Showing papers on "Brine published in 2013"

Energy recovery from concentrated seawater brine by thin-film nanofiber composite pressure retarded osmosis membranes with high power density

Abstract: A significant amount of energy stored in the form of salinity in seawater reverse osmosis (SWRO) brine can be harvested by a pressure retarded osmosis (PRO) process for power generation. The crucial performance-determining factor of the PRO process is the semi-permeable PRO membrane, which separates the SWRO brine from a lower salinity solution and sustains the salinity difference between the two solutions. However, accumulation of solutes in the support membrane, namely internal concentration polarization (ICP), significantly reduces the effective salinity difference and thus severely limits the efficiency of conventional PRO membranes. In this paper, we report the fabrication and optimization of thin-film nanofiber composite PRO (TNC-PRO) membranes with a unique support membrane structure (inter-connected, low tortuousness and highly porous properties), aiming to facilitate mixing of accumulated solutes with a dilute feed stream and overcome the ICP problem. With such low structure parameter (S) value (150 μm) nanofiber support membranes (NSMs), the optimum water permeability (A) and solute permeability (B) of the TNC-PRO membrane for power generation were determined to be 4.1 L m−2 h−1 bar−1 and 1.74 L m−2 h−1 respectively. This highly efficient TNC-PRO membrane can achieve a power density of 15.2 W m−2 and maximum energy recovery of 0.86 kW h m−3, using synthetic brackish water (80 mM NaCl, π = 3.92 bar) and seawater brine (1.06 M NaCl, π = 51.8 bar) as feed and draw solution, respectively. For a more dilute synthetic river water (0.9 mM NaCl, π = 0.045 bar) feed solution, the same membrane can achieve a higher power density of 21.3 W m−2. The main performance limiting factors in PRO application such as ICP, External Concentration Polarization (ECP) and Reverse Solute Permeation (RSP) are quantified and their values are related to A, B and S values of TNC-PRO membranes.

Dewetting of silica surfaces upon reactions with supercritical CO2 and brine: Pore-scale studies in micromodels - eScholarship

Abstract: Wettability of reservoir minerals and rocks is a critical factor controlling CO(2) mobility, residual trapping, and safe-storage in geologic carbon sequestration, and currently is the factor imparting the greatest uncertainty in predicting capillary behavior in porous media. Very little information on wettability in supercritical CO(2) (scCO(2))-mineral-brine systems is available. We studied pore-scale wettability and wettability alteration in scCO(2)-silica-brine systems using engineered micromodels (transparent pore networks), at 8.5 MPa and 45 °C, over a wide range of NaCl concentrations up to 5.0 M. Dewetting of silica surfaces upon reactions with scCO(2) was observed through water film thinning, water droplet formation, and contact angle increases within single pores. The brine contact angles increased from initial values near 0° up to 80° with larger increases under higher ionic strength conditions. Given the abundance of silica surfaces in reservoirs and caprocks, these results indicate that CO(2) induced dewetting may have important consequences on CO(2) sequestration including reducing capillary entry pressure, and altering quantities of CO(2) residual trapping, relative permeability, and caprock integrity.

Highly selective lithium recovery from brine using a λ-MnO2–Ag battery

Abstract: The demand for lithium has greatly increased with the rapid development of rechargeable batteries. Currently, the main lithium resource is brine lakes, but the conventional lithium recovery process is time consuming, inefficient, and environmentally harmful. Rechargeable batteries have been recently used for lithium recovery, and consist of lithium iron phosphate as a cathode. These batteries feature promising selectivity between lithium and sodium, but they suffer from severe interference from coexisting magnesium ions, an essential component of brine, which has prompted further study. This study reports on a highly selective and energy-efficient lithium recovery system using a rechargeable battery that consists of a λ-MnO2 positive electrode and a chloride-capturing negative electrode. This system can be used to recover lithium from brine even in the presence of magnesium ions as well as other dissolved cations. In addition, lithium recovery from simulated brine is successfully demonstrated, consuming 1.0 W h per 1 mole of lithium recovered, using water similar to that from the artificial brine, which contains various cations (mole ratio: Na/Li ≈ 15.7, K/Li ≈ 2.2, Mg/Li ≈ 1.9).

