Jürgen Gmehling - Academia.edu (original) (raw)
Papers by Jürgen Gmehling
Pure and Applied Chemistry, 2009
Factual data banks nowadays play an important role as a source for thermophysical property data f... more Factual data banks nowadays play an important role as a source for thermophysical property data for use in chemical process simulation, environmental models, and many other computer-based applications. In this work, the historical developments leading to modern factual data banks, the differences compared to other more bibliographically oriented data banks, and their most important applications and future potential will be discussed by using the example of the Dortmund Data Bank (DDB). As the development of the different predictive models for mixtures is covered in a separate publication, this paper focuses on pure-component property estimation, regression of model parameters, test and verification of model parameters prior to process simulation, and advanced topics in process synthesis such as selection of entrainers and data-mining applications.
Journal of Chemical & Engineering Data, 2006
ABSTRACT
Fluid Phase Equilibria, 2011
ABSTRACT
Fluid Phase Equilibria, 2014
This paper presents excess enthalpies for the following systems containing refined vegetable oils... more This paper presents excess enthalpies for the following systems containing refined vegetable oils: soybean oil + methanol (at 353.15 K/722 kPa), soybean oil + ethanol (at 353.15 K/687 kPa and 383.15 K/653 kPa), soybean oil + n-hexane (at 353.15 K/722 kPa and 383.15 K/756 kPa), soybean oil + propan-2-ol (at 298.15 K/998 kPa), sunflower oil + methanol (at 353.15 K/791 kPa), sunflower oil + ethanol (at 353.15 K/894 kPa and 383.15 K/860 kPa), sunflower oil + n-hexane (at 353.15 K/756 kPa and 383.15 K/894 kPa), sunflower oil + propan-2-ol (at 298.15 K/929 kPa), rapeseed oil + methanol (at 353.15 K/963 kPa), rapeseed oil + ethanol (at 353.15 K/998 kPa and 383.15 K/1136 kPa), and rapeseed oil + n-hexane (at 353.15 K/894 kPa and 383.15 K/1136 kPa). The measurements were carried out with a commercially available isothermal flow calorimeter. The experimental H E values have been correlated using the Redlich-Kister polynomial equation. The results for systems with propan-2-ol and some values of partial molar excess enthalpies at infinite dilution, H E,∞ i , obtained in this study have been compared to those available in the literature. The results were also discussed in terms of molecular interactions.
Fluid Phase Equilibria, 2013
The reliable knowledge of the thermodynamic behavior plays a major role for the design of differe... more The reliable knowledge of the thermodynamic behavior plays a major role for the design of different industrial processes. A lot of thermodynamic models do not incorporate electrolyte solutions. For these systems special models have been published. However a lot of these models suffer from the fact that highly concentrated electrolyte solutions cannot be calculated with the desired accuracy which leads to problems when calculating, e.g. salt solubilities. In this article, a revised LIQUAC and LIFAC model is presented, which enables the user to describe mean activity coefficients, osmotic coefficients and also vapor-liquid equilibria reliably. Furthermore the prediction of salt solubilities in aqueous solutions and mixed solvents can be performed successfully. In this paper the predicted data are compared with published data stored in the Dortmund Data Bank. The improvements achieved are additionally shown by a comparison with the results of the original LIQUAC and LIFAC model.
Fluid Phase Equilibria, 2011
The solid–liquid equilibrium of the binary system water (H2O)–dimethyl sulfoxide (DMSO) is invest... more The solid–liquid equilibrium of the binary system water (H2O)–dimethyl sulfoxide (DMSO) is investigated and the results are compared to experimental values to ensure that the applied measurement procedure provides reliable results. After that, the freezing point depression of water is measured in the presence of different amounts of salt. Furthermore solubility measurements are carried out and compared to published experimental
Journal of Chemical & Engineering Data, 2006
Reliable azeotropic data have been measured for the following binary systems: 1-methoxy-2-propano... more Reliable azeotropic data have been measured for the following binary systems: 1-methoxy-2-propanol + toluene, 1-methoxy-2-propanol + cyclohexane, and 2-butoxy ethanol + decane by means of a wire band column. Additionally, molar excess enthalpies (H E) for the four binary systems of benzene and cyclohexane with 1-methoxy-2-propanol and 2-butoxy ethanol at 313.15 K have been measured using an isothermal flow calorimeter. The azeotropic data were compared with predicted data by Modified UNIFAC (Dortmund). The H E data measured are in good agreement with the predicted results using Modified UNIFAC (Dortmund).
