yingxin Sun; Lin Wang; Huai Sun The properties predicted include density, vaporization enthalpy, enthalpy of mixing, heat capacities, diffusion coefficients, shear viscosities, thermal conductivities, vapor—liquid coexistence isotherms and isobaric curves, and saturation vapor pressures.
Good agreements with experimental data were obtained for most of these properties. Errors are mostly related to inaccuracy found in predictions of pure fluids; a correction to prediction of pure substance can systematically improve prediction for the mixture.
Thermodynamic properties; Transport properties; Molecular simulation; Mixture;. Thermodynamics of mixtures containing oxaalkanes. From values of the molar excess enthalpies at infinite dilution obtained from H m E data available in the literature, it is concluded that the increase of the number of —O— atoms in the ether or cyclization leads to stronger interactions between unlike molecules.
Values of the Kirkwood—Buff integrals and of linear coefficients of preferential solvation reveal that the structure of the investigated systems is close to random mixing. Effect of sodium caproate on the volumetric and conductometric properties of glycyl- l -glutamine and l -alanyl- l -glutamine in aqueous solution at An increase in transfer volumes and a decrease in hydration numbers of the glutamine dipeptides with increasing sodium caproate concentration have been explained due to stronger interactions of sodium caproate with the charged center and polar groups of the glutamine dipeptides compared to the sodium caproate-nonpolar group of dipeptide interactions.
Both the hydration number for glutamine dipeptides and Walden products values in peptide—sodium carboxylate—water systems are in the order: This can be ascribed to the fact that the interactions of dipeptides with sodium carboxylate increase with the increase in the size of side chain of carboxylate anions.
Glycyl- l -glutamine; l -Alanyl- l -glutamine; Sodium caproate; Standard partial molar volume; Conductivity;. Breil; Christina Vogelpohl; Gabriele Sadowski The chromatographic retention in hydrophobic and reversed phase chromatography and the solubility of proteins display some common features. The chromatographic retention, as well as the solubility, is modulated by the thermodynamic properties of the solute in the fluid phase.
The retention measurements at linear conditions provide information of the solution properties of the protein at infinite dilution, and the solubility measurements produce the supplementary information about the solution properties at the saturation limit.
This provides a useful approach to simultaneous correlation of the chromatographic retention and the solubility. The experimental data, used for the correlation, comprise retention measurements of lysozyme on different HIC adsorbents using an aqueous ammonium sulphate eluant, an aqueous ammonium sulphate eluant with an admixture of ethanol, as well as published solubility data.
The chromatographic retention data and the corresponding solubility data have been correlated using a chemical potential model derived from Kirkwood's theory of solutions of charged macro-ions and zwitterions in electrolyte solutions. The model correlated the chromatographic retention factor and the solubility data within the precision of the measurements. The model was applied in a pH range from 4 to It was demonstrated experimentally, as well as theoretically, that an admixture of ethanol to the aqueous eluant changes the thermodynamic retention factor on various adsorbents identically when compared to the thermodynamic retention factor in an ethanol free eluant.
In this paper, a set of experimental data on the phase equilibrium of gas hydrates in the presence of binary gas mixtures comprising CO 2 is presented. The procedure established allows for the determination of both the composition of the gas phase as well as the hydrate phase without the need to sample the hydrate. The experimental results obtained in these measurements have been described by means of the classical model of van der Waals and Platteeuw. The values of internal parameters of the reference state and the Kihara parameters have been re-discussed and their interdependency is pointed.
Finally the new set of parameters is validated against experimental data from other sources available in the literature, or invalidated against other sources.
Finally, we conclude on the difference of experimental data between laboratories. The differences are not on the classical pressure, temperature, gas composition data which appear equivalent between laboratories. The difference stands on the measurement composition of the hydrate phase.
Gas hydrates; Thermodynamic; Crystallization; Modelling;. The phase behavior of fluid mixtures is understood by the critical lines in fluid—gas diagrams. We investigated the critical lines of polymer—solvent systems at the mathematical double point, where two critical lines meet and exchange branches, and its environment within the framework of a model that combines the lattice gas model of Schouten, ten Seldam and Trappeniers with the Flory—Huggins theory.
The critical lines are expressed as a function of x 1 and x 2 , the density of type 1 polymer molecules and the density of type 2 polymer molecules, respectively; in this way global phase diagrams are presented and discussed in the density—density plane.
Density—density plots are preferable when studying the differences in behavior of different classes, since they enable us to follow the connectivities in a systematic way. In this study the connectivity of critical lines at the mathematical double point and its around is investigated in detail. We also discuss the topology of the critical lines according to the Sadus classification scheme for ternary mixtures.
Critical lines; Gas—liquid systems; Global phase diagram; Polymer—solvent systems; Modified Tompa model;. Isothermal vapor—liquid equilibrium VLE of the following systems was measured with a recirculation still: Liquid and vapor phase compositions were determined with gas chromatography. All measured data sets passed the thermodynamic consistency tests.
The activity coefficients at infinite dilution are also presented. Methods for estimating solute solubilities in high temperature water both below and above its boiling point under pressure are needed for applications of this medium in processing applications such as sub-critical water extraction, reaction chemistry in heated water, and in the material sciences.
