Dew-Point Densities of Fluid Mixtures - New Approaches for Measurement and Modeling

• Applicant: Professor Dr.-Ing. Markus Richter
• Subject Area: Technical Thermodynamics
• Term: from 2015 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 269357610

• Final Report Year: 2022

Final Report Abstract

For the accurate measurement of the dew-point densities of fluid mixtures, new measurement methods were developed within the scope of the Emmy Noether Group, which make it possible to quantify sorption effects near the dew line that distort the measurement data, in order to be able to correct them. For this purpose, the two-sinker densimeter at the National Institute of Standards and Technology was used, which was modified in such a way that independent weighings of a density sinker and a sorption sinker could be carried out inside the measuring cell. In addition, a commercial magnetic suspension balance for measurements on adsorbents with large specific surface areas was optimized into a so-called tandem sinker densimeter in order to be able to perform accurate density measurements in combination with sorption measurements on quasi non-porous metallic surfaces (i.e. those of sinkers). However, both measurement methods are limited in terms of low measurement uncertainty, which is why a precision density measurement system based on the newly developed four-sinker principle was set up. In this new method, two density sinkers are used to apply the established two-sinker method as a differential method for high-precision density measurements; two additional sorption sinkers are used to determine the distorting sorption effects with very low measurement uncertainty for the first time. In total, different measurement series were performed with CO2, C2H6 and C3H8 as well as on the binary systems (Ar + CO2), (C2H6 + CO2), (C3H8 + CO2), (H2 + CO2) and (CH4 + C3H8). The measured data were used to develop an empirical correction model that allows, for the first time, to correct measurements near the dew line distorted by sorption effects. Analysis of the experimental data revealed the need to develop a better understanding of the surface phenomena occurring at the atomistic level, so molecular dynamics simulations were performed in the NVT ensemble. The simulation of adsorption isotherms up to the dew point on quasi-non porous metallic surfaces, incorporating the real surface structure, is initially laborious and non-trivial. Nevertheless, the simulations have shown that they offer the potential to improve the empirical correction model developed in this project in the future, so that ultimately an accurate determination of dew-point densities of fluid mixtures becomes possible.

Publications

• A novel experimental approach for the investigation of sorption phenomena near dew points of fluid mixtures. Poster, 12th International Conference on the Fundamentals of Adsorption, Friedrichshafen, Germany, 2016
  Richter, M. & McLinden, M. O.
  
• Application of a two-sinker densimeter for phase-equilibrium measurements: A new technique for the detection of dew points and measurements on the (methane + propane) system. The Journal of Chemical Thermodynamics, 99, 105-115.
  McLinden, Mark O. & Richter, Markus
  
• Development of a special densimeter for the investigation of sorption phenomena near dew points of fluid mixtures. Poster, Thermodynamik-Kolloquium, Kaiserslautern, Germany, 2016.
  Moritz, K.; Kleinrahm, R.; McLinden, M. O. & Richter, M.
  
• Application of a commercial densimeter to compare sorption phenomena on porous and nonporous media. Talk, European Conference on Thermophysical Properties, Graz, Austria, 2017
  Yang., X.; Ben Souissi, M. A.; Kleinrahm, R.; McLinden, M. O. & Richter, M.
  
• Densimetry for the Quantification of Sorption Phenomena on Nonporous Media Near the Dew Point of Fluid Mixtures. Scientific Reports, 7(1).
  Richter, Markus & McLinden, Mark O.
  
• Development of a new densimeter for the combined investigation of dew-point densities and sorption phenomena of fluid mixtures. Measurement Science and Technology, 28(12), 127004.
  Moritz, Katharina; Kleinrahm, Reiner; McLinden, Mark O. & Richter, Markus
  
• Dew- Point densities of fluid mixtures – New approaches for measurement and modeling. Vortrag, Thermodynamik-Kolloquium, Dresden, Germany, 2017
  Ben Souissi, M. A.; McLinden, M. O.; Moritz, K.; Richter, M.; Tietz, C. & Yang, X.
  
• Linking Densimetry and Molecular Simulation to Quantify Sorption Phenomena on Nonporous Surfaces. Poster, SAFT Konferenz, Heidelberg, Germany, 2017
  Tietz, C. & Richter, M.
  
• Quantification of sorption phenomena on nonporous media near mixture dew points by densimetry. Talk, European Conference on Thermophysical Properties, Graz, Austria, 2017
  Richter. M.; McLinden, M. O.; Kleinrahm, R.; Moritz, K. & Tietz, C.
  