Journal of Chemical & Engineering Data, 2001
Vapor-liquid equilibrium (VLE), excess enthalpy (H E), and vapor pressure (P i s) data for eight ... more Vapor-liquid equilibrium (VLE), excess enthalpy (H E), and vapor pressure (P i s) data for eight binary systems containing cis-1-chloropropene, trans-1-chloropropene, 1,2-dichloropropane, 1,2-propanediol, 1,2propylene glycol diacetate, propylene oxide, and water are presented in a temperature range from 276 to 368 K. The VLE and vapor pressure data were obtained by means of a computer-controlled static apparatus, and the heat of mixing data were measured using an isothermal flow calorimeter. Temperaturedependent NRTL interaction parameters were regressed by a simultaneous correlation of the experimental VLE and H E data. These parameters are required for a proper simulation of the different separation steps in the chlorohydrin process for the production of propylene oxide.
Journal of Chemical & Engineering …, 2001
... Fiege, C.; Joh, R.; Petri, M.; Gmehling, J. Solid−Liquid Equilibria for Different ... Laura C... more ... Fiege, C.; Joh, R.; Petri, M.; Gmehling, J. Solid−Liquid Equilibria for Different ... Laura C. Draucker, Malina Janakat, Michael J. Lazzaroni, David Bush, and Charles A. Eckert, Timothy C. FrankJames D. Olson,. Industrial & Engineering Chemistry Research 2007 46 (7), 2198-2204. ...
Fluid Phase Equilibria, 2002
The predictive Soave-Redlich-Kwong (PSRK) equation of state (EOS) is a well-established method fo... more The predictive Soave-Redlich-Kwong (PSRK) equation of state (EOS) is a well-established method for the prediction of thermodynamic properties required in process simulation. But there are still some problems to be solved, e.g. the reliability for strong asymmetric mixtures of components which are very different in size. The following modifications are introduced in the PSRK mixing rules: the Flory-Huggins term in the mixing rule for the EOS parameter a, and the combinatorial part in the UNIFAC model are skipped simultaneously; a nonlinear mixing rule for the EOS parameter b, instead of the linear mixing rule, is proposed. With these two modifications better results are obtained for vapor-liquid equilibria and activity coefficients at infinite dilution for alkane-alkane systems, specially for asymmetric systems. In order to obtain better results for enthalpy of mixing, temperature-dependent parameters are used. Group interaction parameters have been fitted for several groups, and the results are compared with the Modified UNIFAC (Dortmund), and the PSRK methods.
Fluid Phase Equilibria, 2001
Reliable azeotropic data have been measured for the binary systems ethanol+diethoxymethane, dieth... more Reliable azeotropic data have been measured for the binary systems ethanol+diethoxymethane, diethoxymethane+1-propanol, diethoxymethane+heptane, and cyclohexane+diethoxymethane with the help of a wire band column. Additionally molar excess enthalpies (HE) for the binary mixtures of diethoxymethane with hexane, 1-octene, methanol and ethanol at 363.15K have been determined with an isothermal flow calorimeter. The experimental data were compared with the results using the
Industrial & Engineering Chemistry Research, 2004
The predictive Soave-Redlich-Kwong (PSRK) group contribution equation of state, which is commonly... more The predictive Soave-Redlich-Kwong (PSRK) group contribution equation of state, which is commonly used for the prediction of phase equilibria with subcritical as well as supercritical compounds, was extended to electrolyte systems by linking it to the group contribution model LIFAC. The approach was at first evaluated by applying it for the calculation of vapor-liquid equilibrium (VLE) data of binary and ternary electrolyte systems (two solvents + one salt) using the published PSRK and LIFAC group interaction parameters. For the reliable description of gas solubility data, 16 new group interaction parameter sets (gas-ion interactions) were finally added to the current PSRK parameter matrix. For fitting the required interaction parameters, a large number of gas solubility data are required. These data have either been measured up to 10 MPa by means of a static synthetic method or taken from the literature. Typical results for the prediction of methane, carbon dioxide, and nitrogen solubility in aqueous electrolyte mixtures are presented over a wide concentration, temperature, and pressure range.