There is a paucity of data and correlative methods for estimating solute solubilities under these conditions; the limited existing methods are based on a limited solubility data base, and in some cases predicted solubility values are in quite serious disagreement with experimentally derived data. Here available solute solubility data both above and below the boiling point of water has been correlated for diverse solute types consisting of hydrocarbons, essential oil components, pesticides, polyphenolic compounds, as well as solutes exhibiting high solubility in water under the stated conditions.
Utilizing solubility data from diverse sources, appropriate conversions and equations have been derived for converting all solubility data to a mole fraction basis, while the other required physicochemical parameters, such as melting point, boiling point, critical properties, have been estimated, when necessary, largely by group contribution-based methods.
A solubility model based on such physicochemical parameters and critical properties of the solutes was derived. High temperature water; Solute solubility; Sub-critical water; Temperature effect;. New sorption and solvation measuring methods: Forced flow through liquids and solid state fluidised bed sorbents in high pressure gravimetry by Tobias Fieback; Frieder Dreisbach; Marcus Petermann; Roland Span; Eckard Weidner A novel measuring method is presented here that allows sorption and solvation measurements near to different process conditions.
Especially for the sorption kinetics it is important that the measuring conditions are similar to later applications. Particularly for high pressure sorption measurements this claim could not be fulfilled for most technical applications. The advantage of the measuring methods presented here is that solid bed samples in high pressure gravimetry can be measured under flow-through conditions in both directions and, for the first time in high pressure gravimetry, liquid samples can be measured under flow-through conditions.
Especially for ionic liquids, of which a large variety of new substances with unknown sorption potentials have been synthesised in the last few years, this results in much shorter measuring times. The first measurements presented here show that the new system allows for measuring times around 26 times shorter for an ionic liquid. Absorption; Carbon dioxide; Fluidised bed; Forced flow through; Gravimetry; Magnetic suspension balance; Solvation; Sorption measuring;.
Identification of the phase of a fluid using partial derivatives of pressure, volume, and temperature without reference to saturation properties: Applications in phase equilibria calculations by G. The phase of a fluid liquid, vapor at a given state is normally identified by comparing the properties of the fluid at the given state with saturation properties. In this paper we present a thermodynamic method for determining the phase of a fluid from the partial derivatives of pressure, volume and temperature without reference to saturated properties.
The method has immediate application in a variety of phase equilibria calculations, particularly for liquid—liquid or vapor—liquid—liquid equilibria calculations in process simulators. Phase identification; Multiphase equilibria; Process simulators;. Binary diffusion coefficients of phenolic compounds in subcritical water using a chromatographic peak broadening technique by Keerthi Srinivas; Jerry W. Infinite dilution diffusion coefficients of certain phenolic compounds were measured as a function of temperature in water slightly acidified with formic acid using the Taylor dispersion method.
The diffusion coefficients calculated using the chromatographic peak broadening technique were found to increase exponentially with an increase in the temperature. The diffusion coefficients of the selected phenolic compounds did not vary as a function of their molecular weights and the diffusion coefficients of the phenolic compounds increased as a function of temperature from 2.
The experimentally measured diffusion coefficients of the phenolic compounds were correlated as a function of temperature and solvent viscosity and were compared with those predicted using theoretical models.
The validity of the Stokes—Einstein diffusion model in predicting the diffusion coefficients of the phenolic compounds in hot pressurized water was also evaluated. Towards predictive association theories by Georgios M. Kontogeorgis; Ioannis Tsivintzelis; Michael L. In this work we focus on two of these models, the CPA and the NRHB equations of state and the emphasis is on the analysis of their predictive capabilities for a wide range of applications. We use the term predictive in two situations: Moreover, it is demonstrated that the NRHB equation of state is a versatile tool which can be employed equally well to mixtures with pharmaceuticals and solvents, including mixed solvents, as well as phase equilibria in mixtures containing glycols.
The importance of considering the solvation of CO 2 —water in CPA when the model is applied to multicomponent mixtures as well as of the multiple associations in heavy glycol—water mixtures in NRHB is investigated. Abraham; Pamela Twu; Jared L. The compiled partition coefficient data were analyzed using the ion-specific equation coefficient and the functional group contribution versions of the Abraham solvation parameter model. Ion-specific equation coefficients were calculated for 25 cations and 14 anions.
In addition, values were calculated for 14 cation functional groups and 14 anions. Room temperature ionic liquids; Linear free energy relationships; Activity coefficients; Group contribution methods; Gas chromatographic retention factors; Partition coefficients;.
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Chipkalorimetrie - Flash DSC | METTLER TOLEDO
construction of residual curves, fitting of recom. model parameters, methanol acetic acid methyl acetate water . Vapor Pressures. 15 Jun At room temperature and pressure, ortho- and meta-toluidines are viscous liquids , but para-toluidine is a flaky solid. 2-Methylaniline hydrochloride (the hydrochloride salt of o-toluidine) was Vapors are heavier than air. Areas under the plasma concentration-time curves (AUC) were determined. toring up to five component gases and water vapor in any air sample. . 1 atmosphere pressure and SIT=5 sec. .. Isobutyl acetate / 2-Methylpropyl acetate.