Water in minerals? A peak in the infrared

The study of water in minerals with infrared spectroscopy is reviewed with emphasis on natural and synthetic quartz. Water can be recognized in minerals as fluid inclusions and as isolated molecules and can be distinguished from hydroxide ion. The distinction between very small inclusions and aggregates of structurally bound molecules is difficult. New studies of synthetic quartz using near-infrared spectroscopy are reported. These demonstrate that water molecules are the dominant hydrogen containing species in synthetic quartz but that this water is not in aggregates large enough to form ice when cooled

The Transition of CCS from Fossil Fuel CO2 Control to Negative Emissions

The last decade’s major investments in CCUS as a fossil fuel control technology have brought the field to the point that it is effective and readily designed. However even more rapid development of renewable technology is likely to keep CCUS from being a major player in world electric generation as investment in clean electricity from wind and solar is more cost effective and lower risk. However, at least 25% of the ultimate reductions in carbon emissions, and then any required atmospheric remediation through negative emissions, will require those same technologies in slightly different approaches. Much smaller scale capture plants will be required for industrial emissions and for biofuel plants. Fortunately a number of industrial players are already developing technology at this scale. The development of low carbon fuel standards is a huge innovation driver in this space. California regulations will, in the future, permit carbon capture on biofuels to be included in carbon footprint calculations. That market is designed to maintain a price of $100/ton for CO2, and current prices hover around that point. This confluence of new small carbon capture technology and innovative means for providers to get paid for capture will create a new generation of carbon capture, and ultimately negative emissions technologies. Challenges include CO2 transportation and underground storage when the sources are smaller than today’s power plant plans. This talk will focus on the US market for small scale-capture driven by biofuel production, and the approaches that carbon capture providers are taking to make their technology appropriate at this scale

Trace Hydrogen in Minerals

Trace hydrogen in minerals most frequently occurs bonded to oxygen. The resulting water and hydroxyl (OH-) affect and play a role in a variety of mineral properties and reactions. This thesis examines the occurrence of trace hydrogen in nominally anhydrous minerals, the mechanisms by which trace hydrogen participates in reactions and controls properties, and the changes that occur in hydrogen speciation and siting as a function of temperature. The principal tool used in this study is infrared (IR) spectroscopy because of its sensitivity to the highly polar O-H bond, yielding quantitative information on concentration, and symmetry, speciation, and siting information. The speciation of trace hydrogen in garnet and low temperature natural and synthetic quartz is examined in detail. In garnet hydrogen occurs as the hydrogarnet substitution, four hydroxyl groups replacing a silicate tetrahedron. This substitution is extremely common among natural garnets. Concentrations range from 0.05 to 0.20 wt. % (as H2O) in garnets from most occurrences, including garnets from the mantle. This trace hydrogen is truly dissolved. The hydrogen found in natural and synthetic quartz formed at low temperature can occur as either hydroxyl or molecular water. The molecular water is the active participant in hydrolytic weakening of quartz, but it is not truly dissolved. It occurs as small groups of molecules (approximately 5 to 200) which were trapped during rapid growth. Two properties of minerals affected by trace hydrogen are strength and radiation response. Molecular water may be responsible for weakening of other minerals as well as quartz. Both water and hydroxyl participate in radiation response of minerals. In metamict zircon, water stabilizes local charge imbalance formed when bonds are broken. Water enters the crystal after a threshold of damage occurs, and reacts with broken bonds to form hydroxyl groups. These must reform molecular water and be expelled before recrystallization occurs during heating. In quartz, molecular water is strongly correlated with the formation of citrine color during irradiation, but inhibits the formation of the amethyst color center Fe4+. Apparently molecular hydrogen forms during radiolysis of the water, and reduces the Fe4+. Several hydroxyl sites in topaz are strongly correlated with the formation of brown color upon irradiation. The unifying theme in all these reactions is the extreme mobility of hydrogen and the ease with which different oxygen-hydrogen species may be formed in silicates. The behavior of trace hydrogen at temperatures of geologic interest has been examined using high temperature infrared spectroscopy. Direct observations of speciation, concentration, and properties have been made up to 1200°C. In muscovite there is no change in hydrogen speciation or site up to the dehydration point, as expected. However, in cordierite and beryl water reversibly partitions into a gas-like state above 400°C, and the formation of this new state controls the dehydration behavior. In topaz, hydroxyl groups have been observed converting to new sites at temperatures above 500°C. In orthoclase feldspar, one type of molecular water dehydrates at 200°C, while a second type converts irreversibly to a new hydrous species above 600°C. There is no evidence for the existence of hydrogen species other than hydroxyl and water in silicate minerals. The hydrogarnet substitution (four hydroxyl groups in a tetrahedral configuration) is common in garnets and may be important in other orthosilicates. The most common hydrous species in nominally anhydrous silicates (aside from fluid inclusions and alteration) are: small groups of trapped water molecules; individual water molecules occupying voids in the structure of minerals; hydroxyl occurring in a charge balancing role such as AlO3OH substituting for SiO4; hydroxyl neutralizing substitutional atoms, e.g., LiOH; and hydroxyl groups formed from the reaction of broken bonds with water as in radiation damaged minerals. There is no evidence for the presence of the oxonium ion, H3O+, in common minerals, and the existing evidence for the occurrence of molecular hydrogen may better be explained by the presence of water or hydroxyl groups.</p

