Showing papers in "Journal of Chemical & Engineering Data in 1997"

Surface Tension of Binary Mixtures of Water + Monoethanolamine and Water + 2-Amino-2-methyl-1-propanol and Tertiary Mixtures of These Amines with Water from 25 °C to 50 °C

Abstract: The surface tension of aqueous solutions of monoethanolamine, 2-amino-2-methyl-1-propanol, and monoethanolamine + 2-amino-2-methyl-1-propanol was measured at temperatures from 25 °C to 50 °C. The concentration ranges were 0−100 mass % monoethanolamine and 2-amino-2-methyl-1-propanol, and for tertiary mixtures 50 mass % total amine concentration (the concentration range for each amine was 0−50 mass %). The experimental values were correlated with temperature and mole fraction. The maximum deviation was in both cases always less than 0.5%.

Solubilities of the Fat-Soluble Vitamins A, D, E, and K in Supercritical Carbon Dioxide

Abstract: Solubilities of eight different species of the fat-soluble vitamins A, D, E, and K in supercritical carbon dioxide were measured at (313, 333, and 353) K and over a pressure range of 20 MPa to 35 MPa. Solubilities have been determined by an analytical method using the direct coupling of an equilibrium cell to a supercritical fluid chromatographic system with UV detection. The solubilities of all fat-soluble vitamins in supercritical carbon dioxide under the conditions investigated are in the range of 10 g/kg, except for β-carotene (provitamin A), which is 3 orders of magnitude less soluble. With increasing molecular mass of the vitamin, its solubility in supercritical carbon dioxide decreases. At constant temperature, the solubility of all substances increases with increasing density. At constant density, a rise of temperature results in an increase in solubility. This is caused by the increasing vapor pressure of the solid.

Heat Capacity of Aqueous Monoethanolamine, Diethanolamine, N-Methyldiethanolamine, and N-Methyldiethanolamine-Based Blends with Carbon Dioxide

Abstract: New data are reported on the heat capacity of CO2-loaded, aqueous solutions of monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), and aqueous MDEA-based blends with MEA and DEA.

Measurement of Activity Coefficients at Infinite Dilution Using Gas−Liquid Chromatography. 5. Results for N-Methylacetamide, N,N-Dimethylacetamide, N,N-Dibutylformamide, and Sulfolane as Stationary Phases

Abstract: Activity coefficients at infinite dilution are reported for more than 40 solutes (alkanes, alcohols, ketones, aromatic hydrocarbons, halocarbons, esters, nitriles, aldehydes, ethers, furan, pyridine, and water) in four selective solvents (N-methylacetamide, N,N-dimethylacetamide, N,N-dibutylformamide and sulfolane) at 303, 318, and 333 K. These values were measured with the help of gas−liquid chromatography (GLC) and show a good agreement when comparing them with various activity coefficients at infinite dilution taken from the literature. The temperature dependence found in the GLC experiments could be confirmed using excess enthalpy data. An important application of the present data can be seen in the selection of a suitable solvent for selective separation processes such as azeotropic and extractive distillation or extraction, where it is usually sufficient to know the ratio of the limiting activity coefficients of the components to be separated (selectivity at infinite dilution) in order to determine ...

Solubility of CO2 in Aqueous Methyldiethanolamine Solutions

Abstract: For 5.0, 20.5, 50.0, and 75.0 mass % methyldiethanolamine (MDEA) aqueous solutions, solubilities of CO2 were measured at 323.15, 348.15, and 373.15 K, respectively. Isothermal absorption capacities of CO2 as a function of MDEA concentration are presented. Lastly, the absorption enthalpy of CO2 in 50.0 mass % MDEA solution was calculated to be 54 kJ·mol-1 CO2.

