Showing papers on "Brine published in 2010"

Laboratory flow experiments for visualizing carbon dioxide-induced, density-driven brine convection

Abstract: Injection of carbon dioxide (CO2) into saline aquifers confined by low- permeability cap rock will result in a layer of CO2 overlying the brine. Dissolution of CO2 into the brine increases the brine density, resulting in an unstable situation in which more-dense brine overlies less-dense brine. This gravitational instability could give rise to density-driven convection of the fluid, which is a favorable process of practical interest for CO2 storage security because it accelerates the transfer of buoyant CO2 into the aqueous phase, where it is no longer subject to an upward buoyant drive. Laboratory flow visualization tests in transparent Hele-Shaw cells have been performed to elucidate the processes and rates of this CO2 solute-driven convection (CSC). Upon introduction of CO2 into the system, a layer of CO2-laden brine forms at the CO2-water interface. Subsequently, small convective fingers form, which coalesce, broaden, and penetrate into the test cell. Images and time-series data of finger lengths and wavelengths are presented. Observed CO2 uptake of the convection system indicates that the CO2 dissolution rate is approximately constant for each test and is far greater than expected for a diffusion-only scenario. Numerical simulations of our system show good agreement with the experiments for onset time of convection and advancement of convective fingers. There are differences as well, the most prominent being the absence of cell-scale convection in the numerical simulations. This cell-scale convection observed in the experiments may be an artifact of a small temperature gradient induced by the cell illumination.

Stability of Partially Hydrolyzed Polyacrylamides at Elevated Temperatures in the Absence of Divalent Cations

Abstract: Summary At elevated temperatures in aqueous solution, partially hydrolyzed polyacrylamides (HPAMs) experience hydrolysis of amide side groups. However, in the absence of dissolved oxygen and divalent cations, the polymer backbone can remain stable so that HPAM solutions were projected to maintain at least half their original viscosity for more than 8 years at 100°C and for approximately 2 years at 120°C. Within our experimental error, HPAM stability was the same with and without oil (decane). An acrylamide-AMPS copolymer [with 25% 2-acrylamido-2-methylpropane sulphonic acid (AMPS)] showed similar stability to that for HPAM. Stability results were similar in brines with 0.3% NaCl, 3% NaCl, or 0.2% NaCl plus 0.1% NaHCO3. At temperatures of 160°C and greater, the polymers were more stable in brine with 2% NaCl plus 1% NaHCO3 than in the other brines. Even though no chemical oxygen scavengers or antioxidants were used in our study, we observed the highest level of thermal stability reported to date for these polymers. Our results provide considerable hope for the use of HPAM polymers in enhanced oil recovery (EOR) at temperatures up to 120°C if contact with dissolved oxygen and divalent cations can be minimized. Calculations performed considering oxygen reaction with oil and pyrite revealed that dissolved oxygen will be removed quickly from injected waters and will not propagate very far into porous reservoir rock. These findings have two positive implications with respect to polymer floods in high-temperature reservoirs. First, dissolved oxygen that entered the reservoir before polymer injection will have been consumed and will not aggravate polymer degradation. Second, if an oxygen leak (in the surface facilities or piping) develops during the course of polymer injection, that oxygen will not compromise the stability of the polymer that was injected before the leak developed or the polymer that is injected after the leak is fixed. Of course, the polymer that is injected while the leak is active will be susceptible to oxidative degradation. Maintaining dissolved oxygen at undetectable levels is necessary to maximize polymer stability. This can be accomplished readily without the use of chemical oxygen scavengers or antioxidants.

Laboratory flow experiments for visualizing carbon dioxide-induced, density-driven brine convection