Journal of Chemical …, 2006
Densities in the liquid phase were measured for (1,1,1,2-tetrafluoroethane + triethylene glycol d... more Densities in the liquid phase were measured for (1,1,1,2-tetrafluoroethane + triethylene glycol dimethyl ether) using a vibrating-tube densimeter. Three mixtures with a molar fraction of refrigerant of 0.9485, 0.9655, and 0.9798 have been considered at temperatures from (283 to 323 K) at pressures up to 6 MPa. Such ranges are approximately those of interest for a compression refrigeration plant. The data at each composition were correlated with a Tait equation, and the excess volumes were also provided.
Journal of Chemical & …, 1999
Isothermal vapor-liquid equilibrium (VLE) and excess enthalpy (H E) data are reported for the sys... more Isothermal vapor-liquid equilibrium (VLE) and excess enthalpy (H E) data are reported for the system propionic aldehyde + 2-methyl-2-butanol at 333.15 K. The data were measured by means of a computeroperated static apparatus and isothermal flow calorimetry, respectively. The experimental data were correlated simultaneously by using linear temperature-dependent UNIQUAC parameters.
Journal of Chemical & …, 1999
... Dry air in the 50 L ballast tank entered the system via an automatically controlled needle va... more ... Dry air in the 50 L ballast tank entered the system via an automatically controlled needle valve (H1). ... To confirm the reliability of the experimental VLE data, each experimental point for the salt-free system acetone (1) + methanol (2) was measured twice at 101.33 kPa. ...
The Journal of Chemical Thermodynamics, 2013
Fluid Phase Equilibria, 2015
ABSTRACT Thermodynamic properties, in particular vapor–liquid equilibrium (VLE) data, are require... more ABSTRACT Thermodynamic properties, in particular vapor–liquid equilibrium (VLE) data, are required for the development of reliable predictive models for systems with fatty compounds. Isothermal VLE data have been measured for mixtures of methanol, ethanol, or n-hexane with refined vegetable oils (soybean, sunflower and rapeseed) at 348.15 K and 373.15 K using a computer-driven static apparatus. The oils were characterized in terms of their fatty acid and corresponding triacylglycerol (TAG) compositions. For the mixtures containing vegetable oils and n-hexane a negative deviation from Raoult’s law was observed and a homogeneous behavior (no miscibility gap) was found, while the mixtures with alcohols exhibited positive deviation from ideal behavior and, in some cases, limited miscibility. On the basis of the composition of the studied vegetable oils, their relative van der Waals volume and surface area parameters were estimated by the Bondi method and their vapor pressure by a group contribution method developed by Ceriani and Meirelles [1]. The experimental VLE data were correlated together with available excess enthalpies ( ) and activity coefficients at infinite dilution ( ) data using the UNIQUAC model. For the fitting process the refined vegetable oil was treated as a single triacylglycerol (pseudo-component) which has the corresponding degree of unsaturation, number of carbon atoms and molar mass of the original oil composition. The overall-average errors (AAE) using UNIQUAC model are 4.46% for VLE, 7.07% for and 5.80% for The experimental data were also compared with the predicted results using mod. UNIFAC (Dortmund) and an extension of this method proposed for triacylglycerols in a previous work was also tested.
Journal of Chemical & Engineering Data, 2007
The vapor pressures of (butyric acid + toluene) and of the pure components were measured by means... more The vapor pressures of (butyric acid + toluene) and of the pure components were measured by means of a static device at temperatures between (273 and 363) K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions were calculated for several constant temperatures and fitted to a fourth-order Redlich-Kister equation. The system shows positive deviation from ideality. Additionally, molar excess enthalpies, H E , for the binary (butyric acid + toluene) system have been measured at 323.15 K using an isothermal flow calorimeter.
