Journal: Journal of Chemical & Engineering Data

Abbreviation

J. Chem. Eng. Data

Publisher

American Chemical Society

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ISSN

0021-9568
1520-5134

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Publications 1 - 10 of 13
  • Quaternary Diffusion Coefficients in Liquids from Microfluidics and Raman Microspectroscopy: Cyclohexane + Toluene + Acetone + Methanol
    Item type: Journal Article
    Peters, Christine; Thien, Julia Jutta; Wolff, Ludger Wolfgang Michael; et al. (2020)
    Journal of Chemical & Engineering Data
    Diffusion data in multicomponent liquids are scarce, because these diffusion measurements are time-consuming and laborious. Most diffusion data are therefore available for binary mixtures. While there are at least some data on ternary diffusion, the data on quaternary diffusion are very limited. Therefore, experimental data on multicomponent diffusion are the bottleneck for modeling and understanding mass transport in chemical, biological, and physiological multicomponent systems. In this work, we present the first measurement of quaternary diffusion coefficients using Raman microspectroscopy in a H-cell microchannel. This measurement method provides access to quaternary diffusion coefficients even from a single experiment. Three experiments are sufficient for good precision and low uncertainty. The presented measurement method reduces the experiment time, the sample volume, and the number of experiments. Diffusion coefficients are reported for the quaternary system cyclohexane + toluene + acetone + methanol and its ternary subsystem cyclohexane + toluene + methanol at 298.15 K. For both systems, significant cross-diffusion coefficients were observed even at low concentrations. Despite the molecular interactions, adding acetone as further component to the system reduced the cross-diffusion coefficients by almost 1 order of magnitude showing the complex behavior of multicomponent diffusion. © 2019 American Chemical Society.
  • Volumetric Properties of Mixed Electrolyte Aqueous Solutions at Elevated Temperatures and Pressures. The System KCl–NaCl–H2O to 523.15 K, 40 MPa, and Ionic Strength from (0.1 to 5.8) mol·kg–1
    Item type: Journal Article
    Zezin, Denis; Driesner, Thomas; Sanchez-Valle, Carmen (2014)
    Journal of Chemical & Engineering Data
  • Partition behavior of hexachlorocyclohexane isomers
    Item type: Journal Article
    Goss, Kai-Uwe; Arp, Hans Peter H.; Bronner, Guido; et al. (2008)
    Journal of Chemical & Engineering Data
  • Measurement of Vapor Pressures of Selected PBDEs, Hexabromobenzene, and 1,2-Bis(2,4,6-tribromophenoxy)ethane at Elevated Temperatures
    Item type: Journal Article
    Kuramochi, Hidetoshi; Takigami, Hidetaka; Scheringer, Martin; et al. (2014)
    Journal of Chemical & Engineering Data
  • Volumetric Properties of Na2SO4-H2O and Na2SO4-NaCl-H2O Solutions to 523.15 K, 70 MPa
    Item type: Journal Article
    Zezin, Denis; Driesner, Thomas; Sanchez-Valle, Carmen (2015)
    Journal of Chemical & Engineering Data
  • Corrections to: Volumetric Properties of Na2SO4-H2O and Na2SO4-NaCl-H2O Solutions to 523.15 K, 70 MPa [vol 60, pg 1181, 2015]
    Item type: Other Journal Item
    Zezin, Denis; Driesner, Thomas; Sanchez-Valle, Carmen (2017)
    Journal of Chemical & Engineering Data
  • Multiobjective Optimization of PCP-SAFT Parameters for Water and Alcohols Using Surface Tension Data
    Item type: Journal Article
    Rehner, Philipp; Gross, Joachim (2020)
    Journal of Chemical & Engineering Data
    With predictive methods, such as classical density functional theory and predictive density gradient theory (pDGT), it is possible to model bulk phase properties and interfacial tensions using the same model. For nonassociating fluids, these models can be used to predict interfacial properties for systems that lack experimental data. For associating components, however, predictions often show large deviations to experiments, which is at least partially rooted in highly correlated pure component parameters. Therefore, we use interfacial properties for discriminating pure component parameters by amending the PCP-SAFT parameter estimation for water and alcohols by including surface tension data in the objective function. To obtain a comprehensive comparison between different association models, a multiobjective optimization is performed. By analyzing the resulting pareto fronts, it is shown that including a fitted dipole moment improves the results for water but not for alcohols. The result of the multiobjective optimization is inconclusive about the optimal choice of association scheme for water as the preferred model changes along the pareto front. For small alcohols, in contrast to chemical intuition, the 4C association scheme gives the best results. For longer alcohols, the pareto analysis shows the limits of the homosegmented modeling approach.
  • Automated Physical Property Measurements from Calibration to Data Analysis: Microfluidic Platform for Liquid–Liquid Equilibrium Using Raman Microspectroscopy
    Item type: Journal Article
    Thien, Julia; Reinpold, Lasse; Brands, Thorsten; et al. (2020)
    Journal of Chemical & Engineering Data
    The combination of microfluidics and Raman microspectroscopy has proven to reduce the time and amount of materials required to determine liquid–liquid equilibrium (LLE) data. Until now, the experiments have been conducted manually. However, many applications have shown that the highest efficiency and user independence can be reached by automation. Therefore, we developed an automated setup and workflow from calibration to data analysis for the determination of liquid–liquid equilibrium data using Raman microspectroscopy and a microfluidic platform. Pure components are premixed online using a micromixer, resulting in a closed system with the additional advantage of avoiding potential losses of volatile components. In the automated setup, one experiment generates several data points for calibration and LLE data measurements. The automated setup and workflow are successfully validated with respect to both the integrated calibration and the LLE measurements. For this purpose, we studied two ternary systems (cyclohexane–toluene–methanol and n-heptane–acetonitrile–ethanol) at T = 298.15 K. The presented automated setup is shown to be both accurate and efficient with respect to time and materials for the determination of LLE data.
  • Predicting the Relative Static Permittivity: a Group Contribution Method Based on Perturbation Theory
    Item type: Journal Article
    Rueben, Lisa; Schilling, Johannes; Rehner, Philipp; et al. (2024)
    Journal of Chemical & Engineering Data
    The computer-aided design of (bio)chemical processes requires models that predict thermodynamic properties with as little experimental effort as possible. For the important class of electrolyte systems, the relative static permittivity of the solvent is an important thermodynamic property that depends on the temperature, pressure, composition, and molecular structure of the solvent. This work presents a broadly applicable model for the temperature-dependent relative static permittivity of pure and mixed solvents based on perturbation theory, including a group contribution method. For this purpose, we extend our previous model for polar substances to nonpolar substances. The developed model is parametrized for 785 substances, where permittivity and density data are available in the Dortmund Data Bank and the ThermoML database. Subsequently, a group contribution method is developed to predict the permittivity parameters from the molecular structure. With a mean absolute deviation of 0.2 averaged over all 785 substances, the parametrized model accurately correlates the relative static permittivity over a wide range of permittivities and temperatures. Moreover, the group contribution method achieves a mean absolute deviation of 0.6 for the substances in the training set. A leave-one-out cross-validation shows that the group contribution method accurately predicts substances not included in the training set.
Publications 1 - 10 of 13