Simulated Brine Research Articles

Impact of sub-core scale heterogeneity on CO2/brine multiphase flow for geological carbon storage in the upper Minnelusa sandstones

This study aims at understanding effects of sub-core scale petrophysical heterogeneity on CO2-brine multiphase flow properties during CO2 injection in samples of the Minnelusa Formation in Wyoming, representing differing lithofacies. Unsteady-state CO2-brine drainage tests were performed on a core sample from a dune deposit with laminated bedding and poorly sorted grain distribution. To highlight the role of low-porosity and low-permeability bedding layers (LLBL) on CO2 migration during CO2 injection, a contrasting coreflooding experiment was conducted on a sample of well-sorted sandstone collected from an interdune deposit. Assisted history matching was used to estimate the corresponding core-scale relative permeability curves, a procedure that reveals heterogeneity-dependent behavior. The simulated brine production from the optimal history matching case suggests that the main variation in multiphase flow properties could be attributed to internal permeability structures, i.e. sub-core scale LLBL, leading, in turn, to capillary pressure heterogeneity. CO2 sweep efficiency and distribution in heterogeneous Eolian sandstone are hard to estimate based solely on the limited number of coreflooding experiments, due to LLBL properties variability. Consequently, sensitivity analyses for the properties of sub-core scale LLBL on core-scale brine production were conducted using the developed model. Analyses indicate that the residual brine saturation and thickness of LLBL have a more significant effect on bulk brine production, whereas the impact of CO2 end-point relative permeability of LLBL on bulk brine production is negligible. In addition, comparison results show that ignoring the sub-core scale heterogeneity (e.g. sub-core scale relative permeability) during CO2 injection can create significant uncertainties in storage and fluid flow displacement in simulated results, due to important flow effects and thereby physically insightful responses. Overall, this study provides us with a deeper understanding of core-scale CO2-brine multiphase flow properties for CO2 geological storage in heterogeneous sandstones and gained us insights into CO2-brine multiphase flow upscaling in heterogeneous geological models. Our approach needs to be incorporated in upscaling procedures to avoid smearing key small-scale features, relevant to multiphase flow behaviour.

Preparation and displacement performance of HAPC copolymer suitable for ultra-high saline reservoirs

The modified polyacrylamide (HAPC) based on a benzene ring and an ethoxy chain that can bind metal ions was successfully prepared by micellar polymerization. The structure of HAPC was characterized by Fourier infrared spectroscopy and hydrogen nuclear magnetic spectroscopy. Some properties of the polymer were evaluated, and the temperature resistance, salt resistance, rheological properties, aging resistance and oil displacement physical simulation experiments of HAPC were studied. The experimental results show that the introduction of benzene ring and ethoxy chain greatly improved the salt resistance of the polymer. Among them, the maximum viscosity can be increased by about 5 times in the calcium chloride and magnesium chloride divalent ion solution. When the concentration was 12000 mg/L and the concentration of magnesium chloride was 16000 mg/L, the viscosity retention rate was 63.5% and 90% respectively; The physical simulation experiment of oil displacement shows that HAPC can increase the oil recovery rate by 19.85% at 80 °C and high salt concentration (1.0 × 105 mg/L simulated brine).

Impact of Ca(II) on the aqueous speciation, redox behavior, and environmental mobility of Pu(IV) in the presence of EDTA