Critical Evaluation of the Thermodynamic Properties of Aqueous Calcium Chloride. 1. Osmotic and Activity Coefficients of 0−10.77 mol·kg-1 Aqueous Calcium Chloride Solutions at 298.15 K and Correlation with Extended Pitzer Ion-Interaction Models

Abstract: Isopiestic vapor-pressure measurements were performed at 298.15 K for CaCl2(aq) solutions at 66 molalities from (4.3235 to 10.253) mol·kg-1, using H2SO4(aq) as the reference standard, with emphasis given to the accurate characterization of the osmotic coefficients near and above saturation. Published isopiestic molalities, direct vapor pressures, and emf results for CaCl2(aq) have been critically reevaluated and recalculated in an internally consistent manner. This critically-assessed database was used to evaluate the parameters of Pitzer's equations and various extended forms at 298.15 K and 0.1 MPa. Neither the standard equations nor empirically extended versions were able to represent the thermodynamic results over more than part of the molality range without large cyclic systematic deviations. It was possible, however, to obtain essentially quantitative agreement between experiment and model over the full molality range if (1) the presence of CaCl+(aq) ion pairs was included explicitly and (2) higher-...

Surface Tension of Organic Acids + Water Binary Mixtures from 20 °C to 50 °C

Abstract: The surface tensions of aqueous solutions of formic acid, acetic acid, and propionic acid were measured over the entire concentration range at temperatures (20 to 50) °C. The experimental values were correlated with temperature and mole fraction. Maximum deviations were in both cases always less than 1%.

Volumetric Properties of Carbon Dioxide + Acetone at High Pressures

Abstract: The volumetric properties of carbon dioxide + acetone mixtures have been determined at 323, 348, 373, 398, and 423 K at pressures up to 70 MPa using a variable-volume view cell. Densities for pure components and mixtures containing 90, 80, 70, and 50% by mass carbon dioxide are reported as a function of pressure at each temperature. It is shown that this system undergoes a density crossover at high pressures with each composition, a phenomenon previously reported also for mixtures of carbon dioxide + pentane and carbon dioxide + toluene. In the composition range investigated, the excess volume of the mixtures becomes more positive with increasing pressure but more negative with increasing temperature.

Solubility of Disperse Dyes in Supercritical Carbon Dioxide

Abstract: The solubilities of eight disperse dyes, suitable for dyeing from a supercritical medium, have been measured in supercritical carbon dioxide. For two of the dyes, 3-(1H-benzoimidazol-2-yl)-7-(diethylamino)chromen-2-one (C.I. Disperse Yellow 82, DY82) and 1-((4-aminophenyl)azo)-2-naphthol, studies have been made at 80 °C and 100 °C between 200 bar and 350 bar. The results were correlated using a semi-empirical equation. The remaining six dyes were studied at 200 bar and 80 °C, to investigate trends of solubility with molecular properties.

Temperature and Concentration Dependence of the Specific Conductivity of Concentrated Solutions of Potassium Hydroxide

Abstract: The specific conductivity of concentrated solutions of potassium hydroxide was measured over a temperature range of −15 to 100 °C for concentrations of 15 to 45 mass %. An empirical correlation relating temperature, mass % KOH, and specific conductivity was made with a correlation coefficient of 0.9995. Using experimental density data from Akerlof and Bender, the correlation was extended to relate temperature, molarity, and conductivity.

Speeds of sound and viscosities in aqueous poly(ethylene glycol) solutions at 303.15 and 308.15 K

Abstract: Speeds of sound (u) and viscosities (η) of water + glycol (mono-, di-, tri-, and tetraethylene glycol) mixtures have been measured at 303.15 K and 308.15 K. The results have been combined with those of our previous results for excess molar volumes converted to densities to obtain isentropic compressibilities. From the experimental data deviations in isentropic compressibility and viscosity have been calculated over the entire composition range.

Equilibrium Phase Behavior of Poly(ethylene glycol) + Potassium Phosphate + Water Two-Phase Systems at Various pH and Temperatures

Abstract: This work presents the effects of changes in temperature (4 °C, 25 °C, and 40 °C), pH (6, 7, and 9), and polymer molecular weight (1000 and 8000) on the equilibrium phase behavior of two-phase PEG + potassium phosphate + water systems. As the temperature and pH were increased, the binodal curve shifted to lower polyethylene and phosphate concentrations, resulting in a higher difference in polymer and salt concentrations between the top and bottom phases. This corresponds to an increase in the region of two-phase coexistence.

