Prediction of Ternary Liquid Adsorption on Solids from Binary Data

The adsorption behavior of the ternary n-hexane/n-octane/n-tetradecane mixture and the binary n-hexane/n-octane, n-octane/n-tetradecane, n-hexane/n-tetradecane mixtures on the well-characterized TA 95 activated carbon has been studied. Measured binary data at 25 degrees C are used to predict the ternary data which are compared with measured ones. With the measured binary data at 15 degrees C, a prediction of ternary data is proposed without ternary experimental support. To predict ternary data from the binary ones, a thermodynamical model combining the methods of Myers and Price and Danner is used. Copyright 2000 Academic Press.     

Adsorption of the Ternary Liquid Mixture Ethanol/n-Octane/n-Hexadecane onto Activated Carbon: I. The Adsorption Excess of the Ternary Mixture and of Its Binary Combinations

The adsorption isotherms of the binary mixtures of ethanol/n-Octane, ethanol/n-hexadecane and n-octane/n-hexadecane onto the activated carbon TA 95 were measured at 278 K, 288 K, 298 K and 308 K and described with mathematical functions. About 300 experimental values of the adsorption excess of the ternary mixture ethanol/n-octane/n-hexadecane onto activated carbon TA 95 at 298 K were measured by gas chromatography inside the ternary triangle. The ternary miscibility gap was determined at three temperatures. A good representation of the ternary data and the calculated activity coefficients (using the UNIFAC model) in three-dimensional space was possible with the help of transformation of coordinates. It was possible, too, by utilization of the conception of the quasi two-component representation of the mole fractions with and without miscibility gap. Several influencing factors on ternary adsorption isotherms were discussed for the system ethanol/n-octane/n-hexadecane/TA 95.     

正丁醇、乙酸乙酯、正己烷的二元及三元体系的超额焓测量和关联

用等温稀释量热计测定了正己烷+正丁醇、正己烷+乙酸乙酯二元体系在303.15K、308.15K及正丁醇+乙酸乙酯+正己烷三元体系在303.15K的超额焓,用Kretschrner-Wiebe理论组合UNIQUAC方程所得数学模型对二元体系在303.15K的超颠焓进行了关联,并预测了所测三元体系在303.15K的超额焓,预测结果与实验值比较,平均偏差为6％。     

Volumes and viscosities of benzene + n-alkane mixtures

Excess molar volumes, viscosities, excess molar viscosities and excess molar activation energies of viscous flow were determined for binary mixtures of benzene + n-hexane, + n-octane, + n-decane, + n-dodecane, + n-tetradecane and + n-hexadecane at 298.15 K. The effect of orientational order of n-alkane on solution molar volumes and viscosities is investigated as well as the adequacy of the absolute rate and free volume theories to predict solution viscosities. For longer n-alkane ΔG*^E and Δ 1n η are positive and associated with the orientational order.     

Prediction of multicomponent liquid adsorption using excess quantities. III. Calculations for the liquid/air interface

The utilization of excess quantities as the basis of a thermodynamic approach can simplify the prediction of multicomponent data from binary ones. Whereas in Part II the excess formalism was applied to the prediction of liquid phase adsorption on solids, in this paper, the liquid/air interface is investigated. In order to show the generality of the suggested approach, thermodynamic equations are developed in analogy to Part II. Surface tensions are predicted by different excess models and compared with experimental data. From predicted surface tensions, ternary adsorption isotherms on the liquid/air interface are calculated.     

Application of Different Group Contribution Models and Empirical Methods to Excess Enthalpies of Ternary Mixtures

Studies were previously made of the excess molar enthalpies, H_m ^E, at 298.15 K and normal atmospheric pressure of the ternary mixtures (ethyl propanoate or 3-pentanone) + (n-hexane) + (n-decane, n-dodecane or n-tetradecane) and (1-propanol) + (3-pentanone) + (n-hexane, n-heptane, n-octane, 1-hexanol or 1-heptanol). In the present work, experimental values of H_m ^E were correlated through use of the Cibulka and Nagata equations, and a new correlation equation is proposed. Experimental data were compared with the predictions of the UNIFAC I (version of Tassios), UNIFAC II (version of Larsen) and Nitta-Chao group contribution models. H_m ^E values were used to test several empirical predictive methods, both symmetric (Kohler, Jacob-Fitzner, Colinet and Knobeloch-Schwartz), and asymmetric (Tsao-Smith, Toop, Scatchard, Hillert and Mathieson-Tynne). This revised version was published online in July 2006 with corrections to the Cover Date.     