Experimental Evaluation of Wellbore Integrity Along the Cement-rock Boundary

Abstract: Leakage of CO2 and brine from geologic storage reservoirs along wellbores is a major risk factor to the success of geologic carbon sequestration. We conducted multiphase [supercritical (sc)CO2-brine] coreflood experiments that simulate a leakage pathway along the cement/rock interface. A composite core constructed of oil-well cement and siltstone separated by a simulated damage zone (defect) containing ground cement and siltstone was flooded with brine + scCO2 at 10 MPa and 60 °C parallel to the defect. During coinjection of scCO2, the effective brine permeability decreased from ∼200 to 90 mD due to transition to two-phase flow and then further declined to 35 mD. CO2 injection resulted in a pH drop from 11 to 4 and carbonate-undersaturated conditions in the produced brine. Microscopy revealed leaching and erosion along the defect, a carbonation front extending 5 mm into the cement, parallel to the damage zone, and no change in the dimensions of the defect. Carbonation of cement does not appear to explain ...

Effect of temperature, pressure, salinity, and surfactant concentration on IFT for surfactant flooding optimization

Abstract: In this research, effect of temperature, pressure, salinity, surfactant concentration, and surfactant type on interfacial tension (IFT) and critical micelle concentration of Saudi Arabian crude oil and various aqueous phases were investigated. The temperature ranged from ambient condition to 90°C, and the pressures were varied from atmospheric to 4,000 psi (27.58 MPa). Surfactant solutions were prepared using several aqueous phases, i.e., purified water, 10% brine consisting of 100% NaCl, 10% brine consisting of 95% NaCl and 5% CaCl2, and 10% brine consisting of 83% NaCl and 17% CaCl2. Out of 13 commercial surfactants, only three surfactants showed good solubility in pure water and brine. Those are Zonyl FSE Fluorosurfactant®, Triton X-100®, and Triton X-405®. Therefore, they were investigated thoroughly by measuring their efficiency in reducing the crude oil-aqueous phase IFT. Based on this screening process, laboratory surfactant flooding experiments for crude oil recovery were conducted using Triton X-405 and Triton X-100. The chemical flood was made at both original oil in place and at residual oil in place subsequent to conventional water flooding. Based on the obtained results, both surfactants were efficient, and more oil was recovered than that obtained through water flooding. Comparing both surfactant solutions, it was observed that Triton X-405 was more efficient than Triton X-100 at the same surfactant concentration and reservoir conditions.

Chemical and Mechanical Properties of Wellbore Cement Altered by CO2-Rich Brine Using a Multianalytical Approach

Abstract: Defining chemical and mechanical alteration of wellbore cement by CO2-rich brines is important for predicting the long-term integrity of wellbores in geologic CO2 environments. We reacted CO2-rich brines along a cement-caprock boundary at 60 °C and pCO2 = 3 MPa using flow-through experiments. The results show that distinct reaction zones form in response to reactions with the brine over the 8-day experiment. Detailed characterization of the crystalline and amorphous phases, and the solution chemistry show that the zones can be modeled as preferential portlandite dissolution in the depleted layer, concurrent calcium silicate hydrate (CSH) alteration to an amorphous zeolite and Ca-carbonate precipitation in the carbonate layer, and carbonate dissolution in the amorphous layer. Chemical reaction altered the mechanical properties of the core lowering the average Young’s moduli in the depleted, carbonate, and amorphous layers to approximately 75, 64, and 34% of the unaltered cement, respectively. The decreased...

Solubility of CO2 in Aqueous Solutions of CaCl2 or MgCl2 and in a Synthetic Formation Brine at Temperatures up to 423 K and Pressures up to 40 MPa

Abstract: We report the solubility of carbon dioxide in CaCl2(aq) and MgCl2(aq) at molalities of (1, 3, and 5) mol·kg–1, temperatures of (308 to 424) K and pressures up to 40 MPa. We also report the solubility of CO2 in a synthetic formation brine containing 0.910 mol·kg–1 NaCl and 0.143 mol·kg–1 KCl over the same ranges of temperature and pressure. The expanded uncertainties at 95 % confidence are 0.03 K in temperature, between (0.08 and 0.15) MPa in bubble pressure and 0.00015 in the mole fraction of CO2 in the solution at its bubble point. The results show a strong salting-out effect, whereby the solubility declines with increasing molality of salt, which is some (20 to 30) % greater in CaCl2(aq) or MgCl2(aq) than in the synthetic formation brine at the same molality.

Stabilization of iron oxide nanoparticles in high sodium and calcium brine at high temperatures with adsorbed sulfonated copolymers.