Thermodynamic Properties and Ideal-Gas Enthalpies of Formation for Dicyclohexyl Sulfide, Diethylenetriamine, Di-n-octyl Sulfide, Dimethyl Carbonate, Piperazine, Hexachloroprop-1-ene, Tetrakis(dimethylamino)ethylene, N,N‘-Bis-(2-hydroxyethyl)ethylenediamine, and 1,2,4-Triazolo[1,5-a]pyrimidine

Abstract: This paper reports measurements made for DIPPR Research Project 871 in the 1993 Project Year. The results of the study are aimed at improvement of group-contribution methodology for estimation of thermodynamic properties of organic substances. Specific weaknesses where particular group-contribution terms were unknown, or estimated because of lack of experimental data, are addressed by experimental studies of enthalpies of combustion in the condensed phase, vapor-pressure measurements, and differential scanning calorimetric (DSC) heat-capacity measurements. Ideal-gas enthalpies of formation of hexachloroprop-1-ene, N,N‘-bis(2-hydroxyethyl)ethylenediamine, dimethyl carbonate, di-n-octyl sulfide, dicyclohexyl sulfide, diethylenetriamine, tetrakis(dimethylamino)ethylene, piperazine, and 1,2,4-triazolo[1,5-a]pyrimidine are reported. Enthalpies of fusion were determined for N,N‘-bis(2-hydroxyethyl)ethylenediamine, piperazine and 1,2,4-triazolo[1,5-a]pyrimidine. Two-phase (solid + vapor) or (liquid + vapor) heat...

Vapor pressure, heat capacity, and density along the saturation line, measurements for cyclohexanol, 2-cyclohexen-1-one, 1,2-dichloropropane, 1,4-di-tert-butylbenzene, ({+-})-2-ethylhexanoic acid, 2-(methylamino)ethanol, perfluoro-n-heptane, and sulfolane

Abstract: This paper reports measurements made for DIPPR Research Project 821 in the 1994 Project Year. Vapor pressures were measured to a pressure limit of 270 kPa or lower decomposition point for eight compounds using a twin ebulliometric apparatus. Liquid-phase densities along the saturation line were measured for each compound over a range of temperatures (ambient to a maximum of 548 K). A differential scanning calorimeter (DSC) was used to measure two-phase (liquid + vapor) heat capacities for each compound in the temperature region ambient to the critical temperature or lower decomposition point. Where possible, the critical temperature and critical density for each compound were determined experimentally. The results of the measurements were combined to derive a series of thermophysical properties including critical temperature, critical density, critical pressure, acentric factor, enthalpies of vaporization [within the temperature range (±50 K) of the vapor pressures], enthalpies of fusion if solid at ambie...

Density, Refractive Index, Viscosity, and Speed of Sound in Binary Mixtures of Ethenylbenzene with Hexane, Heptane, Octane, Nonane, Decane, and Dodecane

Abstract: Experimental densities, refractive indices, and viscosities at 298.15, 303.15, and 308.15 K and speeds of sound values at 298.15 K are presented for the binary mixtures of ethenylbenzene with hexane, heptane, octane, nonane, decane, and dodecane over the entire compositions. From these data, excess molar volumes, deviations in refractive index, speed of sound, and viscosity have been computed. These parameters have been fitted to the Redlich−Kister equation using a multiparametric nonlinear regression analysis. Estimated coefficients and standard error values for the mixing quantities are presented for each of the binary mixtures. Experimental and computed results are discussed in terms of molecular interactions.

