Download or read book Mineral Dissolution Kinetics at the Pore Scale written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Mineral dissolution rates in the field have been reported to be orders of magnitude slower than those measured in the laboratory, an unresolved discrepancy that severely limits our ability to develop scientifically defensible predictive or even interpretive models for many geochemical processes in the earth and environmental sciences. One suggestion links this discrepancy to the role of physical and chemical heterogeneities typically found in subsurface soils and aquifers in producing scale-dependent rates where concentration gradients develop. In this paper, we examine the possibility that scale-dependent mineral dissolution rates can develop even at the single pore and fracture scale, the smallest and most fundamental building block of porous media. To do so, we develop two models to analyze mineral dissolution kinetics at the single pore scale: (1) a Poiseuille Flow model that applies laboratory-measured dissolution kinetics at the pore or fracture wall and couples this to a rigorous treatment of both advective and diffusive transport, and (2) a Well-Mixed Reactor model that assumes complete mixing within the pore, while maintaining the same reactive surface area, average flow rate, and geometry as the Poiseuille Flow model. For a fracture, a 1D Plug Flow Reactor model is considered in addition to quantify the effects of longitudinal versus transverse mixing. The comparison of averaged dissolution rates under various conditions of flow, pore size, and fracture length from the three models is used as a means to quantify the extent to which concentration gradients at the single pore and fracture scale can develop and render rates scale-dependent. Three important minerals that dissolve at widely different rates, calcite, plagioclase, and iron hydroxide, are considered. The modeling indicates that rate discrepancies arise primarily where concentration gradients develop due to comparable rates of reaction and advective transport, and incomplete mixing via molecular diffusion. The magnitude of the reaction rate is important, since it is found that scaling effects (and thus rate discrepancies) are negligible at the single pore and fracture scale for plagioclase and iron hydroxide because of the slow rate at which they dissolve. In the case of calcite, where dissolution rates are rapid, scaling effects can develop at high flow rates from 0.1 cm/s to 1000 cm/s and for fracture lengths less than 1 cm. At more normal flow rates, however, mixing via molecular diffusion is effective in homogenizing the concentration field, thus eliminating any discrepancies between the Poiseuille Flow and the Well-Mixed Reactor model. This suggests that a scale dependence to mineral dissolution rates is unlikely at the single pore or fracture scale under normal geological/hydrologic conditions, implying that the discrepancy between laboratory and field rates must be attributed to other factors.
Download or read book A Pore Scale Evaluation of the Kinetics of Mineral Dissolution and Precipitation Reactions EMSI written by Carl I. Steefel and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The chief goals for CEKA are to (1) collect and synthesize molecular-level kinetic data into a coherent framework that can be used to predict time evolution of environmental processes over a range of temporal and spatial scales; (2) train a cohort of talented and diverse students to work on kinetic problems at multiple scales; (3) develop and promote the use of new experimental techniques in environmental kinetics; (4) develop and promote the use of new modeling tools to conceptualize reaction kinetics in environmental systems; and (5) communicate our understanding of issues related to environmental kinetics and issues of scale to the broader scientific community and to the public.
Download or read book Pore Scale Geochemical Processes written by Carl Steefel and published by Walter de Gruyter GmbH & Co KG. This book was released on 2015-09-25 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt: This RiMG (Reviews in Mineralogy & Geochemistry) volume includes contributions that review experimental, characterization, and modeling advances in our understanding of pore-scale geochemical processes. The volume had its origins in a special theme session at the 2015 Goldschmidt Conference in Prague. From a diversity of pore-scale topics that ranged from multi-scale characterization to modeling, this work summarizes the state-of-the-science in this subject. Topics include: modification of thermodynamics and kinetics in small pores. chemo-mechanical processes and how they affect porosity evolution in geological media. small angle neutron scattering (SANS) techniques. how isotopic gradients across fluid–mineral boundaries can develop and how these provide insight into pore-scale processes. Information on an important class of models referred to as "pore network" and much more. The material in this book is accessible for graduate students, researchers, and professionals in the earth, material, environmental, hydrological, and biological sciences. The pore scale is readily recognizable to geochemists, and yet in the past it has not received a great deal of attention as a distinct scale or environment that is associated with its own set of questions and challenges. Is the pore scale merely an environment in which smaller scale (molecular) processes aggregate, or are there emergent phenomena unique to this scale? Is it simply a finer-grained version of the "continuum" scale that is addressed in larger-scale models and interpretations? The scale is important because it accounts for the pore architecture within which such diverse processes as multi-mineral reaction networks, microbial community interaction, and transport play out, giving rise to new geochemical behavior that might not be understood or predicted by considering smaller or larger scales alone.