The impact of calcium on the solubility and redox behavior of the Pu(IV)-EDTA system was investigated using a combination of undersaturation solubility studies and advanced spectroscopic techniques. Batch solubility experiments were conducted in 0.1 M NaCl-NaOH-HCl-EDTA-CaCl2 solutions at constant [EDTA] = 1∙10−3 M, 1 ≤ pHm ≤ 11, and 1∙10−3 M ≤ [CaCl2] ≤ 2∙10−2 M. Additional samples targeted brine systems represented by 3.5 M CaCl2 and WIPP simulated brine. Redox conditions were buffered with hydroquinone (pe + pH ≈ 9.5) with selected samples prepared in the absence of any redox buffer. All experiments were performed at T = 22 °C under Ar atmosphere. In-situ X-ray absorption spectroscopy indicated that PuO2(ncr,hyd) was the solubility-controlling phase during the lifetime of all experiments and that aqueous plutonium was present in the +IV oxidation state across all experimental conditions except at pHm ≈ 1, where a small fraction of Pu(III) was also identified. Current thermodynamic models overestimate Pu(IV)-EDTA solubility in the absence of calcium by approximately 1–1.5 log10-units and do not describe the nearly pH-independent, increased solubility observed with increased calcium concentrations. The ternary Pu(IV)-OH-EDTA system without calcium was reevaluated using solubility data obtained in this work and reported in the literature. An updated thermodynamic model including the complexes Pu(OH)(EDTA)−, Pu(OH)2(EDTA)2−, and Pu(OH)3(EDTA)3− was derived. Solubility data collected in the presence of calcium follows a pH-independent trend (log m(Pu)tot vs. pHm), which can only be explained by assuming the formation of a quaternary complex, tentatively defined as CaPu(OH)4(EDTA)2−, in solution. The significant enhancement of plutonium solubility observed in the investigated brine systems supports the formation of a quaternary complex that is not outcompeted by Ca(EDTA)2−, even in concentrated CaCl2 solutions. Although the exact stoichiometry of the complex may need to be revisited, this new quaternary complex has a pronounced impact on plutonium predominance diagrams over a broad range of pH, pe, and calcium concentrations that are relevant to nuclear waste disposal.

A scalable three-dimensional porous λ-MnO2/rGO/Ca-alginate composite electroactive film with potential-responsive ion-pumping effect for selective recovery of lithium ions

A scalable three-dimensional (3D) porous composite electroactive film consisting of λ-MnO2, reduced graphene oxide (rGO) and calcium alginate (Ca-alg) was successfully fabricated and employed for the selective extraction of Li+ ions with low concentration via an electrochemically switched ion exchange (ESIX) technology. The Li+ ion adsorption capacity of the obtained λ-MnO2/rGO/Ca-alg composite electroactive film reached as high as 32.7 mg g−1 and more than 90% of its equilibrium adsorption capacity was achieved in 1 h. The λ-MnO2/rGO/Ca-alg composite electroactive film displayed evident selectivity towards Li+ ions. The separation factors for Li+/Na+ and Li+/Mg2+ reached 1040.57 and 358.96, respectively, while tested in simulated brine. The composite film also showed superior electrochemical stability, and the normalized ion exchange capacity retained at 98.3% of its initial value even after 100 successive cycles. The excellent Li+ ion recovery performance of the obtained composite film should be attributed to its low ion transfer resistance owing to the porous network structure and the potential-responsive ion-pumping effect in the ESIX process. In addition, a large-scale of such a composite electroactive film could be effectively fabricated by controlling the spreading area of the mixed solution consisting of λ-MnO2, rGO and alginate binder. It is expected that such a scalable 3D porous composite film could be a promising alternative for the recovery of lithium ions from salt lake brine.

Dual-skin layer nanofiltration membranes for highly selective Li+/Mg2+ separation

The wide application of lithium batteries in consumer electronics and electric vehicles bring about ever-rising demand of lithium resources globally. Nanofiltration (NF) membranes with high Mg2+/Li+ selectivity could achieve highly efficient separation of lithium from natural brines, which provides a good alternative for steady lithium supply. In this work, we developed a dual-skin layer nanofiltration membrane comprised of a polyethylene-imine (PEI) layer grafted on a polyamide layer. The polyamide layer was prepared via interfacial polymerization to endow the NF membrane with sub-nm pores, while the PEI layer was grafted on the polyamide surface via amidation reaction to further equip the membrane with enhanced positive charge. With the synergistic effect of size sieving from the polyamide layer and electrostatic exclusion from the PEI layer, the dual-skin layer NF membrane exhibits a high rejection of 98.5% to MgCl2 and a low rejection of 46.2% to LiCl, suggesting a high Mg2+/Li+ selectivity. As using this dual-skin layer NF membrane for separating Li+ from a simulated brine, a high Mg2+/Li+ separation factor (SMg,Li) up to 33.4 was achieved, which is the highest value among the pressure-driven polymeric nanofiltration membranes reported so far.

