Nanothermodynamics and Molecular Simulations of Fluids in Porous Media
Doctoral thesis
Permanent lenke
https://hdl.handle.net/11250/2994442Utgivelsesdato
2022Metadata
Vis full innførselSamlinger
- Institutt for kjemi [1397]
Sammendrag
The thermodynamic and transport properties of fluids confined to porous media are in this thesis investigated with nanothermodynamics, non-equilibrium thermodynamics, and molecular simulations. Non-equilibrium thermodynamics is applied to describe the non-isothermal transport of a two-phase fluid in a representative elementary volume (REV) of a porous medium. The thermodynamic variables of the REV are defined, and the entropy production and flux-force equations are derived. The thermodynamic variables of the REV are constructed from additive contributions, namely from the bulks phases, surfaces, and three-phase contact lines. There are three driving forces present, the thermal force, a chemical force, and a pressure force. For nanoporous systems, we found that we need to introduce the integral pressure. The integral pressure is a concept from nanothermodynamics and is different from the differential pressure, which is the normal pressure. We realized with this work, that to calculate the driving force in non-equilibrium conditions, namely the pressure gradient, we first needed to compose a procedure to calculate the pressure of a porous medium. We calculated the thermodynamic properties of fluids in nanoporous media using nanothermodynamics. The thermodynamic properties we calculated were for example the integral pressure, surface tension, entropy, and disjoining pressure. We calculated the transport coefficients of a single-phase fluid in a fcc lattice of solid spheres. We assumed that the integral pressure is constant when the system is in equilibrium and used this to calculate the integral pressure in a bulk fluid in equilibrium with the porous media. From this, we constructed an equation of state which relates the fluid density of the porous medium, temperature, and porosity to the integral pressure. The gradient in integral pressure is the driving force for fluid flow. Together with the mass flux and shear viscosity, we calculated the hydraulic conductivity and permeability of the system.
Består av
Article 1: Kjelstrup, Signe; Bedeaux, Dick; Hansen, Alex; Hafskjold, Bjørn; Galteland, Olav. Non-isothermal transport of multi-phase fluids in porous media. The entropy production. Frontiers in Physics 2018 ;Volum 6. s. 1-14 https://doi.org/10.3389/fphy.2018.00126 This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)Article 2: Kjelstrup, Signe; Bedeaux, Dick; Hansen, Alex; Hafskjold, Bjørn; Galteland, Olav. Non-isothermal Transport of Multi-phase Fluids in Porous Media. Constitutive Equations. Frontiers of Physics 2019 ;Volum 6. s. 1-12 https://doi.org/10.3389/fphy.2018.00150 This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
Article 3: Galteland, Olav; Bedeaux, Dick; Hafskjold, Bjørn; Kjelstrup, Signe. Pressures Inside a Nano-Porous Medium. The Case of a Single Phase Fluid. Frontiers in Physics 2019 ;Volum 7 https://doi.org/10.3389/fphy.2019.00060 This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY)
Article 4: Erdős, Máté; Galteland, Olav; Bedeaux, Dick; Kjelstrup, Signe; Moultos, Othonas A.; Vlugt, Thijs J.H.. Gibbs ensemble Monte Carlo simulation of fluids in confinement: Relation between the differential and integral pressures. Nanomaterials 2020 ;Volum 10.(293) s. 1-12 ; https://doi.org/10.3390/nano10020293 This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).
Article 5: Rauter, Michael Tobias; Galteland, Olav; Erdos, Mate; Moultos, Othonas A.; Vlugt, Thijs J.H.; Schnell, Sondre Kvalvåg; Bedeaux, Dick; Kjelstrup, Signe. Two-Phase Equilibrium Conditions in Nanopores. Nanomaterials 2020 ;Volum 10.(4) https://doi.org/10.3390/nano10040608 This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).
Article 6: Galteland, Olav; Bedeaux, Dick; Kjelstrup, Signe. Nanothermodynamic Description and Molecular Simulation of a Single-Phase Fluid in a Slit Pore. Nanomaterials 2021 ;Volum 11.(165) https://doi.org/10.3390/nano11010165 This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).
Article 7: Galteland, Olav; Bering, Eivind; Kristiansen, Kim; Bedeaux, Dick; Kjelstrup, Signe Helene. Legendre-Fenchel transforms capture layering transitions in porous media. arXiv.org 2021 https://arxiv.org/abs/2111.15253
Article 8: Galteland, Olav; Rauter, Michael Tobias; Varughese, Kevin K.; Bedeaux, Dick; Kjelstrup, Signe Helene. Defining the pressures of a fluid in a nanoporous, heterogeneous medium. arXiv.org 2022 https://arxiv.org/abs/2201.13060
Article 9: Galteland, Olav; Rauter, Michael Tobias; Bratvold, Mina S.; Trinh, Thuat; Bedeaux, Dick; Kjelstrup, Signe. Local thermodynamic description of isothermal single-phase flow in porous media. arXiv.org 2022 https://arxiv.org/abs/2203.02334