{"title":"A generalized kinetic theory of Ostwald ripening in porous media","authors":"Nicolas Bueno, Luis Ayala, Yashar Mehmani","doi":"10.1016/j.advwatres.2024.104826","DOIUrl":null,"url":null,"abstract":"<div><div>Partially miscible bubbles (e.g., CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>) trapped inside a porous medium and surrounded by a wetting phase (e.g., water) occur in a number of applications including underground hydrogen storage, geologic carbon sequestration, and the operation of electrochemcial devices such as fuel cells and electrolyzers. Such bubbles evolve due to a process called Ostwald ripening that is driven by differences in their interfacial curvature. For spherical bubbles, small bubbles shrink and vanish while feeding into larger ones, resulting in one large bubble at equilibrium. Within the confinement of a porous medium, however, bubbles can attain a distribution of sizes at equilibrium that have identical curvature. This work concerns itself with the formulation of a kinetic theory that predicts the statistical evolution of bubble <em>states</em>, defined as the sizes of the pores within which bubbles are trapped and the extent to which those pores are saturated with bubbles. The theory consists of a population balance equation and appropriate closure approximations. Systematic comparisons against a previously published pore network model (PNM) are conducted to validate the theory. Our theory generalizes existing variants in the literature limited to spherical bubbles trapped in homogeneous media to non-spherical (deformed) bubbles inside microstructures with arbitrary heterogeneity and spatial correlation in pore/throat sizes. We discuss the applicability, limitations, and implications of the theory towards future extensions.</div></div>","PeriodicalId":7614,"journal":{"name":"Advances in Water Resources","volume":"193 ","pages":"Article 104826"},"PeriodicalIF":4.0000,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advances in Water Resources","FirstCategoryId":"93","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0309170824002136","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"WATER RESOURCES","Score":null,"Total":0}
引用次数: 0
Abstract
Partially miscible bubbles (e.g., CO) trapped inside a porous medium and surrounded by a wetting phase (e.g., water) occur in a number of applications including underground hydrogen storage, geologic carbon sequestration, and the operation of electrochemcial devices such as fuel cells and electrolyzers. Such bubbles evolve due to a process called Ostwald ripening that is driven by differences in their interfacial curvature. For spherical bubbles, small bubbles shrink and vanish while feeding into larger ones, resulting in one large bubble at equilibrium. Within the confinement of a porous medium, however, bubbles can attain a distribution of sizes at equilibrium that have identical curvature. This work concerns itself with the formulation of a kinetic theory that predicts the statistical evolution of bubble states, defined as the sizes of the pores within which bubbles are trapped and the extent to which those pores are saturated with bubbles. The theory consists of a population balance equation and appropriate closure approximations. Systematic comparisons against a previously published pore network model (PNM) are conducted to validate the theory. Our theory generalizes existing variants in the literature limited to spherical bubbles trapped in homogeneous media to non-spherical (deformed) bubbles inside microstructures with arbitrary heterogeneity and spatial correlation in pore/throat sizes. We discuss the applicability, limitations, and implications of the theory towards future extensions.
期刊介绍:
Advances in Water Resources provides a forum for the presentation of fundamental scientific advances in the understanding of water resources systems. The scope of Advances in Water Resources includes any combination of theoretical, computational, and experimental approaches used to advance fundamental understanding of surface or subsurface water resources systems or the interaction of these systems with the atmosphere, geosphere, biosphere, and human societies. Manuscripts involving case studies that do not attempt to reach broader conclusions, research on engineering design, applied hydraulics, or water quality and treatment, as well as applications of existing knowledge that do not advance fundamental understanding of hydrological processes, are not appropriate for Advances in Water Resources.
Examples of appropriate topical areas that will be considered include the following:
• Surface and subsurface hydrology
• Hydrometeorology
• Environmental fluid dynamics
• Ecohydrology and ecohydrodynamics
• Multiphase transport phenomena in porous media
• Fluid flow and species transport and reaction processes