Synthesis and Solution Properties of a Novel Hyperbranched Polymer Based on Chitosan for Enhanced Oil Recovery

A new type of chitosan-modified hyperbranched polymer (named HPDACS) was synthesized through the free-radical polymerization of surface-modified chitosan with acrylic acid (AA) and acrylamide (AM) to achieve an enhanced oil recovery. The optimal polymerization conditions of HPDACS were explored and its structure was characterized by Fourier-transform infrared spectroscopy, hydrogen nuclear magnetic resonance, and environmental scanning electron microscopy. The solution properties of HPDACS in ultrapure water and simulated brine were deeply studied and then compared with those of partially hydrolyzed polyacrylamide (HPAM) and a dendritic polymer named HPDA. The experimental results showed that HPDACS has a good thickening ability, temperature resistance, and salt resistance. Its viscosity retention rate exceeded 79.49% after 90 days of aging, thus meeting the performance requirements of polymer flooding. After mechanical shearing, the viscosity retention rates of HPDACS in ultrapure water and simulated brine were higher than those of HPAM and HPDA, indicating its excellent shear resistance and good viscoelasticity. Following a 95% water cut after preliminary water flooding, 0.3 pore volume (PV) and 1500 mg/L HPDACS solution flooding and extended water flooding could further increase the oil recovery by 19.20%, which was higher than that by HPAM at 10.65% and HPDA at 13.72%. This finding indicates that HPDACS has great potential for oil displacement.

Preparation and adsorption performance of multi-morphology H1.6Mn1.6O4 for lithium extraction

In this paper, a lithium-ion sieve (LIS) with different morphologies, such as rod-like (LIS-R), spherical (LIS-S), flower-like (LIS-F), and three-dimensional macroporous-mesoporous (LIS-3D), was prepared by hydrothermal synthesis, solid reaction, and hard-template synthesis. The results showed that the LIS with different morphologies presented great differences in specific surface area, pore volume, adsorption selectivity, and structure stability. LIS-3D with highest specific surface area and pore volume displayed the maximum adsorption capacity and adsorption rate, but the stability of LIS-3D was poor because of the manganese dissolution. By comparison, LIS-S has the best structural stability while maintaining a satisfactory adsorption capacity (35.02 mg·g−1) and adsorption rate. The LIS-S remained about 90% of the original adsorption capacity after five cycles of adsorption–desorption process. In addition, in the simulated brine system (the magnesium to lithium ratio of 400), the LIS-S exhibited the highest selectivity (αLiMg) of 425.14. In sum, the LIS-S with good morphology is a potential adsorbent for lithium extraction from brine.

Laboratory Method to Assess Efficacy of Dust Suppressants for Dirt and Gravel Roads

Particulate matter (PM) generated from dirt and gravel roads is a concern for both human and environmental health. To help reduce the amount of PM generated, many states allow the use of water coproduced from oil and gas wells (i.e., brines) as road dust suppressants. However, few methods exist to quantify the effectiveness of these brines and other dust suppressants. Here we designed and tested a bench-scale method to test the efficacy of dust suppressants on dirt and gravel road materials. The Standard Proctor test was modified to create discs of road aggregate that could be treated with dust suppressant, dried, and then tumbled in a mechanical drum attached to an aerosol monitor that measured PM generated within the drum. Using two types of road aggregate (DSA and 2RC) and a combination of nine simulated brines, the effects of brine total dissolved solids (TDS), and sodium adsorption ratio (SAR) on dust suppression were calculated. The effects of moisture content and aggregate type were also observed. Higher TDS and lower SAR were found to be good predictors of dust-suppression effectiveness, with the degree of effectiveness partially dependent on the type of road aggregate. The test method provides a means to quickly and reproducibly compare effectiveness of dust suppressants, with other variables such as aggregate type and moisture content, to accurately estimate dust suppression. Comparisons of dust measurements collected within the laboratory and vehicle-based measurements offer the ability to relate laboratory results to conditions encountered on dirt and gravel roads.