Abstract: Laboratory Flow Experiments for Visualizing Carbon Dioxide-Induced, Density- Driven Brine Convection Timothy J. Kneafsey and Karsten Pruess Lawrence Berkeley National Laboratory Berkeley, California TJKneafsey@lbl.gov Abstract Injection of carbon dioxide (CO 2 ) into saline aquifers confined by low-permeability cap rock will result in a layer of CO 2 overlying the brine. Dissolution of CO 2 into the brine increases the brine density, resulting in an unstable situation in which more-dense brine overlies less-dense brine. This gravitational instability could give rise to density-driven convection of the fluid, which is a favorable process of practical interest for CO 2 storage security because it accelerates the transfer of buoyant CO 2 into the aqueous phase, where it is no longer subject to an upward buoyant drive. Laboratory flow visualization tests in transparent Hele-Shaw cells have been performed to elucidate the processes and rates of this CO2 solute-driven convection (CSC). Upon introduction of CO 2 into the system, a layer of CO 2 -laden brine forms at the CO 2 -water interface. Subsequently, small convective fingers form, which coalesce, broaden, and penetrate into the test cell. Images and time-series data of finger lengths and wavelengths are presented. Observed CO 2 uptake of the convection system indicates that the CO 2 dissolution rate is approximately constant for each test and is far greater than expected for a diffusion-only scenario. Numerical simulations of our system show good agreement with the experiments for onset time of convection and advancement of convective fingers. There are differences as well, the most prominent being the absence of cell-scale convection in the numerical simulations. This cell-scale convection observed in the experiments is probably initiated by a small temperature gradient induced by the cell illumination. Introduction Carbon dioxide (CO 2 ) injection into deep saline aquifers is a method being considered for sequestration of CO 2 . In such a scenario, the CO 2 would be injected into a permeable,

Reactive transport modeling to study changes in water chemistry induced by CO2 injection at the Frio-I brine pilot

Abstract: Reactive Transport Modeling to Study Changes in Water Chemistry Induced by CO 2 Injection at the Frio-I Brine Pilot Tianfu Xu 1 , Yousif K. Kharaka 2 , Christine Doughty 1 , Barry M. Freifeld 1 , and Thomas M. Daley 1 Earth Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 U.S. Geological Survey, MS/427, 345 Middlefield Rd., Menlo Park, CA 94025 Abstract. To demonstrate the potential for geologic storage of CO 2 in saline aquifers, the Frio-I Brine Pilot was conducted, during which 1600 tons of CO 2 were injected into a high-permeability sandstone and the resulting subsurface plume of CO 2 was monitored using a variety of hydrogeological, geophysical, and geochemical techniques . Fluid samples were obtained before CO 2 injection for baseline geochemical characterization, during the CO 2 injection to track its breakthrough at a nearby observation well, and after injection to investigate changes in fluid composition and potential leakage into an overlying zone. Following CO 2 breakthrough at the observation well, brine samples showed sharp drops in pH, pronounced increases in HCO 3- and aqueous Fe, and significant shifts in the isotopic compositions of H 2 O and dissolved inorganic carbon. Based on a calibrated 1-D radial flow model, reactive transport modeling was performed for the Frio-I Brine Pilot. A simple kinetic model of Fe release from the solid to aqueous phase was developed, which can reproduce the observed increases in aqueous Fe concentration. Brine samples collected after half a year had lower Fe concentrations due to carbonate precipitation, and this trend can be also captured by our modeling. The paper provides a method for estimating potential mobile Fe inventory, and its bounding concentration in the storage formation from limited observation data. Long-term simulations show that the CO 2 plume gradually spreads outward due to capillary forces, and the gas saturation gradually decreases due to its dissolution and precipitation of carbonates. The gas phase is predicted to disappear after 500 years. Elevated aqueous CO 2 concentrations remain for a longer time, but eventually decrease due to carbonate precipitation. For the Frio-I Brine Pilot, all injected CO 2 could ultimately be sequestered as carbonate minerals. Keywords: CO 2 sequestration, Frio Formation, Water chemistry, Iron release, Reactive transport modeling

Brine–rock interaction in the Athabasca basement (McArthur River U deposit, Canada): consequences for fluid chemistry and uranium uptake

Abstract: Terra Nova, 22, 303–308, 2010 Abstract The nature of uranium source rocks, transport conditions and deposition processes are still highly controversial for world-class unconformity-related U deposits. This article presents the first detailed chemistry of brines associated with the giant McArthur River U deposit, Canada. LA-ICP-MS analysis of individual fluid inclusions suggests mixing between a Na–Ca–Mg–K–Sr–Ba brine and a Ca–Mg–Na–K–Sr–Ba brine. The brines share a common origin (evaporated seawater) and show evidence for contrasting interaction with basement rocks. The Na-rich brine lost Mg and K in alteration haloes around U ores, while the Ca-rich brine results from Na–Ca exchange and Sr–Ba gain. U concentrations (0.3–530 μg g−1) are anomalously high compared with usual basinal fluids, this indicating that U uptake occurred within basement rocks. The two brine end-members have mixed within the main U deposit area, which could be one of the major driving forces for U deposition.

