{"title":"Capillarity-Driven Hydrate Film Formation in Geologic Carbon Storage","authors":"David E. Fukuyama, Hugh C. Daigle, Wen Song","doi":"10.1007/s11242-024-02062-3","DOIUrl":null,"url":null,"abstract":"<div><p>Much of the continental margins in the world oceans provide the necessary thermodynamic conditions to store CO<span>\\(_2\\)</span> as ice-like hydrates (CO<span>\\(_2\\cdot\\)</span>6 H<span>\\(_2\\)</span>O). While resistant to buoyant migration and leakage, the fundamental growth mechanisms that control the injection, capacity, and security of CO<span>\\(_2\\)</span> hydrates stored in the seafloor remain unresolved. Extensive field and laboratory testing give rise to conflicting views on the kinetics and growth configurations of hydrates, where mechanistic models reconciling the formation of hydrates observed in nature remain missing. This work elucidates a fundamental pore-scale reactive transport mechanism that underpins the rate and morphology of hydrate formation. We reveal a previously unrecognized mode of hydrate formation in porous seafloor sediments, hydrate film growth via reaction-imbibition, where superhydrophilic hydrate crystallites (<span>\\(\\theta \\sim 0^\\circ\\)</span>) formed at water–CO<span>\\(_2\\)</span> interfaces create a secondary microporous medium (<span>\\(\\sim\\)</span> 10 to 100 nm pores) within lithologic sediment pores (<span>\\(\\sim\\)</span> 10 to 100 <span>\\(\\mu\\)</span>m pores) to promote further hydrate growth. Unlike past diffusion-controlled models, we show that spontaneous water imbibition into the hydrate micropores establishes rapidly new water–CO<span>\\(_2\\)</span> interfaces (i.e., hydrate formation surfaces) via capillary-driven convection and is the dominant mechanism for supplying water to the hydrate formation interface.</p></div>","PeriodicalId":804,"journal":{"name":"Transport in Porous Media","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Transport in Porous Media","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s11242-024-02062-3","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, CHEMICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Much of the continental margins in the world oceans provide the necessary thermodynamic conditions to store CO\(_2\) as ice-like hydrates (CO\(_2\cdot\)6 H\(_2\)O). While resistant to buoyant migration and leakage, the fundamental growth mechanisms that control the injection, capacity, and security of CO\(_2\) hydrates stored in the seafloor remain unresolved. Extensive field and laboratory testing give rise to conflicting views on the kinetics and growth configurations of hydrates, where mechanistic models reconciling the formation of hydrates observed in nature remain missing. This work elucidates a fundamental pore-scale reactive transport mechanism that underpins the rate and morphology of hydrate formation. We reveal a previously unrecognized mode of hydrate formation in porous seafloor sediments, hydrate film growth via reaction-imbibition, where superhydrophilic hydrate crystallites (\(\theta \sim 0^\circ\)) formed at water–CO\(_2\) interfaces create a secondary microporous medium (\(\sim\) 10 to 100 nm pores) within lithologic sediment pores (\(\sim\) 10 to 100 \(\mu\)m pores) to promote further hydrate growth. Unlike past diffusion-controlled models, we show that spontaneous water imbibition into the hydrate micropores establishes rapidly new water–CO\(_2\) interfaces (i.e., hydrate formation surfaces) via capillary-driven convection and is the dominant mechanism for supplying water to the hydrate formation interface.
摘要 世界海洋中的大部分大陆边缘提供了必要的热力学条件,将 CO (_2)储存为冰状水合物(CO (_2) 6 H (_2) O)。虽然可以抵抗浮力迁移和泄漏,但控制海底储存的 CO (_2)水合物的注入、容量和安全性的基本生长机制仍未解决。广泛的现场和实验室测试导致人们对水合物的动力学和生长构型产生了相互冲突的观点,其中仍然缺少可协调自然界中观察到的水合物形成的机理模型。这项研究阐明了一种基本的孔隙尺度反应传输机制,它是水合物形成速率和形态的基础。我们揭示了一种以前未曾认识到的多孔海底沉积物中的水合物形成模式,即通过反应-吸附作用形成水合物膜、其中,在水-CO(_2)界面形成的超亲水性水合物结晶(10-100 nm 孔隙)在岩性沉积物孔隙(10-100 m 孔隙)内形成次生微孔介质(10-100 nm 孔隙),以促进水合物的进一步生长。与过去的扩散控制模型不同,我们的研究表明,自发渗入水合物微孔的水通过毛细管驱动的对流迅速建立了新的水-CO(_2)界面(即水合物形成面),并且是向水合物形成界面供水的主要机制。
期刊介绍:
-Publishes original research on physical, chemical, and biological aspects of transport in porous media-
Papers on porous media research may originate in various areas of physics, chemistry, biology, natural or materials science, and engineering (chemical, civil, agricultural, petroleum, environmental, electrical, and mechanical engineering)-
Emphasizes theory, (numerical) modelling, laboratory work, and non-routine applications-
Publishes work of a fundamental nature, of interest to a wide readership, that provides novel insight into porous media processes-
Expanded in 2007 from 12 to 15 issues per year.
Transport in Porous Media publishes original research on physical and chemical aspects of transport phenomena in rigid and deformable porous media. These phenomena, occurring in single and multiphase flow in porous domains, can be governed by extensive quantities such as mass of a fluid phase, mass of component of a phase, momentum, or energy. Moreover, porous medium deformations can be induced by the transport phenomena, by chemical and electro-chemical activities such as swelling, or by external loading through forces and displacements. These porous media phenomena may be studied by researchers from various areas of physics, chemistry, biology, natural or materials science, and engineering (chemical, civil, agricultural, petroleum, environmental, electrical, and mechanical engineering).