Recovery of Rubidium and Cesium Resources from Brine of Desalination through t-BAMBP Extraction

50 billion cubic meters of brine every year creates ecological hazards to the environment. In order to reuse brine efficiently, rubidium and cesium were recovered in this experiment. On the other hand, the main impurities which were needed to be eliminated in brine were lithium, sodium, potassium, calcium, and magnesium. In the procedure, seawater was distilled and evaporated first to turn into simulated brine. Perchloric acid was then added into simulated brine to precipitate potassium perchlorate which could reduce the influence of potassium in the extraction procedure. After that, t-BAMBP and ammonia were separately used as extractant and stripping agent in the extraction and stripping procedures to get rubidium hydroxide solutions and cesium hydroxide solutions. Subsequently, they reacted with ammonium carbonate to get rubidium carbonate and cesium carbonate. In a nutshell, this study shows the optimal parameters of pH value to precipitate potassium perchlorate. Besides, pH value in the system, the concentration of t-BAMBP and ammonia, organic phase/aqueous phase ratio (O/A ratio), reaction time, and reaction temperature in solvent extraction step were investigated to get high purities of rubidium carbonate and cesium carbonate.

Application of concentration-dependent HSDM to the lithium adsorption from brine in fixed bed columns

Adsorption of lithium ions from simulated brine using layered lithium-aluminum hydroxides was investigated at 303 K in fixed-bed columns. The lithium adsorption isotherms in simulated brine were conducted using batch system, and the Langmuir isotherm model was found to fit the equilibrium data well. The effects of initial lithium concentration (C0, 200–400 mg/L), bed height (H, 30–200 cm), and feed flow rate (Q, 6–18 mL/min) on lithium breakthrough curves in packed bed columns were investigated systematically. In order to simulate the practical operation process, the breakthrough time was defined when the lithium recovery rate dropped down to 0.6. The column adsorption performance was improved with the increasing of bed height and the decreasing of the initial lithium concentration, feed flow rate. Furthermore, the Homogeneous Surface Diffusion Model (HSDM) with concentration-dependent surface diffusion coefficient was developed to simulate and predict the lithium adsorption curves. The numerical model results showed good agreement with the experimental data in simulated brine and factual brine circumstance, which proved that the model could successfully simulate the column adsorption process of lithium recovery. These results provided important information to design, optimize and scale-up the column adsorption process for lithium recovery from brine.

Lithium extraction from brine in an ionic selective desalination battery

With the increasing global demand for lithium, lithium extraction from seawater/brine attracted extensive attentions. Selective lithiation desalination battery is a novel and promising model for this process since its good performances on selectivity, extraction capacity and energy consumption. However, multi-metal composition and possible corrosiveness of seawater/brine requires high capacity electrode with high selectivity and cycle stability. To address this issue, this work proposed a less layer graphene gauze modified Ni-rich cathode material LiNi0.6Co0.2Mn0.2O2 core-shell structure microsphere (rGO/NCM) with shell thickness of 3 nm. The graphene gauze offers high electron transfer pathways instead of ion transfer between lattices, which reduced the NCM lattice collapse probability effectively. This was verified by ex-situ XRD and electrochemical results of high capacity, good cycle stability and rate performance in both organic and aqueous systems. In the desalination battery composed of rGO/NCM as positive and activated carbon (AC) as negative, rGO/NCM//AC delivered high Li+ extraction efficiencies reaching 13.84 mg/g per 1 cycle in simulated brine by consuming only 1.4 Wh/mol Li+. The overall process produced 93% Li+ in simulated brine at optimized operating conditions. The results indicated that rGO/NCM//AC desalination battery is a promising electrochemical lithium extraction approach.