Download or read book Pore scale Analysis of Mixing controlled Calcium Carbonate Precipitation and Dissolution Kinetics in Microfluidic Experiments written by and published by . This book was released on 2013 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermodynamics and Kinetics of Water Rock Interaction written by Eric H. Oelkers and published by Walter de Gruyter GmbH & Co KG. This book was released on 2018-12-17 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt: Volume 70 of Reviews in Mineralogy and Geochemistry represents an extensive review of the material presented by the invited speakers at a short course on Thermodynamics and Kinetics of Water-Rock Interaction held prior to the 19th annual V. M. Goldschmidt Conference in Davos, Switzerland (June 19-21, 2009). Contents: Thermodynamic Databases for Water-Rock Interaction Thermodynamics of Solid Solution-Aqueous Solution Systems Mineral Replacement Reactions Thermodynamic Concepts in Modeling Sorption at the Mineral-Water Interface Surface Complexation Modeling: Mineral Fluid Equilbria at the Molecular Scale The Link Between Mineral Dissolution/Precipitation Kinetics and Solution Chemistry Organics in Water-Rock Interactions Mineral Precipitation Kinetics Towards an Integrated Model of Weathering, Climate, and Biospheric Processes Approaches to Modeling Weathered Regolith Fluid-Rock Interaction: A Reactive Transport Approach Geochemical Modeling of Reaction Paths and Geochemical Reaction Networks
Download or read book Kinetics of Water Rock Interaction written by Susan Brantley and published by Springer Science & Business Media. This book was released on 2007-12-29 with total page 843 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geochemical kinetics as a topic is now of importance to a wide range of geochemists in academia, industry, and government, and all geochemists need a rudimentary knowledge of the field. This book summarizes the fundamentals of geochemical kinetics with examples drawn especially from mineral dissolution and precipitation. It also encompasses discussion of high temperature processes and global geochemical cycle modeling. Analysis of textures of rocks, sediments, and mineral surfaces are incorporated throughout and provide a sub-theme of the book.
Download or read book Mineral Dissolution Kinetics New Perspectives written by Victor W Truesdale and published by . This book was released on 2025-04-10 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mineral dissolution kinetics is a critically undervalued field of chemistry. It has helped explain continental weathering and landform development, informed how we maintain water supplies for agricultural and human use, been foundational to our understanding of the formation and operation of the marine environment, and served as an essential tool in the long-term storage of CO2 and radio-nuclide waste. In recent years, mineral dissolution kinetics have also become immensely important in solving the problem of the human-induced rise in tropospheric CO2, a key cause of global warming and ocean acidification.Even though mineral dissolution kinetics has long been a subject of study, unlike the progress made with other chemical systems, its fundamentals are under-developed. Mineral Dissolution Kinetics reveals how the compounding of many otherwise subtle misunderstandings has resulted in this inadequacy. It trawls through a wide cross-section of existing studies to reveal these misunderstandings and forge a new way forward. Complex subjects such as the hydrodynamics of dissolution, the thermodynamics of the aqueous carbonate system, and central omissions at the very core of homogenous kinetics are all explained clearly and simply, while still remaining at the cutting edge of the field.At its core, this book is a search for a universal rate equation for mineral dissolutions. It documents and details the journey which its authors have undertaken, and as such will appeal greatly not only to specialists and experts in all related fields, but also to novice readers seeking to learn more about this unique subject.