Abstract: A series of sulfonated random and block copolymers were adsorbed on the surface of ∼100 nm iron oxide (IO) nanoparticles (NPs) to provide colloidal stability in extremely concentrated brine composed of 8% wt NaCl + 2% wt CaCl2 (API brine; 1.4 M NaCl + 0.2 M CaCl2) at 90 °C. A combinatorial materials chemistry approach, which employed Ca2+-mediated adsorption of anionic acrylic acid-containing sulfonated polymers to preformed citrate-stabilized IO nanoclusters, enabled the investigation of a large number of polymer coatings. Initially a series of poly(2-methyl-2-acrylamidopropanesulfonate-co-acrylic acid) (poly(AMPS-co-AA)) (1:8 to 1:1 mol:mol), poly(styrenesulfonate-block-acrylic acid) (2.4:1 mol:mol), and poly(styrenesulfonate-alt-maleic acid) (3:1 mol:mol) copolymers were screened for solubility in API brine at 90 °C. The ratio of AMPS to AA groups was varied to balance the requirement of colloid dispersibility at high salinity (provided by AMPS) against the need for anchoring of the polymers to the iro...

Evaluation of the performance of a new freeze desalination technology

Abstract: The use of desalination technologies which produce concentrated brines is acutely limited by inadequate waste brine disposal mechanisms such that the brine does not contaminate fresh water resources. The treatment of highly saline brine using freeze desalination technique trade marked as HybridICE™ technology was investigated at pilot scale. The capacity of the HybridICE™ process to generate fresh water by freeze desalination of brine was investigated in this study. Brine samples to feed into the HybridICE process unit were prepared in tanks with volume capacities between 1.0 and 10.0 m3 by dissolving common salt into tape water. The effects of refrigerant temperature, initial brine concentration, energy consumption were evaluated in relation to product ice quality. Feed brine samples were processed in batches in a closed system where it was continuously re-circulated to generate product ice and more concentrated residual small volume of brine stream. The quality of ice produced could be turned into potable water it terms of its low total dissolved salts and conductivity. The salt removal, based on the average chloride concentration in the ice samples, was 96 %. The energy utilization efficiency amounted to an average of ZAR 10.0/m3 water assuming energy cost of ZAR 0.39/kWh. The HybridICE™ technology was shown to be a better option than other desalination technologies currently in use, in terms of energy utilization and cleaner by-products.

Adsorption of iron oxide nanoclusters stabilized with sulfonated copolymers on silica in concentrated NaCl and CaCl2 brine

Abstract: Transport of metal oxide nanoparticles in porous rock is of interest for imaging and oil recovery in subsurface reservoirs, which often contain concentrated brine. Various copolymers composed of acrylic acid and either 2-acrylamido-2-methylpropanesulfonate or styrenesulfonate were synthesized and adsorbed on iron oxide nanoclusters to provide colloidal stability and to achieve low adsorption on silica in high salinity brine composed of 8%wt. NaCl+2%wt. CaCl2. Furthermore, the degree of adsorption of the nanoparticles on silica was controlled by modifying the acrylic acid groups in the copolymers with a series of diamines and triamines to add hydrophobicity. The adsorption on colloidal silica microparticles ranged from <1 mg/m(2) for highly charged hydrophilic surfaces on the iron oxide nanoparticles to 22 mg/m(2) for the most hydrophobic amine-modified surfaces, corresponding to monolayer coverages that ranged from 0.2% to 11.5%, respectively. The specific adsorption (mg-IO/m(2)-silica), monolayer coverage, and parameters for Langmuir isotherms were evaluated for various IO nanoclusters as a function of the properties of the copolymers on their surfaces.

Experimental Study of Use of Ionic Liquids in Enhanced Oil Recovery

Abstract: Chemical flooding process has shown great potential in Enhanced Oil Recovery (EOR). Unfortunately, chemicals used have some disadvantages such as high cost, high toxicity and high adsorption tendency. In this study, we aim at using Ionic Liquids (ILs) as alternatives for traditional chemicals. Ionic liquids are salts having melting point below 100°C and they found as a liquid at room temperature. Nine Ammonium and Phosphonium based ILs were screened. The screening was based on their solubility in brines of different compositions, thermal stability and ability to reduce the aqueous-oleic phase’s Interfacial Tension (IFT). The screening process flagged Ammoeng 102 as the favored ionic liquid. More investigations of Ammoeng 102 solutions indicated a sharp exponential decrease of IFT values with increasing concentration. On contrary to surfactant solutions, Lower IFT values were obtained with increasing brine salinity indicating the ILs superiority in high salinity reservoirs. Two tertiary flooding experiments were conducted using 500 ppm Ammoeng 102 diluted in 10% and 20% (w/w) brine salinity to investigate its recovery efficiency. Lower salinity secondary brine flooding provided higher recovery. The opposite trend occurred in tertiary ionic solution flooding where recovery is higher for high salinity ionic solution indicating the effectiveness of ILs in recovering oil in high salinity, high temperature environment. In addition, the low cost and low toxicity are more advantages to promote the use of Ionic liquids in future EOR processes.