预测三元系超额焓的一种新方法

提出一种预测三元系超额焓的新方法。该方法利用改进的立方状态方程－－ＦＲＫＳ方程，并以二元互作用参数函数代替单一数值的二地互作用参数，为计算体系提供随状态变化的二元互作用参数数值。对十二个非理想三元系及其组分二元素的计算结果表明，该方法明显提高了二元系超额焓的拟合精度，从而在不引入任何三元参数的条件下较好地改进了三元系超额焓的预测。     

Correlation between excess adsorption data measured for solvent mixture/adsorbent systems and RM values obtained for different solutes chromatographed in binary mobile phases

This paper concerns the application of excess adsorption isotherms, measured for solvent mixture/adsorbent systems, to the characterization of TLC data. For this purpose the excess adsorption isotherms for three liquid mixtures: cyclohexane/ benzene, benzene/acetone, and carbon tetrachloride/ethyl acetate on silica gel at 20°C have been measured. These mixtures have been used as binary mobile phases in TLC measurements. It has been shown for a given solute in binary mobile phase that the quantity R_M is a simple function of the excess adsorption. Parameters of this function have been used to characterize chromatographic systems with binary mobile phases.     

Modeling high-pressure adsorption of gas mixtures on activated carbon and coal using a simplified local-density model

The simplified local-density (SLD) theory was investigated regarding its ability to provide accurate representations and predictions of high-pressure supercritical adsorption isotherms encountered in coalbed methane (CBM) recovery and CO2 sequestration. Attention was focused on the ability of the SLD theory to predict mixed-gas adsorption solely on the basis of information from pure gas isotherms using a modified Peng-Robinson (PR) equation of state (EOS). An extensive set of high-pressure adsorption measurements was used in this evaluation. These measurements included pure and binary mixture adsorption measurements for several gas compositions up to 14 MPa for Calgon F-400 activated carbon and three water-moistened coals. Also included were ternary measurements for the activated carbon and one coal. For the adsorption of methane, nitrogen, and CO2 on dry activated carbon, the SLD-PR can predict the component mixture adsorption within about 2.2 times the experimental uncertainty on average solely on the basis of pure-component adsorption isotherms. For the adsorption of methane, nitrogen, and CO2 on two of the three wet coals, the SLD-PR model can predict the component adsorption within the experimental uncertainties on average for all feed fractions (nominally molar compositions of 20/80, 40/60, 60/40, and 80/20) of the three binary gas mixture combinations, although predictions for some specific feed fractions are outside of their experimental uncertainties.     

Immersion enthalpy and the constants of Langmuir model in the 3-chloro phenol adsorption on activated carbon

The adsorption process of 3-chloro phenol from aqueous solution on a activated carbon prepared from African palm stone and which presents a specific surface area of 685 m² g⁻¹, a greater quantity of total acid groups and a pH_PZC of 6.8 is studied. The adsorption isotherms are determined at pH values of 3, 5, 7, 9 and 11. The adsorption isotherms are fitted to the Langmuir model and the values of the maximum quantity adsorbed that are between 96.2 and 46.4 mg g⁻¹ are obtained along with the constant K_L with values between 0.422 and 0.965 L mg⁻¹. The maximum quantity adsorbed diminishes with the pH and the maximum value for this is a pH of 5. The immersion enthalpies of the activated carbon in a 3-chloro phenol solution of constant concentration, of 100 mg L⁻¹, are determined for the different pH levels, with results between 37.6 and 21.2 J g⁻¹. Immersion enthalpies of the activated carbon in function of 3-chloro phenol solution concentration are determined to pH 5, of maximum adsorption, with values between 28.3 and 38.4 J g⁻¹, and by means of linearization, the maximum immersion enthalpy is calculated, with a value of 41.67 J g⁻¹. With the results of the immersion enthalpy, maximum quantity adsorbed and the constant K_L, establish relations that describe the adsorption process of 3-chloro phenol from aqueous solution on activated carbon.     

Excess Molar Volumes of (Methyl Ethanoate + 1-Chlorooctane + an n-Alkane) Ternary Mixtures and Their Constituent Binaries at 25°C

Excess molar volumes, at the temperature 25°C and atmospheric pressure over the whole composition range, are reported for the following binary mixtures: methyl ethanoate + (n-octane, n-decane); methyl ethanoate + 1-chlorooctane; 1-chlorooctane + (n-heptane, n-octane, n-nonane, n-decane); and for the ternary mixtures methyl ethanoate + 1-chlorooctane + (n-heptane, n-octane, n-nonane, n-decane). The values of excess molar volumes were calculated from density and composition results. The excess volumes were utilized to test the multiproperty group-contribution model of Nitta et al. using parameter sets available in the literature. Experimental results from ternary mixtures have also been compared to predictions from several empirical and semiempirical models, which utilize, exclusively, results from binary mixtures.     

Liquid-liquid equilibria for the acetonitrile + methanol + saturated hydrocarbon and acetonitrile + 1-butanol + saturated hydrocarbon systems

Tie-line results at 25°C and atmospheric pressure are presented for {(acetonitrile + methanol) + cyclohexane, or + n-hexane, or + n-heptane or + n-octane} and for {(acetonitrile + 1-butanol) + cyclohexane, or + n-hexane or + n-heptane}. Vapor-liquid equilibria for acetonitrile + methanol at 25° C are reported. The UNIQUAC associated-solution model is used to correlate binary vapor-liquid equilibria and mutual solubilities for the 13 systems constituting the ternary systems and to predict the ternary liquid-liquid equilibria by using binary parameters alone.     