Densities of Aqueous Blended Amines

Abstract: The densities of aqueous mixtures of diethanolamine (DEA) + N-methyldiethanolamine (MDEA) + water, DEA + 2-amino-2-methyl-1-propanol (AMP) + water, and monoethanolamine (MEA) + 2-piperidineethanol (2-PE) + water were measured from 30 °C to 80 °C. A Redlich−Kister equation of the excess volume was applied to represent the density. Based on the available density data for five ternary systems: MEA + MDEA + H2O, MEA + AMP + H2O, DEA + MDEA + H2O, DEA + AMP + H2O, and MEA + 2-PE + H2O, a generalized set of binary parameters were determined. The density calculations show quite satisfactory results. The overall average absolute percent deviation is about 0.04% for a total of 686 data points.

Viscosity and Density of H2O + NaCl + CaCl2 and H2O + KCl + CaCl2 at 298.15 K

Abstract: The viscosity and density of water + sodium chloride + calcium chloride solutions and water + potassium chloride + calcium chloride solutions were measured over the entire concentration range at 298.15 K. The recently extended Jones−Dole equation still functions well for these systems up to a high concentration. It has been empirically found that when a seventh term of molarity was further added to the extended Jones−Dole equation, the viscosity for calcium chloride solutions and the mixed electrolyte solutions with larger ionic strengths could be excellently represented up to their saturated concentrations. In consideration of the large solubility of calcium chloride and furthermore of its large ionic strength and of its large viscosity−concentration coefficient, it could be supposed that the extented Jones−Dole equation in this work should fit many aqueous electrolyte solutions to their rather high concentrations or just to the saturated concentrations. In low concentrations, the calculated viscosity va...

Compressed and Saturated Liquid Densities for 18 Halogenated Organic Compounds

Abstract: The pressure−density−temperature P(ρ,T) behavior of 18 liquids that are potential working fluids in thermal machinery has been measured using a vibrating tube densimeter. For each liquid, the data were taken on isotherms spaced at intervals of 5 K to 10 K spanning the temperature range 245 K to 370 K. The pressures ranged from just above the vapor pressure (or the critical pressure) to 6500 kPa. The results of measurements at more than 12 000 thermodynamic points are summarized by correlating functions. Comparison with data from other laboratories indicates that the relative expanded uncertainty in the measured densities is less than 0.05%, except in the critical region. The repeatability of the measured densities is on the order of 0.005%. For each liquid, the P(ρ,T) data were extrapolated to the vapor pressure to obtain the density of the liquid at the vapor pressure. The fluids studied (and their designations by the refrigeration industry) were trichlorofluoromethane (R11), chlorodifluoromethane (R22),...

Liquid−Liquid Equilibria of the Ternary System Water + Acetic Acid + 1-Hexanol

Abstract: Liquid−liquid equilibria for the ternary system water + acetic acid + 1-hexanol were measured over a temperature range of (288 to 323) K. The results were used to estimate the interaction parameters between each of the three compounds for the NRTL and UNIQUAC models and between each of the main groups of H2O, CH2 (paraffinic CH2), OH, and COOH for the UNIFAC model as a function of temperature. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the three models. The NRTL equation was the most accurate model in correlating the overall equilibrium compositions of the studied system. The UNIQUAC and UNIFAC models satisfactorily predicted the equilibrium compositions.

Solubility of carbon dioxide in acetone and propionic acid at temperatures between 298 K and 333 K

Abstract: The solubility of carbon dioxide in organic solvents acetone and propionic acid has been measured with an analytical method. The composition and the density of the liquid phase in the binary vapor−liquid equilibrium have been investigated at (313 and 333) K (for the system carbon dioxide + acetone) and at (298, 313, and 333) K (for the system carbon dioxide + propionic acid) at pressures up the binary critical pressure. The experimental results for the phase equilibrium have been correlated with the Peng−Robinson EOS applying several mixing rules.