Effect of Brine Composition on Wettability Alteration of Carbonate Rocks in the Presence of Polar Compounds

Abstract: The impact of brine salinity and ion composition on oil recovery for carbonate reservoirs has been an area of research in recent years. This was motivated by the additional oil recovery that was recovered by low salinity and ionic modifications in sandstone and chalk reservoirs and to some extent in carbonate reservoirs. Wettability alteration to more water-wet conditions has been proposed as the mechanism leading to the additional oil recovery.

Na+, Ca2+, and Mg2+ in brines affect supercritical CO2-brine-biotite interactions: ion exchange, biotite dissolution, and illite precipitation.

Abstract: For sustainable geologic CO2 sequestration (GCS), a better understanding of the effects of brine cation compositions on mica dissolution, surface morphological change, and secondary mineral precipitation under saline hydrothermal conditions is needed. Batch dissolution experiments were conducted with biotite under conditions relevant to GCS sites (55–95 °C and 102 atm CO2). One molar NaCl, 0.4 M MgCl2, or 0.4 M CaCl2 solutions were used to mimic different brine compositions, and deionized water was used for comparison. Faster ion exchange reactions (Na+–K+, Mg2+–K+, and Ca2+–K+) occurred in these salt solutions than in water (H+–K+). The ion exchange reactions affected bump, bulge, and crack formation on the biotite basal plane, as well as the release of biotite framework ions. In these salt solutions, numerous illite fibers precipitated after reaction for only 3 h at 95 °C. Interestingly, in slow illite precipitation processes, oriented aggregation of hexagonal nanoparticles forming the fibrous illite wa...

Brinicles as a case of inverse chemical gardens

Abstract: Brinicles are hollow tubes of ice from centimetres to metres in length that form under floating sea ice in the polar oceans when dense, cold brine drains downwards from sea ice into sea water close to its freezing point. When this extremely cold brine leaves the ice it freezes the water it comes into contact with; a hollow tube of ice --- a brinicle --- growing downwards around the plume of descending brine. We show that brinicles can be understood as a form of the self-assembled tubular precipitation structures termed chemical gardens, plant-like structures formed on placing together a soluble metal salt, often in the form of a seed crystal, and an aqueous solution of one of many anions, often silicate. On one hand, in the case of classical chemical gardens, an osmotic pressure difference across a semipermeable precipitation membrane that filters solutions by rejecting the solute leads to an inflow of water and to its rupture. The internal solution, generally being lighter than the external solution, flows up through the break, and as it does so a tube grows upwards by precipitation around the jet of internal solution. Such chemical-garden tubes can grow to many centimetres in length. In the case of brinicles, on the other hand, in floating sea ice we have porous ice in a mushy layer that filters out water, by freezing it, and allows concentrated brine through. Again there is an osmotic pressure difference leading to a continuing ingress of sea water in a siphon pump mechanism that is sustained as long as the ice continues to freeze. Since the brine that is pumped out is denser than the sea water, and descends rather rises, a brinicle is a downwards growing tube of ice; an inverse chemical garden.

Geochemical Impacts of Sequestering Carbon Dioxide in Brine Formations

Abstract: The purpose of this chapter is to lay out potential geochemical impacts of geologic sequestration. Injection of supercritical carbon dioxide into a brine formation shifts rock-dominated reaction systems to fluid-dominated systems controlled by acid-generating reactions and mixed-fluid equilibria. Increased carbonic acid content in the brine reduces the pH of in situ brine by approximately 1.5―4 pH units, depending on brine chemistry, formation lithology, and temperature, to a pH value between 3.5 and 4. Alkalinity is also produced by reaction of carbonic acid with reservoir minerals, but alkalinity of in situ brine cannot overcome the acidity produced by dissolution of supercritical carbon dioxide fluid. Analysis suggests that displacement of brine as injection proceeds will lead to separation from supercritical carbon dioxide fluid and loss of saturated carbon dioxide, wherein alkalinity can neutralize the acidity, yielding near-neutral to alkaline pH. Silica concentrations and dissolution rates will become enhanced, whereas silica precipitation is inhibited by acidic brine. Acidified brine will also react with both reservoir rock and caprock, enriching the brine in metal cations and creating alkalinity. As silica-supersaturated, metal-laden brine migrates into areas without carbon dioxide, in situ monitoring can be used to indicate repository performance. Return of silica-supersaturated brine to a rock-dominated reaction system buffered to neutral pH conditions may enhance precipitation of quartz, chalcedony, or amorphous silica. Reaction kinetics among supercritical carbon dioxide, brine, and rock are comparable to rates in systems containing gaseous carbon dioxide.