Journal of Chemical & Engineering Data, 2006
ABSTRACT
Pure and Applied Chemistry, 2009
Factual data banks nowadays play an important role as a source for thermophysical property data f... more Factual data banks nowadays play an important role as a source for thermophysical property data for use in chemical process simulation, environmental models, and many other computer-based applications. In this work, the historical developments leading to modern factual data banks, the differences compared to other more bibliographically oriented data banks, and their most important applications and future potential will be discussed by using the example of the Dortmund Data Bank (DDB). As the development of the different predictive models for mixtures is covered in a separate publication, this paper focuses on pure-component property estimation, regression of model parameters, test and verification of model parameters prior to process simulation, and advanced topics in process synthesis such as selection of entrainers and data-mining applications.
Journal of Chemical & Engineering Data, 2006
ABSTRACT
Fluid Phase Equilibria, 2011
ABSTRACT
Fluid Phase Equilibria, 2014
This paper presents excess enthalpies for the following systems containing refined vegetable oils... more This paper presents excess enthalpies for the following systems containing refined vegetable oils: soybean oil + methanol (at 353.15 K/722 kPa), soybean oil + ethanol (at 353.15 K/687 kPa and 383.15 K/653 kPa), soybean oil + n-hexane (at 353.15 K/722 kPa and 383.15 K/756 kPa), soybean oil + propan-2-ol (at 298.15 K/998 kPa), sunflower oil + methanol (at 353.15 K/791 kPa), sunflower oil + ethanol (at 353.15 K/894 kPa and 383.15 K/860 kPa), sunflower oil + n-hexane (at 353.15 K/756 kPa and 383.15 K/894 kPa), sunflower oil + propan-2-ol (at 298.15 K/929 kPa), rapeseed oil + methanol (at 353.15 K/963 kPa), rapeseed oil + ethanol (at 353.15 K/998 kPa and 383.15 K/1136 kPa), and rapeseed oil + n-hexane (at 353.15 K/894 kPa and 383.15 K/1136 kPa). The measurements were carried out with a commercially available isothermal flow calorimeter. The experimental H E values have been correlated using the Redlich-Kister polynomial equation. The results for systems with propan-2-ol and some values of partial molar excess enthalpies at infinite dilution, H E,∞ i , obtained in this study have been compared to those available in the literature. The results were also discussed in terms of molecular interactions.
Fluid Phase Equilibria, 2013
The reliable knowledge of the thermodynamic behavior plays a major role for the design of differe... more The reliable knowledge of the thermodynamic behavior plays a major role for the design of different industrial processes. A lot of thermodynamic models do not incorporate electrolyte solutions. For these systems special models have been published. However a lot of these models suffer from the fact that highly concentrated electrolyte solutions cannot be calculated with the desired accuracy which leads to problems when calculating, e.g. salt solubilities. In this article, a revised LIQUAC and LIFAC model is presented, which enables the user to describe mean activity coefficients, osmotic coefficients and also vapor-liquid equilibria reliably. Furthermore the prediction of salt solubilities in aqueous solutions and mixed solvents can be performed successfully. In this paper the predicted data are compared with published data stored in the Dortmund Data Bank. The improvements achieved are additionally shown by a comparison with the results of the original LIQUAC and LIFAC model.
Fluid Phase Equilibria, 2011
The solid–liquid equilibrium of the binary system water (H2O)–dimethyl sulfoxide (DMSO) is invest... more The solid–liquid equilibrium of the binary system water (H2O)–dimethyl sulfoxide (DMSO) is investigated and the results are compared to experimental values to ensure that the applied measurement procedure provides reliable results. After that, the freezing point depression of water is measured in the presence of different amounts of salt. Furthermore solubility measurements are carried out and compared to published experimental
Journal of Chemical & Engineering Data, 2006
Reliable azeotropic data have been measured for the following binary systems: 1-methoxy-2-propano... more Reliable azeotropic data have been measured for the following binary systems: 1-methoxy-2-propanol + toluene, 1-methoxy-2-propanol + cyclohexane, and 2-butoxy ethanol + decane by means of a wire band column. Additionally, molar excess enthalpies (H E) for the four binary systems of benzene and cyclohexane with 1-methoxy-2-propanol and 2-butoxy ethanol at 313.15 K have been measured using an isothermal flow calorimeter. The azeotropic data were compared with predicted data by Modified UNIFAC (Dortmund). The H E data measured are in good agreement with the predicted results using Modified UNIFAC (Dortmund).
