scholarly journals New Fitting Method for Vapour-Liquid Equilibrium Data and its Application for Ethanol-Water Distillation Process Modeling

2020 ◽  
Vol 71 (7) ◽  
pp. 114-125
Author(s):  
Csaba Dezso Andras ◽  
Eva Molnos ◽  
Laszlo Matyas ◽  
Alexandru Szep
Keyword(s):  
Simple Calculation ◽  
Continuous Functions ◽  
Water Mixture ◽  
Liquid Equilibrium ◽  
Water Distillation ◽  
Azeotropic Mixtures ◽  
Fitting Method ◽  
Equilibrium Data ◽  
Vle Data ◽  
Discrete Values

For modeling and simulation of distillation processes, the main information required is the vapour-liquid equilibrium (VLE) data. These are available as discrete values, but for modeling purpose, an analytical function would be more suitable. We developed a simple calculation protocol to obtain a single continuous function for the VLE curve on the entire concentration domain, without using thermodynamic functions. The fitting parameters of binary ethanol-water mixture VLE curve were determined. The methodology is suitable for fitting continuous functions on VLE data of any binary or multicomponent, non-ideal (even azeotropic) mixtures.

Isobaric Vapor-Liquid Equilibria of Hexamethyl Disiloxane + Ethyl Acetate System at Normal Pressure

2011 ◽  
Vol 396-398 ◽  
pp. 968-972
Author(s):  
Wen Lin Zhang ◽  
Nan Meng ◽  
Ru Yi Sun ◽  
Chun Li Li
Keyword(s):  
Experimental Data ◽  
Ethyl Acetate ◽  
Normal Pressure ◽  
Liquid Equilibrium ◽  
Vapor Liquid Equilibrium ◽  
Equilibrium Data ◽  
Vle Data ◽  
Vapor Liquid Equilibria ◽  
Ethyl Acetate System ◽  
Vapor Liquid

Vapor-liquid equilibrium data of hexamethyl disiloxane + ethyl acetate system at 101.3kPa were measured by using double circulating vapor-liquid equilibrium still. The thermodynamic consistency of the VLE data was examined by Herrington method. Experimental data was correlated by NRTL and UNIQUAC parameter models. Both of the models satisfactorily correlated with the VLE data. The result showed that the NRTL model was the most suitable one to represent experimental data satisfactorily and the system had a minimum temperature azeotrope at 350.31 K and the mole azeotropic composition was 0.0330.

scholarly journals Predictions of the vapor-liquid equilibrium data for low-GWP Hydrofluorocarbons + polyethylene-glycol dimethylether solvents by modified UNIFAC model

2021 ◽  
Vol 267 ◽  
pp. 02052
Author(s):  
Xiao Zhang ◽  
Liang Cai ◽  
Jingyi Qiao
Keyword(s):  
Experimental Data ◽  
Polyethylene Glycol ◽  
Large Deviations ◽  
Absorption Refrigeration ◽  
Refrigeration System ◽  
Liquid Equilibrium ◽  
Unifac Model ◽  
Equilibrium Data ◽  
Vle Data ◽  
Absorption Refrigeration System

The working fluids are crucial for developing the absorption refrigeration system. Our previous work has proposed three novel working pairs, which uses the low-GWP HFCs (R32, R152a and R161) as the refrigerants and the polyethylene-glycol dimethylether solvent DMETEG as the absorbent. To explore the VLE behaviors of HFCs in other longer chain structures of polyethylene-glycol dimethylether solvents, the modified UNIFAC (Dortmund) model was applied for prediction. The previous binary parameters showed large deviations from the experimental data. Then the new binary parameters were obtained by regression. For R32+DMEDEG and R152a/R161+DMETrEG, the prediction ARAD results were reduced from 17.13%, 24.06% and 12.48% to 3.71%, 2.61% and 6.86%, respectively. Finally, the VLE data of R161 + PGDE at the temperatures of 293.15-343.15K were predicted.

scholarly journals Use of the SSF equations in the Kojima-Moon-Ochi thermodynamic consistency test of isothermal vapour-liquid equilibrium data

2000 ◽  
Vol 65 (12) ◽  
pp. 877-889
Author(s):  
Jelena Jelic ◽  
Aleksandar Tasic ◽  
Bojan Djordjevic ◽  
Slobodan Serbanovic
Keyword(s):  
Experimental Data ◽  
Binary Systems ◽  
Thermodynamic Consistency ◽  
Data Sets ◽  
Liquid Equilibrium ◽  
Consistency Test ◽  
Equilibrium Data ◽  
Vle Data ◽  
Kister Equation

