Vapour-liquid equilibrium at low pressures from the back equation of state. II. Ternary systems

1984 ◽  
Vol 49 (5) ◽  
pp. 1240-1246
Author(s):  
Tomáš Boublík
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Ternary Systems ◽  
Liquid Equilibrium ◽  
Pure Compounds ◽  
Benzene Toluene ◽  
Excess Thermodynamic Functions ◽  
Low Pressures

Ternary equilibrium diagrams in the n-hexane-cyclohexane-benzene system at temperature 298.15 K and n-hexane-benzene-toluene system at pressure 101.325 kPa were determined from the BACK equation of state. In the course of the determination of excess thermodynamic functions of mixtures the values of the BACK equation parameters for pure compounds and binary interactions parameters, ki,j, adjusted to GE and HE of the corresponding binaries were employed. The comparison of theoretical and experimental data shows very good quality of the prediction of the equilibrium behaviour of polycomponent systems from the BACK equation of state.

Vapour-liquid equilibrium at low pressures from the back equation of state

1983 ◽  
Vol 48 (10) ◽  
pp. 2713-2720 ◽  
Author(s):  
Tomáš Boublík
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Binary Mixtures ◽  
Thermodynamic Functions ◽  
Mixing Rules ◽  
Liquid Equilibrium ◽  
Semiempirical Equation ◽  
Equilibrium Data ◽  
Excess Thermodynamic Functions ◽  
Low Pressures

The BACK semiempirical equation of state was employed to determine the excess thermodynamic functions of five binary mixtures composed of benzene with cyclohexane, n-pentane, n-hexane, n-heptane, and n-octane at 298.15 K. Two sets of mixing rules are discussed and values of the excess thermodynamic functions of equimolar solutions, calculated on their basis, are compared with experimental data. The calculated and experimental equilibrium data are compared in the x-y diagrams.

Excess entropy of the systems of molecules differing in size and shape

1983 ◽  
Vol 48 (1) ◽  
pp. 192-198 ◽  
Author(s):  
Tomáš Boublík
Keyword(s):  
Equation Of State ◽  
Hard Spheres ◽  
Excess Entropy ◽  
Convex Bodies ◽  
Pure Substance ◽  
Liquid Equilibrium ◽  
Simple Rules ◽  
Different Shapes ◽  
The Mean

The excess entropy of mixing of mixtures of hard spheres and spherocylinders is determined from an equation of state of hard convex bodies. The obtained dependence of excess entropy on composition was used to find the accuracy of determining ΔSE from relations employed for the correlation and prediction of vapour-liquid equilibrium. Simple rules were proposed for establishing the mean parameter of nonsphericity for mixtures of hard bodies of different shapes allowing to describe the P-V-T behaviour of solutions in terms of the equation of state fo pure substance. The determination of ΔSE by means of these rules is discussed.

Parameters of the Bender Equation of State for Chloro Derivatives of Methane and Chlorobenzene

2001 ◽  
Vol 66 (6) ◽  
pp. 833-854 ◽  
Author(s):  
Ivan Cibulka ◽  
Lubomír Hnědkovský ◽  
Květoslav Růžička
Keyword(s):  
Experimental Data ◽  
Equation Of State ◽  
Virial Coefficient ◽  
Second Virial Coefficient ◽  
Virial Coefficients ◽  
Liquid Equilibrium ◽  
Second Virial Coefficients ◽  
Equilibrium Data ◽  
State Behaviour ◽  
Derivatives Of

Values of adjustable parameters of the Bender equation of state evaluated for chloromethane, dichloromethane, trichloromethane, tetrachloromethane, and chlorobenzene from published experimental data are presented. Experimental data employed in the evaluation included the data on state behaviour (p-ρ-T) of fluid phases, vapour-liquid equilibrium data (saturated vapour pressures and orthobaric densities), second virial coefficients, and the coordinates of the gas-liquid critical point. The description of second virial coefficient by the equation of state is examined.

Solid-Liquid Equilibrium of Xylose in Water and Ethanol/Water Mixture

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Ernesto A Martínez ◽  
Marco Giulietti ◽  
Mauricio Uematsu ◽  
Silas Derenzo ◽  
João B Almeida e Silva
Keyword(s):  
Experimental Data ◽  
Prediction Models ◽  
Ternary Systems ◽  
The Other ◽  
Water Mixture ◽  
Liquid Equilibrium ◽  
Average Deviation ◽  
Vapor Liquid Equilibrium ◽  
Solid Liquid ◽  
Vapor Liquid

