248th ACS National Meeting
San Francisco, CA: March 10-14, 2014
In spite of the ongoing debate, Carbon Capture and Sequestration (CCS) still remains the most viable solution for carbon management. The interfacial behavior and reactivity in supercritical CO2 with the various components of a sequestration system can be dramatically different than in aqueous media. Partitioning of ions, water, hydrocarbons or organic contaminants have significant impact on the interaction of the supercritical fluid with mineral, metal and other surfaces comprising the sequestration system. At the core of our effort to improve CO2 mitigation strategies is the demand for a more comprehensive understanding of the underlying mechanistic steps controlling the fate of these components, while bridging over to macroscopic observations. Recent advances in computer architectures, algorithms and instrumentation have enabled unique synergy between theory and experiment. Theoretical efforts benefiting from efficient sampling techniques, or effective use of intuitive, smaller scale models combined with innovative in-situ experimental measurements can provide meaningful insights into these complex geochemical problems. Therefore, we invite theoretical and experimental papers, and in particular those combining both, that highlight geochemical issues related to CCS and the reactivity of supercritical fluids in sequestration systems.
This is a general session for the Geochemistry Division. This session accepts both oral and poster contributions, including posters for the SCI-MIX session.
Fine scale porosity in rocks and soils is the primary locus for fluid-solid interaction, storage and separation of fluids, weathering, and dissolution and precipitation reactions. Fluid density, composition, phase state and nano-structure change in narrow pores due to the combined effects of adsorption and geometric confinement. Quantification and understanding of fluid behavior in these environments is important for optimization of large-scale geologic engineering processes such as natural gas and oil extraction from (un)conventional reservoirs and geologic carbon storage. Using modern experimental techniques, theory, and simulation tools, nanoscale properties of geochemical systems are studied with the goal of developing capabilities to predict rates of geochemical processes at the nanoscale to aid in upscaling and reservoir modeling.
This symposium will focus on new techniques that help elucidate geochemical processes at nanometer to micron scales. We invite paper submissions that highlight geochemical issues associated with rock characterization and rock reactivity as well as solid-fluid interactions.
Clayey materials are used as barriers for the isolation of landfills and contaminated sites and are envisioned as long-term storage media for hazardous materials and radioactive wastes. In the case of geological CO2 sequestration or energy storage, clayey formations serve as seals whose properties greatly influence the integrity, efficiency and safety of these applications. These applications rely on the low permeability, high adsorption capacity, and strong water-affinity of clayey media. In the last decade, clay science has been the subject of intensive research. Efforts on the properties of clays and clay minerals aimed at gaining confidence in long-term predictions of the evolution of geological storage/sequestration systems. The understanding of clay minerals properties has increased significantly, in particular as a result of advances in coupling scales ranging from the molecular level to the geological formation scale. The proposed session aims at gathering colleagues interested in recent breakthroughs and challenges that remain to understand the fundamental properties of clay materials and the manner in which these properties affect the engineering applications of natural and engineered clay barriers.
The mechanisms, kinetics and thermodynamics of solid-state transformations in geochemistry are poorly understood at the molecular scale, much less so than even precipitation/dissolution processes. Both theoretical and experimental contributions to this symposium are welcome. Topics may include, but are not limited to, transformations driven by (1) redox processes, (2) chemical potential of species in the environment such as oxygen, water, and CO2 and their diffusion into or out of the mineral, (3) temperature, and (4) pressure. Of special interest are theoretical and experimental methods, particularly in situ techniques, capable of investigating the mechanisms of transformation at the atomic level in a complex environment.
Incorporation into mineral phases has important implications for the subsurface transport of radionuclides and in-situ technologies used to remediate nuclear-contaminated sites. We invite papers summarizing experimental and/or computational studies of the processes that lead to the uptake and incorporation of radionuclides in mineral phases as well as studies that consider the structure and reactivity of radionuclide-bearing phases.