Fresh water generation from aquifer-pressured carbon storage: Feasibility of treating saline formation waters

AbstractBrines up to 85,000 ppm total dissolved solids produced during Carbon Capture and Storage (CCS) operations in saline formations may be used as the feedstock for desalination and water treatment technologies via reverse osmosis (RO). The aquifer pressure resulting from the injection of carbon dioxide can provide all or part of the inlet pressure for the desalination system. Residual brine from such a process could be reinjected into the formation at net volume reduction, such that the volume of fresh water extracted is comparable to the volume of CO2 injected into the formation. Such a process could provide additional CO2 storage capacity in the aquifer, reduce operational risks (e.g., fracturing, seismicity, leaking) by relieving overpressure in the formation, and provide a source of low-cost fresh water to offset costs or operational water needs equal to about half the water usage of a typical coal ICGG power plant. We call the combined processes of brine removal, treatment, and pressure management active reservoir management. We have examined a range of saline formation water compositions propose a general categorization for the feasibility of the process based total dissolved solids (TDS): •10,000–40,000 mg/L TDS: Standard RO with ≥50% recovery•40,000–85,000 mg/L TDS: Standard RO with ≥10% recovery; higher recovery possible using 1500 psi RO membranes and/or multi-stage incremental desalination likely including NF (nanofiltration)•85,000–300,000 mg/L TDS: Multi-stage process using process design that may differ significantly from seawater systems•>300,000 mg/L TDS brines: Not likely to be treatable Brines in the 10,000–85,000 mg/L TDS range appear to be abundant (geographically and with depth) and could be targeted in planning CCS operations. Costs for desalination of fluids from saline aquifers are in the range of $400–1000/acre foot of permeate when storage aquifer pressures exceed 1200 psi. This is about half of conventional seawater desalination costs of$1000–1400/acre foot. Costs increase by 30 to 50% when pressure must be added at the surface. The primary reason for the cost reduction in pressurized aquifers relative to seawater is the lack of need for energy to drive the high-pressure pumps. An additional cost savings has to do with less pre-treatment than is customary for ocean waters full of biological activity and their degradation products. An innovative parallel low-recovery approach is proposed that would be particularly effective for saline formation waters in the 40,000–85,000 mg/L TDS range

Geologic CO2 storage using pre-injection brine production in tandem reservoirs: A strategy for improved storage performance and enhanced water recovery

Deployment barriers for CO2 capture, utilization, and storage (CCUS) in saline reservoirs can be grouped under three categories: (1) net cost (after accounting for utilization benefits); (2) water intensity of CO2 capture, and (3) uncertainty about storage capacity and permanence. The third category is often considered to be the most challenging. Overpressure, which is fluid pressure that exceeds the original reservoir pressure due to CO2 injection, is the limiting metric for storage capacity and permanence because it drives key physical risks: induced seismicity, caprock fracture, and CO2 leakage. Variables that control overpressure include: (1) the quantity of CO2 and the rate at which it is injected, (2) the size of the reservoir storage compartment, and (3) reservoir permeability. Geologic surveys, geologic logs, and core data from exploration wells provide information that can be used to estimate the size and permeability of the reservoir compartment, but large uncertainties will only be narrowed after there is operational experience with moving large quantities of fluid to move into and/or out of the reservoir. Unlike CCUS applied to CO2 Enhanced Oil Recovery (CO2-EOR) in mature oil fields, CCUS in a saline reservoir will typically (a) have less geologic information and little or no production and injection history to estimate how much CO2 can be safely and permanently stored and (b) not have the advantage of depleted reservoir pressure prior to CO2 injection. Numerous studies have evaluated strategies for managing CO2 storage reservoirs by producing brine to reduce the pressure buildup due to CO2 injection. Most of these studies assume that separate injection and production wells will be used and that brine production will begin during or after the CO2 injection phase. We present a strategy where brine production begins prior to the CO2 injection phase, using the wells that will subsequently be used for CO2 injection. In this strategy, all wells are initially used for exploration and monitoring and then to produce brine prior to injecting CO2. Our strategy also includes the option of using reservoirs in tandem, including: CO2-storage reservoirs: due to their high seal integrity, these are preferred for CO2 storage. Brine produced from these reservoirs may or may not be directly used for water generation. Brine-storage reservoirs: these are used to store brine and/or residual brine and, with treatable brine composition, to produce brine for water generation. For zero net injection, high seal integrity is not required. This strategy has several advantages. First, pressure drawdown observed during brine production mirrors the pressure buildup during CO2 injection, providing necessary data to directly estimate reservoir storage capacity before any CO2 is injected. Second, pressure drawdown is greatest where CO2 will be injected, which is more efficient both on a per well basis and per mass of removed brine basis. Pre-injection brine production in saline reservoirs shares two key advantages of CO2-EOR: (a) greater knowledge about reservoir properties and storage capacity and (b) depleted reservoir pressure, which increases storage capacity. A third advantage is that the flexibility of our tandem-reservoir approach can be used to improve the economics of Enhanced Water Recovery (EWR). The primary metric for selecting a brine-storage reservoir is for its brine composition to be more amenable for treatment for beneficial uses, such as saline cooling water or water generated through desalination. Where applicable, EWR will reduce the water intensity of CCUS, which is particularly valuable in water-stressed regions. For a range of tandem-reservoir scenarios, we assess the influence of CO2-storage and brine-storage reservoir properties (e.g., reservoir compartment size, seal permeability, and salinity) on reservoir pressure management and EWR. We also illustrate how pre-injection brine production can be used as a tool for site selection and characterization, including assessments of CO2 storage capacity and permanence. This work was sponsored by the USDOE Fossil Energy, National Energy Technology Laboratory, managed by Traci Rodosta and Andrea McNemar. This work was performed under the auspices of the USDOE by LLNL under contract DE-AC52-07NA27344