This work deals with the study of thermodynamical models for the solid-liquid equilibrium (SLE) and comparing its performance with experimental data. The xylose solubility in the xylose-water and xylose-water-ethanol systems has been measured using a variant of the isothermal method. A total of 12 experiments were performed in a 100 mL glass jacketed crystallizer with helix-type agitator by changing the temperature from 0 to 60°C. The solution was mixed during 72 h with an IKA Labortechnic, RW 20.n agitator at 450 rpm. Later, the experimental and reported results were fitted using the prediction models based on the vapor-liquid-equilibrium (UNIFAC (Universal Functional Activity Coefficient), ASOG (Analytical Solutions of Groups) and GSP (Group Solubility Parameter); semi-empirical models based on the vapor-liquid-equilibrium (VLE) (UNIQUAC (Universal Quasi Chemical), Wilson and NRTL (Non Randon Two Liquid)) on the solid-liquid-equilibrium, and empirical model with fitted parameters (Nývlt, λh, Margules with 1 and 2 parameters). The results showed that the UNIQUAC model with fitted parameters can describe the SLE with reasonable accuracy (1.28 and 3.36% for binary and ternary systems, respectively). The average deviation was the arithmetic mean of the deviations. On the other hand, the other methods resulted in poor agreement with the system’s behavior presenting systematic deviations from the experimental data.

A modification of the Redlich-Kwong-Soave equation of state and the determination of its parameters on the basis of saturated vapour pressures and second virial coefficients of pure substances

1989 ◽  
Vol 54 (6) ◽  
pp. 1446-1463 ◽  
Author(s):  
Petr Voňka ◽  
Pavel Dittrich ◽  
Josef P. Novák
Keyword(s):  
Equation Of State ◽  
Virial Coefficients ◽  
Effective Algorithm ◽  
Liquid Equilibrium ◽  
Second Virial Coefficients ◽  
Saturated Vapour ◽  
Pure Substances ◽  
Better Than ◽  
Wagner Equation

The temperature dependence of parameter a = a(Tr) of the Redlich-Kwong-Soave equation of state was modified. To calculate the corresponding individual parameters, an effective algorithm applying the Newton method was proposed. The parameters were determined for 60 substances, and the new modification correlates saturated vapour pressures from the values of pr = 0.001 to pr = 1.0 with the accuracy which is usually better than 0.2% and is comparable with that attained in terms of the Wagner equation. The modification proposed is utilized above all when applying the equation of state to the calculation of vapour-liquid equilibrium.

scholarly journals Studies on the Gases Emission under High Temperature Condition from Moulding Sands Bonded by Modified Starch CMS-Na

2017 ◽  
Vol 17 (1) ◽  
pp. 79-82 ◽  
Author(s):  
K. Kaczmarska ◽  
A. Bobrowski ◽  
S. Żymankowska-Kumon ◽  
B. Grabowska
Keyword(s):  
High Temperature ◽  
Potato Starch ◽  
Water Soluble ◽  
Curing Agent ◽  
Chromatography Method ◽  
Benzene Toluene ◽  
Sodium Carboxymethyl Starch ◽  
Btex Compounds

Abstract Emission of gases under high temperature after pouring molten metal into moulds, which contain the organic binder or other additives (solvents or curing agent), may be an important factor influencing both on the quality of the produced castings, and on the state of environment. Therefore, a comprehensive study of the emitted gases would allow to determine restrictions on the use of the moulding sands in foundry technologies, eg. the probability of occurrence of casting defects, and identify the gaseous pollutants emitted to the environment. The aim of the research presented in this paper was to determine the amount of gases that are released at high temperatures from moulding sands bonded by biopolymer binder and the quantitative assessment of the emitted pollutants with particular emphasis on chemical compounds: benzene, toluene, ethylbenzene and xylenes (BTEX). The water-soluble modified potato starch as a sodium carboxymethyl starch with low (CMS-NaL) or high (CMS-NaH) degree of substitution was a binder in the tested moulding sands. A tests of gases emission level were conducted per the procedure developed at the Faculty of Foundry Engineering (AGH University of Science and Technology) involving gas chromatography method (GC). The obtained results of the determination of amount of BTEX compounds generated during the decomposition process of starch binders showed lower emission of aromatic hydrocarbons in comparison with binder based on resin Kaltharz U404 with the acidic curing agent commonly used in the foundries.

Solid–liquid equilibrium of binary and ternary systems formed by ethyl laurate, ethyl palmitate and n-decane: Experimental data and thermodynamic modeling

2016 ◽  
Vol 426 ◽  
pp. 83-94 ◽  
Author(s):  
Maria Dolores Robustillo ◽  
Duclerc Fernandes Parra ◽  
Antonio José de Almeida Meirelles ◽  
Pedro de Alcântara Pessôa Filho
Keyword(s):  
Experimental Data ◽  
Thermodynamic Modeling ◽  
Ternary Systems ◽  
Liquid Equilibrium ◽  
Ethyl Palmitate ◽  
Solid Liquid ◽  
Binary And Ternary Systems
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