Continuous salt precipitation and separation from supercritical water. Part 2. Type 2 salts and mixtures of two salts

Abstract: Using a continuously operated laboratory plant for the catalytic hydrothermal gasification of biomass featuring a supercritical water salt separator we investigated the separation performance of three different binary type 2 salt–water mixtures and three ternary salt–water mixtures that consisted either of two type 1 salts or two type 2 salts dissolved in water. It turned out that a concentrated salt brine could not be recovered at the salt separator for the binary type 2 salt–water mixtures of Na 2 CO 3 , Na 2 SO 4 , and K 2 SO 4 . These salts precipitate as solids from supercritical water and thus lead to salt deposits inside the salt separator vessel. The ternary mixtures of two type 1 salts dissolved in water (KH 2 PO 4 –K 2 HPO 4 –H 2 O and three different mixtures of NaNO 3 –K 2 CO 3 –water) exhibited a separation performance similar to the binary solutions of type 1 salts that were discussed in Part 1 of this article. However, the mixtures showed separation performances that were different from the corresponding single salt solutions. It was also possible to recover a concentrated brine when feeding solutions containing the two type 2 salts Na 2 CO 3 and K 2 SO 4 . For these mixtures a certain amount of the type 1 salt K 2 CO 3 might form in supercritical water leading to salt separation efficiencies up to 95% for these mixtures.

Experimental Study on the Dissociation Behavior and Productivity of Gas Hydrate by Brine Injection Scheme in Porous Rock

Abstract: This study presents the experimental apparatus to analyze the dissociating phenomena of gas hydrate in porous rock. The experiments by brine injection scheme have been carried out in a way that can...

New Constraints on Methane Fluxes and Rates of Anaerobic Methane Oxidation in a Gulf of Mexico Brine Pool via In Situ Mass Spectrometry

Abstract: Deep-sea biogeochemical cycles are, in general, poorly understood owing to the difficulties of making measurements in situ, recovering samples with minimal perturbation, and, in many cases, coping with high spatial and temporal heterogeneity. In particular, biogeochemical fluxes of volatiles such as methane remain largely unconstrained because of the difficulties with accurate quantification in situ and the patchiness of point sources such as seeps and brine pools. To better constrain biogeochemical fluxes and cycling, we have developed a deep-sea in situ mass spectrometer (ISMS) to enable high-resolution quantification of volatiles in situ. Here we report direct measurements of methane concentrations made in a Gulf of Mexico brine pool located at a depth of over 2300 m. Concentrations of up to 33 mM methane were observed within the brine pool, whereas concentrations in the water directly above were three orders of magnitude lower. These direct measurements enabled us to make the first accurate estimates of the diffusive flux from a brine pool, calculated to be 1.1±0.2 mol m−2 yr−1. Integrated rate measurements of aerobic methane oxidation in the water column overlying the brine pool were ∼320 μmol m−2 yr−1, accounting at most for just 0.03% of the diffusive methane flux from the brine pool. Calculated rates of anaerobic methane oxidation were 600–1200 μM yr−1, one to two orders of magnitude higher than previously published values of AOM in anoxic fluids. These findings suggest that brine pools are enormous point sources of methane in the deep sea, and may, in aggregate, have a pronounced impact on the global marine methane cycle.

Design of a Eutectic Freeze Crystallization process for multicomponent waste water stream

Abstract: Complex, hypersaline brines originating from the mining and extractive metallurgical industries have the potential to be treated using Eutectic Freeze Crystallization (EFC). Although EFC has been shown to be effective in separating a single salt and water, it has yet to be applied to the complex hypersaline brines that are typical of reverse osmosis retentates in South Africa. This paper focuses on the application of EFC for the purification of a typical brine containing high levels of sodium, chlorine, sulphate and ammonia that cannot be achieved with other separation techniques. The presence of ammonia prevents the application of membrane technology to treat the brine, leaving only cooling or evaporation as other possible options. Evaporation produces a mixed salt that requires further treatment. Modelling tools were applied to describe the phase behaviour of the complex saline systems under different process conditions and were experimentally validated. The results showed that Eutectic Freeze Crystallization could be used to selectively recover the sodium as a sodium sulphate salt. The simulation tools were especially useful in the design and optimisation of the process.