Polymer nanoparticles based nano-fluid for enhanced oil recovery at harsh formation conditions

The application of nano-fluids for enhanced oil recovery (EOR) has attracted noticeable attention and has formed a new research area in recent years. Currently the great challenge for this area is to formulate a stable nano-fluid for oil reservoirs with high-temperature and high-salinity, in particular, when divalent ions are present. In this paper, a novel nano-fluid was developed by using nano-composite formed with polymer nanoparticles (PolyNPs) and a betaine-type zwitterionic surfactant. The developed nano-composite was characterized using electron microscopies (TEM and SEM), Fourier transform infrared (FTIR) spectrometry, dynamic light scattering (DLS), etc. The nano-fluid showed noticeable stability at relatively high salinity (15 wt% simulated brine) and high temperature (80 °C) for more than 30 days. The potential of the nano-fluid in recovering oil was evaluated by investigating the interfacial tension with Bakken oil and the oil contact angle in the nano-fluid. The results showed that the water–oil interfacial tension of the Bakken crude oil decreased by 99.49% and the contact angle increased by 125.73% compared to the original values. Then, the EOR efficiency of the nano-fluid was tested using Berea rocks saturated with Bakken crude oil through core flooding experiments. The results showed that the total oil recovery by nano-fluid is 9.32% higher than that of the control. Finally, the possible mechanism of the nano-fluid for EOR was proposed based on the investigation of dynamic displacing processes. The results demonstrated that the developed nano-fluid is a highly promising oil displacement agent for enhanced oil recovery.

Semi-continuous electrochemical extraction of lithium from brine using CF-NMMO/AC asymmetric hybrid capacitors

Compared to traditional extraction of lithium using solar evaporation, the electrochemical extraction is advantageous in many aspects, including elevated efficiency, superior selectivity, and low environmental pollution. In this study, LiNi0·038Mo0·012Mn1·95O4 (LNMMO) with good lattice structure and nano morphology was successfully prepared and confirmed by XRD (X-ray diffraction), SEM-Mapping (scanning electron microscope mapping), SEM (scanning electron microscope), and EDX (Energy-dispersive X-ray spectroscopy) analyses. The pairing of LNMMO with activated carbon (AC) yielded obvious cost-effective and environmentally friendly composite when compared to conventional Noble metals used for battery anodes, such as Ag and Pt. A hybrid supercapacitor was assembled using delithiated LNMMO cathode (NMMO) and AC anode to form NMMO/AC. The cell showed high capacity, high rate performance, and excellent cyclic stability. A continuous flow NMMO/AC hybrid supercapacitor (CF-NMMO/AC) was developed for selective capture of Li+ in aqueous solution by combining NMMO/AC hybrid supercapacitor with self-designed continuous flow control system. The device delivered high Li+ extraction efficiencies reaching 14.4 mg/g per one cycle in simulated brine by consuming only 7.91 W h/mol Li+. The overall process produced 97.2％ Li+ in simulated brine at optimized operating conditions. Overall, CF-NMMO/AC system provided higher efficiency, superior selectivity, and moderate energy utilization for Li+ recovery from brine.

Effect of propylene glycol substituted group on salt tolerance of a cationic viscoelastic surfactant and its application for brine-based clean fracturing fluid

In this study, a cationic viscoelastic surfactant (VES) called N-erucamidopropyl-N, N-dimethyl-N-(1, 2)-propylene glycol ammonium chloride (EDPG) with an unsaturated erucyl amide (C25) tail and a propylene glycol group was developed, which has an ultra-high salt tolerance compared to that of UC22AMPM. As with the zwitterionic VES of EDAS, EDPG molecules can aggregate into wormlike micelles (WLMs) in high-salinity solutions (above 10 wt% NaCl concentration) to impart viscoelasticity to the solutions, and their production cost is comparatively low. The surface tensions of EDPG and EDAS were measured in deionized water and salinity solutions to study the surface activities and the packing parameters (P) as functions of salinity, and the results showed completely different mechanisms regarding the salt tolerances of EDPG and EDAS. The propylene glycol group imparts a larger initial equilibrium area per molecule on the aggregate surface (a0) of EDPG, which can keep the P between 1/3 and 1/2 under ultra-high-salinity conditions to ensure the presence of WLMs. However, the salt tolerance of EDAS is attributed to its insensitivity to salinity because it is a zwitterionic betaine VES. The aggregation behavior of EPDG, EDAS, and UC22AMPM and the viscoelastic properties and microstructures of the EDPG solutions as functions of salinity were investigated using DLS, NMR, cryo-SEM, and oscillatory measurements to further confirm the salt tolerance of EDPG. Additionally, brine-based clean fracturing fluids prepared using EDPG and simulated brines exhibited good performance that meets the requirements of hydraulic fracturing fluid, according to a series of laboratory evaluation.