Molar excess volumes of binary mixtures of ethylbenzene with n-alkanes at 298.15 k; an interpretation in terms of the prigogine-flory-patterson model

Molar excess volumes are reported for binary mixtures of ethylbenzene with n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-dodecane, n-tetradecane and n-hexadecane at 298.15 K and over the whole mole fraction range. The Prigogine-Flory-Patterson model of solution thermodynamics has been used to predict the molar excess volumes. The values of V^E_m are well predicted and the results show the importance of the three contributions, ΔV_inter, Δ_p and ΔV_F, to V_m^E.     

高比表面活性碳微球分离H2中少量CO2

以实验数据为依据, 结合双Langmuir模型研究了用高比表面活性碳微球材料分离H2中少量CO2的行为. 在实验中, 用高精度的IGA-003重力吸附仪测定了温度为298、273 和268 K, 压力在0-1.8 MPa范围内CO2、H2及n(CO2):n(H2)=1:9混合物在活性碳微球中的吸附等温线. 比较不同吸附模型的计算结果与实验数据, 结果表明, 双Langmuir模型与实验结果拟合得较好; 而且通过结合理想吸附溶液理论, 该模型可以准确地计算不同的混合物体系(包括H2-CO2体系)的吸附量和吸附选择性. 利用该模型求解了不同温度下各组分的分吸附量, 得到了CO2的吸附选择性;在268 K和1.7 MPa下, CO2的吸附选择性可达到73.4, 表明活性碳微球是一种优秀的吸附H2中少量CO2的材料.     

Activated Carbon Adsorption of Some Phenolic Compounds Present in Agroindustrial Wastewater

Single solute and simultaneous experimental adsorption isotherms of three phenolic compounds: gallic acid, p-hydroxybenzoic acid and syringic acid, have been investigated at 20, 30 and 40°C, using a bituminous coal based activated carbon. Regardless of temperature, the capacity of the activated carbon used to adsorb these compounds presented the following order: syringic acid > p-hydroxybenzoic acid > gallic acid. The increase of temperature slightly favored the adsorption capacity of the phenolic compounds. In binary and ternary component adsorption, experimental data suggest that interactions between adsorbates improve the adsorption capacity of some of the phenolic acid compounds. On the contrary, at high organic concentrations, adsorbed gallic acid was partially removed from the activated carbon surface because of the presence of the other components.     

Boiling temperatures and excess thermodynamic functions of 2-propanol-n-alkyl propanoate solutions

Boiling temperatures of five binary systems are measured by ebuliometer in the pressure range of 5.333?C101.3 kPa. The compositions of equilibrium vapor phases in the systems are calculated using the constructed saturated vapor pressure isotherms as a base. The excess Gibbs energies, excess enthalpies, and excess entropies of solutions are calculated from our data on liquid-vapor equilibria. Regularities in the changes of phase equilibria and thermodynamic properties of solutions with the composition and temperature of the system are established. Vapor-liquid equilibria in the systems are described by the Wilson and NRTL equations.     

Excess thermodynamics properties of propyl propanoate+hexane+cyclohexane at 298.15 K

Summary In this paper we present excess molar volumes and excess molar enthalpies of binary and ternary mixtures containing propyl propanoate, hexane and cyclohexane as components at 298.15 K. Excess molar volumes were calculated from the density of the pure liquids and mixtures. The density was measured using an Anton Paar DMA 60/602 vibrating-tube densimeter. Excess molar enthalpies were obtained using a Calvet microcalorimeter     

Excess molar enthalpies of the ternary mixtures: (diisopropyl ether or 2-methyltetrahydrofuran) + cyclohexane + n-heptane at 298.15 K

Microcalorimetric measurements of excess molar enthalpies, at 298.15 K, are reported for the two ternary systems formed by mixing either diisopropyl ether or 2-methyltetrahydrofuran with binary mixtures of cyclohexane and n-heptane. Smooth representations of the results are presented and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. It is shown that useful estimates of the ternary enthalpies can be obtained from the Liebermann and Fried model, using only the physical properties of the components and their binary mixtures.     

Excess molar enthalpies of the ternary mixtures: (diisopropyl ether or tetrahydrofuran)+3-methylpentane+n-dodecane at 298.15 K

Microcalorimetric measurements of excess molar enthalpies, at 298.15 K, are reported for the two ternary systems formed by mixing either diisopropyl ether or tetrahydrofuran with binary mixtures of 3-methylpentane and n-dodecane. Smooth representations of the results are presented and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. It is shown that useful estimates of the ternary enthalpies can be obtained from the Liebermann and Fried model, using only the physical properties of the components and their binary mixtures.