Imidazole-fe interaction in an aqueous chloride medium: effect of cathodic reduction of the native oxide.

Abstract: The effect of the reduction of the native surface oxide of Fe on the binding of imidazole (as a corrosion inhibitor) with Fe in an aqueous brine solution has been addressed here The surface interactions and corrosion inhibition efficiency were studied using X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS) It was shown that imidazole dissolved in brine bonds with the unreduced iron oxide surface via pyrrole-type nitrogen However, surface interactions with Fe occur via both pyridine-type and pyrrole-type nitrogen atoms when imidazole is added to brine containing a cathodically reduced iron surface The packing density of imidazole is found to be higher in the latter case with a corresponding increase in the corrosion inhibition efficiency

Brines in supercritical biomass gasification: 1.Salt extraction by salts and the influence on glucose conversion

Abstract: The hydrothermal gasification of wet biomass is a promising process to use biomass residues of high water content to produce burnable gases. Here “green” biomass can be converted without prior drying. Recently important improvements are accomplished, but still challenges in view of the technical application exists. One of the most important challenges is the handling of salts as natural ingredients of biomass. In this study, salts forming a second salt-rich aqueous phase (hydrothermal brine) are used to catch other salts, to avoid plugging of the reactor by formation of solids. The sodium salts studied, were successfully captured by the hydrothermal brine, which also influences the conversion of glucose as model compound for biomass.

WAIV - Wind aided intensified evaporation for brine volume reduction and generating mineral byproducts

Abstract: In this study bench pilot WAIV units (∼ 1 m2 evaporation area loaded on 0.17 m2 footprint) were operated on two different desalination brines (RO and ED) as well as on a mineral brine concentrate under arid conditions of the Negev Highlands. The evaporation rate with the WAIV unit on these feeds often gave evaporation rates per footprint that were 10-fold or greater than the pan evaporation rate obtained from the local meteorological station at Sde Boker. Desalination brines were concentrated up to 23% TDS when operating on ED concentrate. The evaporation from the WAIV unit demonstrated enrichment in the magnesium ion compared to the calcium and the sodium ion, including over a two-fold enrichment of magnesium relative to calcium as would be expected by the equilibrium solubilities of the different minerals. Despite precipitation of minerals, there is not a large buildup of deposit on the flexible evaporation surface, and this helps establish the feasibility for recovering minerals from the desalination b...

Freezing desalination of sea water in a static layer crystallizer

Abstract: This work aims in developing a static layer crystallizer for freezing desalination of sea water. The experiments were performed with a simple system of H2O-NaCl and with samples of sea water from Rabat. The pilot crystallizer consists in a tube cooled bymeans of a thermostatic bath. The tube is immerged in a cylindrical double jacketed tank cooled by means of a second thermostatic bath. The brine is poured into the tank and the crystallization takes place on the external surface of the tube. The global process is divided into 4 steps: (i) crystallization of the ice layer by controlling the cooling rate in the tube (ii) draining off the concentrated brine (iii) purification of the layer by sweating and (iv) melting of the ice to recover the fresh water. A parametric study of the effect of the operating parameters has allowed us to quantify the role of the different key parameters of the crystallization step. Within the studied domain, the purity of the crystalline layer was mainly affected by the initial s...

Recovery of Na2SO4·10H2O from a reverse osmosis retentate by eutectic freeze crystallisation technology

Abstract: The increasing amount of waste water and effluent from South Africa's mining industry forms a growing problem, which processing requires sustainable solutions in which both the water and the dissolved component can be re-used. Eutectic freeze crystallisation (EFC) has been identified as a key technology that is not only energy efficient, but also produces ice and salt products of high quality. Unlike reverse osmosis membrane systems, EFC can treat both dilute and concentrated systems minimising waste water volumes. In this paper it is shown that freeze and eutectic freeze crystallisation can be used for the processing of a reverse osmosis retentate stream containing 4% NaSO4 and a number of impurities (F, Cl, K, Li, Mg, Ca, NO3 and NH4), producing both pure water and NaSO4·10H2O crystals. The influence of the impurities on the eutectic point and on the crystal structure of mirabilite was investigated using EFC technology investigated for a pure binary system, for a synthetic reverse osmosis retentate as well as for a concentrated NaCl system. In addition, investigations into the recovery and purity of mirabilite for these streams were conducted.