Quantifying the potential exposure hazard due to energetic releases of CO2 from a failed sequestration well

AbstractWells are designed to bring fluids from depth to the earth’s surface quickly. As such they are the most likely pathway for CO2 to return to the surface in large quantities and present a hazard without adequate management. We surveyed oil industry experience of CO2 well failures, and separately, calculated the maximal CO2 flow rate from a 5000 ft depth supercritical CO2 reservoir. The calculated maximum of 20,000 tonne/day was set by the sound speed and the seven-inch well casing diameter, and was greater than any observed event. We used this flux to simulate atmospheric releases and the associated hazard utilizing the National Atmospheric Release Advisory Center (NARAC) tools and real meteorology at a representative location in the High Plains of the United States. Three cases representing a maximum hazard day (quiet winds <1 m s−1 near the wellhead) and medium and minimal hazard days (average winds 3 m s−1 and 7 m s−1) were assessed. As expected for such large releases, there is a near-well hazard when there is little or no wind. In all three cases the hazardous Temporary Emergency Exposure Levels (TEEL) 2 or 3 only occurred within the first few hundreds of meters. Because the preliminary 3-D model runs may not have been run at high enough resolution to accurately simulate very small distances, we also used a simple Gaussian plume model to provide an upper bound on the distance at which hazardous conditions might exist. This extremely conservative model, which ignores inhomogeneity in the mean wind and turbulence fields, also predicts possible hazardous concentrations up to several hundred meters downwind from a maximal release

Microcapsules for carbon capture from power plants

Microencapsulation has typically been applied to small volume, high value applications like pharmaceuticals and cosmetics. However, the efficient separations and reactions afforded by microcapsules can also be applied to large-scale problems like clean energy. This research focuses on developing microcapsules for energy applications, particularly carbon capture and storage. Please click Additional Files below to see the full abstract

Integrated Geothermal-CO2 Reservoir Systems: Reducing Carbon Intensity through Sustainable Energy Production and Secure CO2 Storage

AbstractLarge-scale geologic CO2 storage (GCS) can be limited by overpressure, while geothermal energy production is often limited by pressure depletion. We investigate how synergistic integration of these complementary systems may enhance the viability of GCS by relieving overpressure, which reduces pore-space competition, the Area of Review, and the risks of CO2 leakage and induced seismicity, and by producing geothermal energy and water, which can defray parasitic energy and water costs of CO2 capture

Learning Companion to Bending the Curve: Climate Change Solutions

The Learning Companion to Bending the Curve: Climate Change Solutions can help all readers gain the most from this book. This resource includes questions for review and discussion which help connect ideas, understand key concepts, and to increase the ability of readers at all levels to effectively discuss and explain climate change solutions.The Learning Companion provides review questions that can be used to assess familiarity with key concepts, ensuring all readers are ready to apply what they’ve learned. These questions can also help instructors identify areas of learning that may require additional explanation. The Learning Companion also provides questions for discussion which can help facilitate both classroom and public discourse, and expanding each reader’s learning about climate change solutionsWe recognize the importance of public communication and education to help promote a broad culture of climate action. Using the questions in the Learning Companion can help you take action, and to collaborate with others as a learning community, focused on climate change solutions