The Kojima-Moon-Ochi (KMO) thermodynamic consistency test of vapour-liquid equilibrium (VLE) measurements for 32 isothermal data sets of binary systems of various complexity was applied using two fitting equations: the Redlich-Kister equation and the Sum of Symmetrical Functions. It was shown that the enhanced reliability of the fitting of the experimental data can change the conclusions drawn on their thermodynamic consistency in those cases of VLE data sets that are estimated to be near the border of consistency.

scholarly journals Measurement and Correlation of Isobaric Vapor-Liquid Equilibrium Data for Water + 2-Azido-N,N-Dimethylethanamine System at 4 kPa

2021 ◽  
Vol 15 (2) ◽  
pp. 226-232
Author(s):  
Hosein Rouhandeh ◽  
◽  
Shahram Ghanbari Pakdehi ◽  
Keyword(s):  
Standard Deviation ◽  
Activity Coefficient ◽  
Liquid Equilibrium ◽  
Absolute Deviation ◽  
Vapor Liquid Equilibrium ◽  
Azeotropic Point ◽  
Activity Coefficient Model ◽  
Equilibrium Data ◽  
Vle Data ◽  
Vapor Liquid

Isobaric vapor-liquid equilibrium (VLE) data for binary system of water + 2-azido-N,N-dimethylethanamine (DMAZ) was measured at 4 kPa. The results showed an azeotropic point at x1 = 0.985 and T = 302.17 K. The data was correlated with nonrandom two-liquid (NRTL), Wilson and universal quasi-chemical activity coefficient (UNIQUAC) models for the liquid phase. A comparison of the model performances was made using of the criterion of the average absolute deviation, standard deviation and mean standard deviation in boiling-point temperature. The results indicated that the NRTL activity coefficient model satisfactorily correlated the VLE data.

Vapour-phase non-ideality in low-pressure vapour-liquid equilibrium data correlation

1980 ◽  
Vol 45 (11) ◽  
pp. 3057-3062 ◽  
Author(s):  
Jan Linek
Keyword(s):  
Experimental Data ◽  
Phase Composition ◽  
Liquid Phase ◽  
Low Pressure ◽  
Vapour Phase ◽  
Liquid Equilibrium ◽  
Ideal Behavior ◽  
Equilibrium Data ◽  
Vle Data ◽  
Volumetric Behavior

The effect of vapour-phase imperfections and the volumetric behavior of liquid phase on the low-pressure VLE data reduction was investigated. The errors in the vapour-phase composition due to processing experimental data assuming ideal behavior of the vapour phase were evaluated.

Isothermal and isobaric vapour-liquid equilibrium data in the tetrachloromethane-sec-butyl alcohol system

1983 ◽  
Vol 48 (9) ◽  
pp. 2446-2453 ◽  
Author(s):  
Jan Linek
Keyword(s):  
Experimental Data ◽  
Boiling Point ◽  
Butyl Alcohol ◽  
Correlation Equations ◽  
Wilson Equation ◽  
Liquid Equilibrium ◽  
Raoult’S Law ◽  
System A ◽  
Equilibrium Data ◽  
Alcohol System

Isothermal vapour-liquid equilibrium data at 65, 73 and 80 °C and isobaric ones at 101.3 kPa were measured in the tetrachloromethane-sec-butyl alcohol system. A modified circulation still of the Gillespie type was used for the measurements. Under the conditions of measurement, the system exhibits positive deviations from Raoult's law and minimum boiling-point azeotropes. The experimental data were fitted to a number of correlation equations, the most suitable being the Wilson equation.

Vapour-liquid equilibrium in the ternary system cyclohexane-acetic acid-propionic acid

1989 ◽  
Vol 54 (11) ◽  
pp. 2840-2847 ◽  
Author(s):  
Ivona Malijevská ◽  
Alena Maštalková ◽  
Marie Sýsová
Keyword(s):  
Acetic Acid ◽  
Ternary System ◽  
Propionic Acid ◽  
Activity Coefficients ◽  
Error Propagation ◽  
Analytical Techniques ◽  
Liquid Equilibrium ◽  
Consistency Test ◽  
Propagation Law ◽  
Equilibrium Data

Isobaric equilibrium data (P = 101.3 kPa) for the system cyclohexane-acetic acid-propionic acid have been measured by two different analytical techniques. Activity coefficients calculated by simultaneous solving of equations for the chemical and phase equilibria were subjected to a consistency test based on inaccuracies determined from the error propagation law, and were correlated by Wilson’s equation. The activity coefficients measured were compared with those calculated from binary vapour-liquid equilibrium data and with values predicted by the UNIFAC method.

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