Study on a Polymer Profile Control Agent with Controllable Swelling Time

The study provided a microsphere profile control agent, which can smoothly go deep into the stratum by using the hydrophobic shell structure as the “protective film”. While the solution time in simulated brine was prolonged, water molecules went deep into the inside of the microsphere particles through the pore structure, and combined with hydrophilic groups. Because of the combination, the microsphere polymer started to swell, and opened the shell into long chain for days, and then at the end, its hydrophilic-hydrophobic block groups were all exposed in the solution, which resulted in self-thickening property. The dissolution time after entering into the stratum, i.e. the shell “rupture” time can be controlled by adjusting the carbon chains length of hydrophobic groups in the synthetic process. The agent can not only prolong the depth of plugging and provide a stable plugging rate, but also enlarge the water swept volume after dissolution. This method can stabilize the oil production and control the water cut. The function of delayed thickening ability makes the stratum sealed but kept at a certain permeability.

Removal of heavy metals by aged zero-valent iron from flue-gas-desulfurization brine under high salt and temperature conditions.

To achieve zero liquid discharge, the flue-gas-desulfurization (FGD) wastewater at coal-fired power plants can be concentrated into brine through thermal evaporation to maximize water reuse; however, the hot brine generated requires further treatment prior to disposal. To address this need, this study investigates the performance of aged, micron-sized zero-valent iron (ZVI) for heavy metal removal in simulated and real FGD hot brines, which was scarcely studied previously. The effects of temperature, pH, total dissolved solids, ZVI dosage, major cations, nitrate and sulfate on the reactivity of ZVI in the brines were evaluated. Among many factors, higher temperature and Mg2+ exert the dominant influence. At 80 °C, almost 100% of arsenate (1 mg/L) and chromate (1 mg/L) can be removed in <5 min using 4.17 g/L of ZVI in simulated brines, while selenate (25 mg/L) and cadmium (5 mg/L) can be completely removed within 30 min. Mg2+ ions naturally present in FGD brines account for the depassivation of aged ZVI. X-ray diffraction results suggest that green rust is the reactive intermediate for selenate and cadmium removal. Overall, this study demonstrates that ZVI is an effective material for removing heavy metals in hot FGD brines generated through thermal evaporation at power plants.

Highly Selective and Pollution-Free Electrochemical Extraction of Lithium by a Polyaniline/Lix Mn2 O4 Cell.

Conventional lithium extraction processes are inefficient or inadaptable for application in salt-lake brines with high Mg/Li ratios of ≥6. A new electrochemical cell, polyaniline (PANI)/Lix Mn2 O4 , was proposed to solve this problem for selective recovery of Li+ ions from brine water with high impurity cations (K+ , Na+ , Mg2+ , etc). Benefiting from the unique selectivity of spinel Lix Mn2 O4 for Li+ insertion and the high capacity of the PANI polymer for Cl- doping, this PANI/Lix Mn2 O4 cell could simultaneously extract LiCl from a simulated brine with a high average current efficiency of 95 %, an energy consumption of 3.95 W h molLiCl -1 , and a strong cycle ability with 70.8 % capacity retention over 200 cycles. In particular, this method avoids the use of additional chemicals, offering a highly efficient, pollution-free technology for Li+ extraction from brine waters.