Thermal conductivities of some organic solvents and their binary mixtures

Abstract: The thermal conductivity of 12 pure organic solvents, acetone, acetonitrile, acrylonitrile, carbon tetrachloride, chloroform, 1,2-dichloroethane, ethanol, ethyl acetate, heptane, tetrahydrofuran, toluene, and water, and eight binary mixtures, acetone + ethanol, acetone + ethyl acetate, ethanol + heptane, ethanol + carbon tetrachloride, ethyl acetate + ethanol, heptane + acetone, heptane + toluene, and water + ethanol, were measured by an absolute transient hot-wire method at some selected temperatures from 253.15 K to 303.15 K. A correlation previously developed was used to calculate the thermal conductivity. The agreement between the experimental and the calculated thermal conductivities is satisfactory.

Vapor Pressure, Heat Capacity, and Density along the Saturation Line, Measurements for Dimethyl Isophthalate, Dimethyl Carbonate, 1,3,5-Triethylbenzene, Pentafluorophenol, 4-tert-Butylcatechol, α-Methylstyrene, and N,N‘-Bis(2-hydroxyethyl)ethylenediamine

Abstract: This paper reports measurements made for DIPPR Research Project 821 in the 1993 Project Year. Vapor pressures were measured to a pressure limit of 270 kPa or lower decomposition point for all seven compounds using a twin ebulliometric system and, for dimethyl isophthalate and N,N‘-bis(2-hydroxyethyl)ethylenediamine, additionally an inclined-piston apparatus. Liquid-phase densities along the saturation line were measured for each compound over a range of temperature (ambient to a maximum of 548 K). A differential scanning calorimeter (DSC) was used to measure two-phase (liquid + vapor) heat capacities for each compound in the temperature region ambient to the critical temperature or lower decomposition point. Where possible, the critical temperature and critical density for each compound were determined experimentally. The results of the measurements were combined to derive a series of thermophysical properties including critical temperature, critical density, critical pressure, acentric factor, enthalpies...

Temperature and Density Dependence of the Viscosity of Octane and Toluene

Abstract: Fluids of larger polyatomic molecules do not well fit the hard sphere model of dense fluids as their liquid range, reduced in terms of relative molecular volumes, usually extends well beyond the freezing density of the hard sphere fluid. Even where overlap occurs, the density dependence is observed to be not as simple as that of the model. It is for this reason that empirical functions for the density dependence of the transport properties have been developed. Application of such correlations has thrown some doubt on previous high-pressure measurements of the viscosity of liquid octane and toluene. New measurements have been made for octane between 283 K and 348 K and for toluene at 298 K and 323 K at pressures up to approximately 375 MPa with a falling-body viscometer. These are supplemented by pVT measurements for octane between 278 K and 298 K, which have been used to improve an earlier equation of state. The viscosity results are compared with earlier data using a general correlation method for molecu...

Isothermal Vapor−Liquid Equilibria Measurements, Excess Molar Enthalpies, and Excess Molar Volumes of Dimethyl Carbonate + Methanol, + Ethanol, and + Propan-1-ol at 313.15 K

Abstract: Isothermal vapor−liquid equilibria (VLE), excess molar enthalpies, , and excess molar volumes, , have been measured for the binary mixtures dimethyl carbonate + methanol, + ethanol, or + propan-1-ol at 313.15 K and at atmospheric pressure. The three mixtures exhibit large deviations from ideality, showing an azeotrope at 0.14, 0.42, and 0.78 mole fraction of dimethyl carbonate, respectively. The VLE data were correlated by the Wilson equation and the appropriate parameters are reported. and values have been correlated using the Redlich−Kister equation by the method of least-squares.

Effect of dissolved gases on the densities of hydrocarbons

Abstract: Measurements have been made, using a vibrating tube densitometer, of the effects of dissolved air, nitrogen, oxygen, hydrogen, methane, and carbon dioxide on the densities of liquid hydrocarbons at 298.15 K and a total pressure of 101 060 Pa. The hydrocarbons were heptane, octane, nonane, decane, dodecane, tetradecane, hexadecane, cyclohexane, methylcyclohexane, and methylbenzene (toluene). Saturation of the liquids with gases other than carbon dioxide decreases the density by amounts ranging from about 0.004% for oxygen in hexadecane up to about 0.1% for methane in heptane. Saturation with carbon dioxide increases the densities by a maximum of almost 0.1%. For all gases, values of |Δρ| decrease with increasing carbon number in an approximately linear manner in the alkane series. Partial molar volumes of the gaseous solutes have been calculated by combining the density results with literature gas solubility data.