Download or read book Description of Input and Examples for Phreeqc Version 3 written by David L. Parkhurst and published by Createspace Independent Publishing Platform. This book was released on 2014-07-17 with total page 518 pages. Available in PDF, EPUB and Kindle. Book excerpt: PHREEQC version 3 is a computer program written in the C and C++ programming languages that is designed to perform a wide variety of aqueous geochemical calculations. PHREEQC implements several types of aqueous models: two ion-association aqueous models (the Lawrence Livermore National Laboratory model and WATEQ4F), a Pitzer specific-ion-interaction aqueous model, and the SIT (Specific ion Interaction Theory) aqueous model. Using any of these aqueous models, PHREEQC has capabilities for (1) speciation and saturation-index calculations; (2) batch-reaction and one-dimensional (1D) transport calculations with reversible and irreversible reactions, which include aqueous, mineral, gas, solid-solution, surface-complexation, and ion-exchange equilibria, and specified mole transfers of reactants, kinetically controlled reactions, mixing of solutions, and pressure and temperature changes; and (3) inverse modeling, which finds sets of mineral and gas mole transfers that account for differences in composition between waters within specified compositional uncertainty limits.
Download or read book Geological Carbon Storage written by Stéphanie Vialle and published by John Wiley & Sons. This book was released on 2018-11-15 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt: Geological Carbon Storage Subsurface Seals and Caprock Integrity Seals and caprocks are an essential component of subsurface hydrogeological systems, guiding the movement and entrapment of hydrocarbon and other fluids. Geological Carbon Storage: Subsurface Seals and Caprock Integrity offers a survey of the wealth of recent scientific work on caprock integrity with a focus on the geological controls of permanent and safe carbon dioxide storage, and the commercial deployment of geological carbon storage. Volume highlights include: Low-permeability rock characterization from the pore scale to the core scale Flow and transport properties of low-permeability rocks Fundamentals of fracture generation, self-healing, and permeability Coupled geochemical, transport and geomechanical processes in caprock Analysis of caprock behavior from natural analogues Geochemical and geophysical monitoring techniques of caprock failure and integrity Potential environmental impacts of carbon dioxide migration on groundwater resources Carbon dioxide leakage mitigation and remediation techniques Geological Carbon Storage: Subsurface Seals and Caprock Integrity is an invaluable resource for geoscientists from academic and research institutions with interests in energy and environment-related problems, as well as professionals in the field.
Download or read book Aqueous Environmental Geochemistry written by Donald Langmuir and published by . This book was released on 1997 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book offers thorough, up-to-date coverage of controls on the chemical quality of surface and subsurface waters, both pristine and polluted, with an emphasis on problem-solving and practical applications. The text is appropriate for courses in aqueous geochemistry or aquatic chemistry. Desirable prerequisites are introductory courses or the equivalent in thermodynamics and solution chemistry, and in physical geology including mineralogy.
Download or read book Pore Scale Phenomena Frontiers In Energy And Environment written by John M Poate and published by World Scientific. This book was released on 2015-04-09 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: The field of pore scale phenomena is now emerging as one of the frontiers of science and many engineering disciplines. Transport phenomena in the subsurface of the earth play key roles in the energy and environmental domains. For example, the shale gas and oil boom is revolutionizing the world's energy portfolio. Pore scale phenomena from the nanoscale to mesoscale dominate the extraction of these resources. Similarly in the environmental domain, pore storage and pore-scale physics affect the availability of water resources and protecting its quality. Water flow and vapor transport in the pores near the land surface is critical to understanding soil water evaporation in the context of local and global hydrologic cycles affecting climate and climate change.Pore scale phenomena similarly play critical roles in the domain of materials science and biology. For example, many energy devices and membrane technologies are controlled by the physical and chemical properties of the pores. Identifying and analyzing the properties of these pores has emerged as a frontier of characterization science.This book provides, for the first time, a comprehensive overview of the fascinating interrelationship between engineering and science. The authors and contributors are recognized experts from the faculty of the Colorado School of Mines, Northwestern and Stanford. This book will appeal to earth and environmental scientists, materials scientists, physicists and chemists.