Electrocoagulation for the purification of highly concentrated brine produced from reverse osmosis desalination of coal seam gas associated water

The ability of electrocoagulation (EC) at facilitating salt recovery from brine resultant from reverse osmosis (RO) desalination of coal seam gas (CSG) associated water is described. The aim was to reduce the presence of high concentrations of dissolved silicate which inhibit salt recrystallization by forming precipitates on equipment. The hypothesis was that EC could operate effectively in brine solutions and provide high silicate removal; thus facilitating a zero liquid discharge strategy. A benchtop EC unit equipped with either aluminium, iron or mixed iron-aluminium electrodes was used to treat simulated brine from a high recovery RO process. Up to 98.9% of silica was removed when aluminium or aluminium-iron electrodes were used. Significant reduction in concentrations of alkaline earth ions were also recorded (Ba > Sr > Ca > Mg) especially with iron electrodes. It appeared that silicate removal was via aluminosilicate formation. Hydraulic retention time was a key variable with 20 s recommended on the basis of performance/cost trade-off. Polarity reversal did not substantially change removal performance but impacted power consumption. For iron and iron-aluminium electrodes 1 min polarity reversal was preferred whereas for aluminium electrode 5 min was optimal. However, a thick coating was formed on the electrode surface and this may inhibit performance if longer tests are conducted. All flocs formed settled relatively rapidly (<20 min) which was in a time frame suitable for industrial application.

Preparation and characterization of porous HMO/PAN composite adsorbent and its adsorption–desorption properties in brine

Lithium-ion sieve (LIS) formation technology for Li+ recovery from seawater or brine is very important. In this article, the different types of H1.6Mn1.6O4 (HMO) composite adsorbents, including granular (HMO/PAN-G), nanofiber flat-sheet membrane (HMO/PAN-NM), flat-sheet membrane (HMO/PAN-FM), and hollow-fiber membrane (HMO/PAN-HFM) adsorbents, were prepared via the phase-inversion method using hydrophilic polyacrylonitrile (PAN) and Li1.6Mn1.6O4 (LMO) as the binder and precursor, respectively. The effects of the formation methods on the morphology, structure, and Li+ adsorption performance of the different types of HMO/PAN composite adsorbents were investigated. The adsorption performance of HMO/PAN-HFM was better than HMO/PAN-G and HMO/PAN-FM owing to its high porosity (88.1%). Results indicated that HMO/PAN-HFM (HMO = 50 wt%) exhibits optimal adsorption performance, with an optimum adsorption capacity of 18.1 mg g−1, corresponding to 91.4% of the adsorption capacity of HMO powder (19.8 mg g−1). Using Li+ solutions and simulated brine, the Li+ adsorption percentages were found to be 91.8% and 87.6%, respectively, at 12 h. The Li+ selectivity of HMO/PAN-HFM was 183–453 times those of other metal ions. These results indicate that PAN is an excellent carrier of HMO, and high-porosity HMO/PAN-HFM is promising as an LIS composite adsorbent.

Sustainable management of hypersaline brine waste: Zero liquid discharge via Joule-heating at supercritical condition

Supercritical water desalination is an increasingly attractive alternative treatment methodology for hypersaline brine (produced water) waste streams generated by oil/gas wells. The Joule-heating method provided in this study allows for internal heating of high conductivity fluids, reducing thermal lag and heat losses endemic to external heating methods. This study directly compares the aforementioned method for treating field-derived produced water from a Utica-Point Pleasant Shale well located in Noble County, Ohio with previous results using simulated brines. Experimental results from a prototype process are provided at operating pressures of 230 and 250 bar. At these pressures, a clean vapor was produced with total dissolved solids (TDS) levels of 608.73 ± 57.36 and 1174.52 ± 131.3 mg·L−1, respectively. The liquid outlet was processed through an additional flash vessel to assess further water recovery, producing an additional clean product with a TDS level of 618.0 ± 34.2 mg·L−1. A two-stage flash system model was assessed for the desalinator outlet, introducing a workable design for a zero liquid discharge (ZLD) system at all appropriate brine salt concentrations.