Journal of Chemical & Engineering Data, 2001
Vapor-liquid equilibrium (VLE), excess enthalpy (H E), and vapor pressure (P i s) data for eight ... more Vapor-liquid equilibrium (VLE), excess enthalpy (H E), and vapor pressure (P i s) data for eight binary systems containing cis-1-chloropropene, trans-1-chloropropene, 1,2-dichloropropane, 1,2-propanediol, 1,2propylene glycol diacetate, propylene oxide, and water are presented in a temperature range from 276 to 368 K. The VLE and vapor pressure data were obtained by means of a computer-controlled static apparatus, and the heat of mixing data were measured using an isothermal flow calorimeter. Temperaturedependent NRTL interaction parameters were regressed by a simultaneous correlation of the experimental VLE and H E data. These parameters are required for a proper simulation of the different separation steps in the chlorohydrin process for the production of propylene oxide.
Journal of Chemical & Engineering …, 2001
... Fiege, C.; Joh, R.; Petri, M.; Gmehling, J. Solid−Liquid Equilibria for Different ... Laura C... more ... Fiege, C.; Joh, R.; Petri, M.; Gmehling, J. Solid−Liquid Equilibria for Different ... Laura C. Draucker, Malina Janakat, Michael J. Lazzaroni, David Bush, and Charles A. Eckert, Timothy C. FrankJames D. Olson,. Industrial & Engineering Chemistry Research 2007 46 (7), 2198-2204. ...
Fluid Phase Equilibria, 2002
The predictive Soave-Redlich-Kwong (PSRK) equation of state (EOS) is a well-established method fo... more The predictive Soave-Redlich-Kwong (PSRK) equation of state (EOS) is a well-established method for the prediction of thermodynamic properties required in process simulation. But there are still some problems to be solved, e.g. the reliability for strong asymmetric mixtures of components which are very different in size. The following modifications are introduced in the PSRK mixing rules: the Flory-Huggins term in the mixing rule for the EOS parameter a, and the combinatorial part in the UNIFAC model are skipped simultaneously; a nonlinear mixing rule for the EOS parameter b, instead of the linear mixing rule, is proposed. With these two modifications better results are obtained for vapor-liquid equilibria and activity coefficients at infinite dilution for alkane-alkane systems, specially for asymmetric systems. In order to obtain better results for enthalpy of mixing, temperature-dependent parameters are used. Group interaction parameters have been fitted for several groups, and the results are compared with the Modified UNIFAC (Dortmund), and the PSRK methods.
Fluid Phase Equilibria, 2001
Reliable azeotropic data have been measured for the binary systems ethanol+diethoxymethane, dieth... more Reliable azeotropic data have been measured for the binary systems ethanol+diethoxymethane, diethoxymethane+1-propanol, diethoxymethane+heptane, and cyclohexane+diethoxymethane with the help of a wire band column. Additionally molar excess enthalpies (HE) for the binary mixtures of diethoxymethane with hexane, 1-octene, methanol and ethanol at 363.15K have been determined with an isothermal flow calorimeter. The experimental data were compared with the results using the
Industrial & Engineering Chemistry Research, 2004
The predictive Soave-Redlich-Kwong (PSRK) group contribution equation of state, which is commonly... more The predictive Soave-Redlich-Kwong (PSRK) group contribution equation of state, which is commonly used for the prediction of phase equilibria with subcritical as well as supercritical compounds, was extended to electrolyte systems by linking it to the group contribution model LIFAC. The approach was at first evaluated by applying it for the calculation of vapor-liquid equilibrium (VLE) data of binary and ternary electrolyte systems (two solvents + one salt) using the published PSRK and LIFAC group interaction parameters. For the reliable description of gas solubility data, 16 new group interaction parameter sets (gas-ion interactions) were finally added to the current PSRK parameter matrix. For fitting the required interaction parameters, a large number of gas solubility data are required. These data have either been measured up to 10 MPa by means of a static synthetic method or taken from the literature. Typical results for the prediction of methane, carbon dioxide, and nitrogen solubility in aqueous electrolyte mixtures are presented over a wide concentration, temperature, and pressure range.