Download or read book Geochemistry Groundwater and Pollution written by C.A.J. Appelo and published by CRC Press. This book was released on 2004-06-24 with total page 678 pages. Available in PDF, EPUB and Kindle. Book excerpt: Building on the success of its 1993 predecessor, this second edition of Geochemistry, Groundwater and Pollution has been thoroughly re-written, updated and extended to provide a complete and authoritative account of modern hydrogeochemistry.Offering a quantitative approach to the study of groundwater quality and the interaction of water, minerals,
Download or read book Pore scale Microstructure Mechanisms and Models for Subsurface Flow and Transport written by James E. McClure and published by Frontiers Media SA. This book was released on 2022-11-29 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Negative Emissions Technologies and Reliable Sequestration written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2019-04-08 with total page 511 pages. Available in PDF, EPUB and Kindle. Book excerpt: To achieve goals for climate and economic growth, "negative emissions technologies" (NETs) that remove and sequester carbon dioxide from the air will need to play a significant role in mitigating climate change. Unlike carbon capture and storage technologies that remove carbon dioxide emissions directly from large point sources such as coal power plants, NETs remove carbon dioxide directly from the atmosphere or enhance natural carbon sinks. Storing the carbon dioxide from NETs has the same impact on the atmosphere and climate as simultaneously preventing an equal amount of carbon dioxide from being emitted. Recent analyses found that deploying NETs may be less expensive and less disruptive than reducing some emissions, such as a substantial portion of agricultural and land-use emissions and some transportation emissions. In 2015, the National Academies published Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration, which described and initially assessed NETs and sequestration technologies. This report acknowledged the relative paucity of research on NETs and recommended development of a research agenda that covers all aspects of NETs from fundamental science to full-scale deployment. To address this need, Negative Emissions Technologies and Reliable Sequestration: A Research Agenda assesses the benefits, risks, and "sustainable scale potential" for NETs and sequestration. This report also defines the essential components of a research and development program, including its estimated costs and potential impact.
Download or read book A Novel Approach to Experimental Studies of Mineral Dissolution Kinetics written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Currently, DOE is conducting pilot CO2 injection tests to evaluate the concept of geological sequestration. The injected CO2 is expected to react with the host rocks and these reactions can potentially alter the porosity, permeability, and mechanical properties of the host or cap rocks. Reactions can also result in precipitation of carbonate-containing minerals that favorably and permanently trap CO2 underground. Many numerical models have been used to predict these reactions for the carbon sequestration program. However, a firm experimental basis for predicting silicate reaction kinetics in CO2 injected geological formations is urgently needed to assure the reliability of the geochemical models used for the assessments of carbon sequestration strategies. The funded experimental and theoretical study attempts to resolve this outstanding scientific issue by novel experimental design and theoretical interpretation of silicate dissolution rates at conditions pertinent to geological carbon sequestration. In this four year research grant (three years plus a one year no cost extension), seven (7) laboratory experiments of CO2-rock-water interactions were carried out. An experimental design allowed the collection of water samples during experiments in situ and thus prevented back reactions. Analysis of the in situ samples delineated the temporal evolution of aqueous chemistry because of CO2-rock-water interactions. The solid products of the experiments were retrieved at the end of the experimental run, and analyzed with a suite of advanced analytical and electron microscopic techniques (i.e., atomic resolution transmission electron microscopy (TEM), scanning electron microscopy (SEM), electron microprobe, X-ray diffraction, X-ray photoelectron spectroscopy (XPS)). As a result, the research project probably has produced one of the best data sets for CO2-rock-water interactions in terms of both aqueous solution chemistry and solid characterization. Three experiments were performed using the Navajo sandstone. Navajo sandstone is geologically equivalent to the Nugget sandstone, which is a target formation for a regional partnership injection project. Our experiments provided the experimental data on the potential CO2-rock-water interactions that are likely to occur in the aquifer. Geochemical modeling was performed to interpret the experimental results. Our single mineral (feldspar) experiments addressed a basic research need. i.e., the coupled nature of dissolution and precipitation reactions, which has universal implication to the reaction kinetics as it applied to CO2 sequestration. Our whole rock experiments (Navajo sandstone) addressed the applied research component, e.g., reacting Navajo sandstone with brine and CO2 has direct relevance on the activities of a number of regional partnerships. The following are the major findings from this project: (1) The project generated a large amount of experimental data that is central to evaluating CO2-water-rock interactions and providing ground truth to predictive models, which have been used and will inevitably be increasingly more used in carbon sequestration. (2) Results from the feldspar experiments demonstrated stronger coupling between dissolution and precipitation reactions. We show that the partial equilibrium assumption did not hold in the feldspar hydrolysis experiments (Zhu and Lu, submitted, Appendix A-2). The precipitation of clay minerals influenced dissolution of primary silicate in a much stronger way as previously envisioned. Therefore, our experimental data indicated a much more complex chemical kinetics as it has been applied to carbon sequestration program in terms of preliminary predictive models of CO2-rock-water interactions. Adopting this complexity (strong coupling) may influence estimates of mineral trapping and porosity/permeability for geological carbon sequestration. In general, our knowledge of the coupling of different reactions is poor, and we must consider the uncertainties resulting from our poor knowledge on this regard. (3) Our experimental results concur with previous findings that the role of dissolved CO2 is mostly to acidify the brine, but not change the mechanisms of reactions. This conclusion is based on careful paired experiments with and without CO2. (4) We observed strong chemical reactions between CO2 acidified brine with the Navajo sandstone. The laboratory experiments were conducted at a higher temperature (200 C) than that in the field ((almost equal to)90 C) in order to induce measurable chemical changes in the laboratory. However, field conditions are more acidic and reaction time is much longer (1000 years versus 10-80 days in the laboratory). Therefore, the conclusions on extensive reactions are relevant. We observed extensive dissolution of feldspars, and precipitation of clay minerals.
Download or read book Non Fickian Solute Transport written by William Taylor and published by . This book was released on 2015-02-12 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research-based book provides a mathematical approach based on stochastic calculus which describes state-of-the-art information regarding porous media science and engineering - prediction of dispersivity from covariance of hydraulic conductivity (velocity). The complication is of great significance for tracer examination, for improved recovery by injection of miscible gases, etc. The book elucidates a generalized mathematical model and efficient numerical methodologies that may greatly affect the stochastic porous media hydrodynamics. It begins with a descriptive basic analysis of the complication of scale dependence of the dispersion coefficient in porous media. Furthermore, relevant topics of stochastic calculus which would be helpful in modeling are discussed subsequently. An in-depth elaborative discussion regarding the development of a generalized stochastic solute transport model for any provided velocity covariance without conferring to fickian expectations from laboratory scale to field scale is also illustrated in this book. The mathematical approaches described in this book will serve as useful solutions for several other complications associated with chemical dispersion in porous media.
Download or read book Mineral Scale Formation and Inhibition written by Z. Amjad and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 356 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book documents the proceedings of the symposium, "Mineral Scale Formation and Inhibition," held at the American Chemical Society Annual Meeting August 21 to 26, 1994, in Washington, D. C. The symposium, sponsored by the Division of Colloid and Surface Chemistry, was held in honor of Professor George H. Nancollas for his pioneering work in the field of crystal growth from solution. A total of 30 papers were presented by a wide spectrum of scientists. This book also includes papers that were not presented but were in the symposium program. The separation of a solid by crystallization is one of the oldest and perhaps the most frequently used operations in chemistry. Because of its widespread applicability, in recent years there has been considerable interest exhibited by academic and industrial scientists in understanding the mechanisms of crystallization of sparingly soluble salts. The salt systems of great interest in industrial water treatment area (i. e. , cooling and boiler) include carbon ates, sulfates, phosphates, and phosphonates of alkaline earth metals. Although not as common as calcium carbonate and calcium sulfate, barium and strontium sulfates have long plagued oil field and gas production operations. The build-up of these sparingly soluble salts on equipment surfaces results in lower heat transfer efficiency, increased corrosion rates, increased pumping costs, etc. In the laundry application, insoluble calcium carbonate tends to accumulate on washed fabrics and washing equipment parts, resulting in undesirable fabric-encrustation or scaling.