Method of making pure salt from FRAC-water/wastewater

Abstract: The present invention relates to a method for making pure salt comprises recapturing post-drilling flowback water from hydro-fracturing; removing oil from the flowback water; filtering the flowback water using an ultra filter with a pore size of about 0.1 microns or less to remove solid particulates and large organic molecules, such as benzene, ethylbenzene, toluene, and xylene, from the water; concentrating the flowback water to produce a brine that contains from about 15 wt % to about 40 wt % of salt relative to the total weight of the flowback brine; performing one or more chemical precipitation process using an effective amount of reagents to precipitate out the desired high quality commercial products, such as, barium sulfate, strontium carbonate, calcium carbonate; and crystallizing the chemically treated and concentrated flowback brine to produce greater than 99.5% pure salt products, such as sodium and calcium chloride.

Effect of Salinity on Wettability Alteration to Intermediate Gas-Wetting

Abstract: Summary The effect of salinity on the alteration of wettability from waterwetting to intermediate gas-wetting is studied in this work. We find that NaCl salinity increases water-wetting when a core is saturated with brine. NaCl also reduces gas absolute permeability, as reported in the literature. CaCl2 salinity effect is dramatically different from that of NaCl brine and has a minor effect on permeability. The NaCl, KCl, and CaCl2 brines have an adverse effect on wettability alteration. To alleviate the effect of salt on chemical treatment, we suggest pretreatment by displacement of brine with water and subsequent drainage by nitrogen.

Reuse of RO Desalination Plant Reject Brine

Abstract: In this work we try to study the feasibility of salt production from a reject brine coming from a desalination plant in Skhira in the south of Tunisia, This plant treats 22,008 m3/day of raw water to produce 9984 m3 of fresh water and 12,024 m3 of rejected water and has the advantages of being environmentally friendly and producing commercial products in crystalline, slurry, and liquid forms. The process involves an application of the solubility diagrams in order to valorize the reject brines. These solutions are considered as strongly concentrated brines and containing several elements such as: Na+, K+, Mg2+, Ca2+, Cl−, and SO42−. This observation leads us to consider the complete hexary system Na+, Mg2+, K+, Ca2+/Cl−, SO42−//H2O which includes four quinary systems. A number of physico-chemical analyses were employed (Potentiometry, complexometry, gravimetry, XRD, and SEM). At the end of an isothermal and isobaric evaporation of the reject brine, we could recover various salts (NaCl, KCl, CaSO4·2H2O, MgSO4·7H2O…) very useful for industry and agriculture.

Different photolysis kinetics at the surface of frozen freshwater vs. frozen salt solutions

Abstract: . Reactions at air-ice interfaces can proceed at very different rates than those in aqueous solution, due to the unique disordered region at the ice surface known as the quasi-liquid layer (QLL) . The physical and chemical nature of the surfacial region of ice is greatly affected by solutes such as sodium halide salts. In this work, we studied the effects of sodium chloride and sodium bromide on the photolysis kinetics of harmine, an aromatic organic compound, in aqueous solution and at the surface of frozen salt solutions above the eutectic temperature. In common with other aromatic organic compounds we have studied, harmine photolysis is much faster on ice surfaces than in aqueous solution, but the presence of NaCl or NaBr – which does not affect photolysis kinetics in solution – reduces the photolysis rate on ice. The rate decreases monotonically with increasing salt concentration; at the concentrations found in seawater, harmine photolysis at the surface of frozen salt solutions proceeds at the same rate as in aqueous solution. These results suggest that the brine excluded to the surfaces of frozen salt solutions is a true aqueous solution, and so it may be possible to use aqueous-phase kinetics to predict photolysis rates at sea ice surfaces. This is in marked contrast to the result at the surface of frozen freshwater samples, where reaction kinetics are often not well-described by aqueous-phase processes.

Process of using hard brine at high alkalinity for enhanced oil recovery (eor) applications

Abstract: The present invention describes the use of EDTA and/or alkali treated hard brine at high pH for making ASP formulations for EOR applications.