Journal of Chemical …, 2006
Densities in the liquid phase were measured for (1,1,1,2-tetrafluoroethane + triethylene glycol d... more Densities in the liquid phase were measured for (1,1,1,2-tetrafluoroethane + triethylene glycol dimethyl ether) using a vibrating-tube densimeter. Three mixtures with a molar fraction of refrigerant of 0.9485, 0.9655, and 0.9798 have been considered at temperatures from (283 to 323 K) at pressures up to 6 MPa. Such ranges are approximately those of interest for a compression refrigeration plant. The data at each composition were correlated with a Tait equation, and the excess volumes were also provided.
Journal of Chemical & …, 1999
Isothermal vapor-liquid equilibrium (VLE) and excess enthalpy (H E) data are reported for the sys... more Isothermal vapor-liquid equilibrium (VLE) and excess enthalpy (H E) data are reported for the system propionic aldehyde + 2-methyl-2-butanol at 333.15 K. The data were measured by means of a computeroperated static apparatus and isothermal flow calorimetry, respectively. The experimental data were correlated simultaneously by using linear temperature-dependent UNIQUAC parameters.
Journal of Chemical & …, 1999
... Dry air in the 50 L ballast tank entered the system via an automatically controlled needle va... more ... Dry air in the 50 L ballast tank entered the system via an automatically controlled needle valve (H1). ... To confirm the reliability of the experimental VLE data, each experimental point for the salt-free system acetone (1) + methanol (2) was measured twice at 101.33 kPa. ...
The Journal of Chemical Thermodynamics, 2013
Fluid Phase Equilibria, 2015
ABSTRACT Thermodynamic properties, in particular vapor–liquid equilibrium (VLE) data, are require... more ABSTRACT Thermodynamic properties, in particular vapor–liquid equilibrium (VLE) data, are required for the development of reliable predictive models for systems with fatty compounds. Isothermal VLE data have been measured for mixtures of methanol, ethanol, or n-hexane with refined vegetable oils (soybean, sunflower and rapeseed) at 348.15 K and 373.15 K using a computer-driven static apparatus. The oils were characterized in terms of their fatty acid and corresponding triacylglycerol (TAG) compositions. For the mixtures containing vegetable oils and n-hexane a negative deviation from Raoult’s law was observed and a homogeneous behavior (no miscibility gap) was found, while the mixtures with alcohols exhibited positive deviation from ideal behavior and, in some cases, limited miscibility. On the basis of the composition of the studied vegetable oils, their relative van der Waals volume and surface area parameters were estimated by the Bondi method and their vapor pressure by a group contribution method developed by Ceriani and Meirelles [1]. The experimental VLE data were correlated together with available excess enthalpies ( ) and activity coefficients at infinite dilution ( ) data using the UNIQUAC model. For the fitting process the refined vegetable oil was treated as a single triacylglycerol (pseudo-component) which has the corresponding degree of unsaturation, number of carbon atoms and molar mass of the original oil composition. The overall-average errors (AAE) using UNIQUAC model are 4.46% for VLE, 7.07% for and 5.80% for The experimental data were also compared with the predicted results using mod. UNIFAC (Dortmund) and an extension of this method proposed for triacylglycerols in a previous work was also tested.
Journal of Chemical & Engineering Data, 2007
The vapor pressures of (butyric acid + toluene) and of the pure components were measured by means... more The vapor pressures of (butyric acid + toluene) and of the pure components were measured by means of a static device at temperatures between (273 and 363) K. The data were correlated with the Antoine equation. From these data, excess Gibbs functions were calculated for several constant temperatures and fitted to a fourth-order Redlich-Kister equation. The system shows positive deviation from ideality. Additionally, molar excess enthalpies, H E , for the binary (butyric acid + toluene) system have been measured at 323.15 K using an isothermal flow calorimeter.
Journal of Chemical & Engineering Data, 2006
ABSTRACT