• Vapor-Phase (p, ρ, T, x) Behavior and Virial Coefficients for the Binary Mixture (0.05 Hydrogen + 0.95 Carbon Dioxide) over the Temperature Range from (273.15 to 323.15) K with Pressures up to 6 MPa. Journal of Chemical & Engineering Data, 62(9), 2973-2981.
  Ben, Souissi Mohamed A.; Kleinrahm, Reiner; Yang, Xiaoxian & Richter, Markus
  
• Development of a Special Densimeter for the Investigation of Sorption Phenomena Near Dew Points of Fluid Mixtures. Vortrag, 20th Symposium on Thermophysical Properties, Boulder (CO), USA, 2018
  Moritz, K.; Kleinrahm, R.; McLinden, M. O. & Richter, M.
  
• Dew-Point Densities of Fluid Mixtures - An Outlook for New Experimental and Modeling Approaches. Eingeladener Vortrag, 20th Symposium on Thermophysical Properties, Boulder (CO), USA, 2018
  Richter, M.; Moritz, K.; Kleinrahm, R.; McLinden, M. O.; Yang, X. & Tietz, C.
  
• Linking Fluid-Mixture Densimetry and Molecular Simulation for the Quantification of Sorption Phenomena on Nonporous Metal Surfaces. Vortrag, 20th Symposium on Thermophysical Properties, Boulder (CO), USA, 2018
  Tietz, C. & Richter, M.
  
• Measurement of sorption phenomena near dew points of fluid mixtures: concept for the combination of gravimetric sorption analysis and Raman spectroscopy. Measurement Science and Technology, 29(10), 105501.
  Lipinski, Gregor; Holzammer, Christine; Petermann, Marcus & Richter, Markus
  
• Systematic Investigation of the Force Transmission Error in a Tandem-Sinker Densimeter Based on a Magnetic- Suspension Balance. Vortrag, 20th Symposium on Thermophysical Properties, Boulder (CO), USA, 2018
  Yang., X.; McLinden, M. O.; Kleinrahm, R. & Richter, M.
  
• Vapour-phase (p, ρ, T, x) behaviour and virial coefficients for the (ethane + carbon dioxide) system. The Journal of Chemical Thermodynamics, 122, 204-213.
  Yang, Xiaoxian; Ben, Souissi Mohamed A.; Kleinrahm, Reiner & Richter, Markus
  
• Analysis of the systematic force-transmission error of the magnetic-suspension coupling in single-sinker densimeters and commercial gravimetric sorption analyzers. Adsorption, 25(4), 717-735.
  Kleinrahm, Reiner; Yang, Xiaoxian; McLinden, Mark O. & Richter, Markus
  
• Experimental Investigation of Surface Phenomena on Quasi Nonporous and Porous Materials Near Dew Points of Pure Fluids and Their Mixtures. Industrial & Engineering Chemistry Research, 59(7), 3238-3251.
  Yang, Xiaoxian & Richter, Markus
  
• Linking Fluid Densimetry and Molecular Simulation: Adsorption Behavior of Carbon Dioxide on Planar Gold Surfaces. Industrial & Engineering Chemistry Research, 59(29), 13283-13289.
  Tietz, Christopher; Sekulla, Markus; Yang, Xiaoxian; Schmid, Rochus & Richter, Markus
  
• Uncertainty analysis of adsorption measurements using commercial gravimetric sorption analyzers with simultaneous density measurement based on a magnetic-suspension balance. Adsorption, 26(4), 645-659.
  Yang, Xiaoxian; Kleinrahm, Reiner; McLinden, Mark O. & Richter, Markus
  
• Combination of Molecular Dynamics Simulation and Gravimetric Experiments: The Key to Accurate Dew-Point Densities? Poster, 21th Symposium on Thermophysical Properties, Boulder (CO), USA, 2021
  Bernardini, L.; Sekulla, M. & Richter, M.
  
• Raman Sensor for the Determination of Gas Solubility. Physchem, 1(2), 176-188.
  Lipinski, Gregor & Richter, Markus
  
• The Four-Sinker Densimeter – A new Gravimetric Apparatus for Accurate Measurements of Fluid Mixture Dew-Point Densities. Vortrag, 21th Symposium on Thermophysical Properties, Boulder (CO), USA, 2021
  Moritz, K.; Kleinrahm, R.; McLinden, M. O.; Bernardini, L. & Richter, M.
  
• Application of Raman Spectroscopy for Sorption Analysis of Functionalized Porous Materials. Advanced Science, 9(9).
  Lipinski, Gregor; Jeong, Kwanghee; Moritz, Katharina; Petermann, Marcus; May, Eric F.; Stanwix, Paul L. & Richter, Markus