Thermodynamic Behavior of Mixtures. 4. Mixtures of Methanol with Pyridine and N,N-Dimethylformamide at 25 °C

Abstract: Ultrasonic velocities (u), densities (ρ), viscosities (η), relative permittivities (er), and refractive indices (nD) of mixtures of methanol (MeOH) with pyridine and N,N-dimethylformamide (DMF) have been measured at 25 °C. From u, ρ, and η, deviation in isentropic compressibilities ( ), excess volumes (VE), and viscosities (Δη) have been computed. From nD and er values, the Kirkwood correlation factor, g, has been evaluated. The variation of such properties shows specific interactions between the components of MeOH + pyridine and MeOH + DMF binary mixtures.

Excess Molar Volumes and Excess Molar Heat Capacities of Mixtures Containing (Mono and Poly)ethers + Ethyl Acetate

Abstract: Excess molar volumes were obtained from density measurements for binary mixtures of ethyl acetate [CH3COOCH2CH3] with glymes [CH3O(CH2CH2O)nCH3, n = 1, 2, 3, and 4] and dibutyl ether [(CH3CH2CH2CH2)2O] at (278.15, 288.15, 298.15, and 308.15) K and atmospheric pressure using a Kyoto Electronics DA-210 vibrating-tube densimeter. In addition, excess molar isobaric heat capacities were determined for ethyl acetate with glymes (n = 2, 4) and dibutyl ether at 298.15 K using a micro DSC II differential scanning calorimeter.

Excess molar enthalpies of (water + alkanolamine) systems and some thermodynamic calculations

Abstract: Several (water + alkanolamine) systems are used for removal of acidic gases such as carbon dioxide and hydrogen sulfide from gas streams in the natural gas and petroleum industries and are of increasing importance in treating streams in the chemical production industries. The authors have made calorimetric measurements of enthalpies of mixing of (water + monoethanolamine), (water + diethanolamine), and (water + triethanolamine) at T = 298.15 K and of (water + methyldiethanolamine) at T = 298.15 and 313.15 K. Results of these measurements have been used in some thermodynamic calculations to illustrate general principals that are applicable to many systems of mixed liquids.

Temperature Dependence of Octanol−Water Partition Coefficient for Selected Chlorobenzenes

Abstract: The octanol−water partition coefficients of seven chlorobenzenes (1,2-dichlorobenzene, 1,4-dichlorobenzene, 1,3,5-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, 1,2,3,5-tetrachlorobenzene, pentachlorobenzene, and hexachlorobenzene) were measured by a conventional shake-flask, batch-contacting method over the temperature range (5 to 45) °C. The measurements at 25 °C in this study agree well with literature data obtained with comparable methods. The van't Hoff plots of log KOW versus T-1 exhibit linearity with values of KOW increasing by 10%−14% over this temperature range. The enthalpy of phase change ranges from (17 to 24) kJ/mol. These temperature relationships can be incorporated into environmental models which predict the fate of chemicals in aquatic and terrestrial systems over a range of environmental temperatures.

Density and Viscosity for Monoethanolamine + 1-Propanol, + 1-Hexanol, and + 1-Octanol

Abstract: Densities and viscosities were measured for monoethanolamine (MEA) + 1-propanol, MEA + 1-hexanol, and MEA + 1-octanol at 303.15 K, 313.15 K, and 323.15 K. The excess volumes and viscosity deviations from the mole fraction average were calculated and correlated by a Redlich−Kister type equation. McAllister’s three-body interaction model was also applied to correlate the kinematic viscosities.