Brine Concentration Research Articles

Coordinated disposal of FGD gypsum and power plant concentrated brine via preparation of α-hemihydrate gypsum

α-hemihydrate (α-HH), known for its exceptional mechanical properties, is a widely used building material. Despite its advantages, the traditional method of producing α-HH through regular pressure brine poses significant drawbacks. These include substantial industrial salt demands, high production costs, and water pollution. A more environmentally friendly α-HH preparation process has been developed to counteract these issues, combining FGD gypsum and concentrated brine. This study delves into the effects of the principal ions present in concentrated brine on the phase transition process and the microstructure of the final product. Our findings reveal that the reaction rate accelerates with increased concentrations of Ca2+, Mg2+, K+, and Na+ in concentrated brine. However, excessive Na+ concentration can alter the phase transition process, converting the product to β-HH. Additionally, an overly high concentration of KCl may prompt a part of the K+ to engage in the reaction, leading to the formation of isomeric potassium gypsum. This process can disrupt the original structure of hemihydrate gypsum. The addition of maleic acid to the salt solution was found to foster anhydrous gypsum formation. In contrast, succinic acid can decrease the crystals' aspect ratio, resulting in the growth of short columns, thereby enhancing the product's strength performance. Our research also identified that the reaction rate elevates as the pH value declines. However, an acidic environment diminishes the size of the crystal and counteracts the crystal modifier's effects. Lastly, incorporating CaCl2 and MgCl2 into concentrated brine with a low Na+ concentration can convert FGD gypsum into high-strength α-HH. This transformation results in a product boasting a 1-day compressive strength of 40.5 MPa.

Solid-State Electrolyte for Lithium Extraction from Salt Lake Brines

Lithium sources are of great significance for developing the next generation of lithium ion batteries. Most of the world’s lithium sources are found in salt lake brines. The main challenge of lithium extraction from salt lake brine is the separation of lithium ions from other coexisting ions, especially the separation of Li+ and Mg2+. However, the traditional precipitation method for salt lake lithium extraction is cumbersome. In this project, a new electrolytic device with a solid-state electrolyte was developed for high-efficient lithium extraction from salt lake brines. Li1+xAlxTi2−x(PO4)3 (LATP) is a promising NASICON-type solid-state electrolyte, which exhibits high ionic conductivity ( >10-4 S/cm) at room temperature. LATP can be used as a lithium ion conductor, that is only lithium ions can transfer through it, which is ideal for separating lithium ions from other ions in salt lake brines. In this project, high-quality LATP was fabricated at a low cost. An electrolytic device was developed for lithium extraction, in which LATP was used together with a sacrificial anode, molten salts, and an inert cathode. Salt lake brines need to be concentrated by solar and/or wind evaporation before lithium extraction. The electrolytic device was operated above the melting point of the concentrated brine water, at which LATP exhibits a higher ionic conductivity for fast lithium ion transfer. A tiny voltage was applied across the two electrodes to drive the electrochemical reaction. The composition of lithium sources before and after extraction was investigated by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Results show that lithium sources with a higher purity level were successfully extracted with high efficiency. Impurity ions were almost completely blocked by LATP.

An unusual case of low concentration mineral brines in the geothermal waters from Beiuș Basin (Northwestern Romania)

The aim of the BrineRIS project is to explore brines in RIS countries potential for critical metal extraction In the frame of this project the concentration of mineral brines in three geothermal wells located in the Beiuș Basin (northwestern Romania) was determined by analyzing the water from the wells. Until recently no reliable trace element data were available from Beiuș basin. Following the new analyses, the geothermal water extracted by TRANSGEX SA company from wells F-3001H, F-3003H, and F-3005H revealed exceptionally low concentrations of associated chemical compounds. The Li-concentration is only ~ 22 – 32 µg/l. Zn, I, Rb and As present in similar concentrations, while other trace elements (e.g. Co, V, Ti) are below detection limit. The Sr (~ 540 – 680 µg/l), Ba (~ 170 – 200 µg/l) and B (~ 70 – 100 µg/l) concentrations are slightly elevated, but still low. Therefore, the water in this "geothermal reservoir" can be classified as relatively potable, but it is not appropriate for critical metal extraction. In this paper, some documented concentrations from previous years have been compared to recent concentrations. In addition, the relationship between geology and water chemistry is emphasized in order to determine the reason for the absence of solutes that were expected to be found in this water.

Contrasting sources and enrichment mechanisms in lithium-rich salt lakes: A Li-H-O isotopic and geochemical study from northern Tibetan Plateau

Lithium (Li), a crucial mineral resource for modern high-tech industries, is notably abundant in the northern Tibetan Plateau, primarily within lithium-rich salt lakes. However, the exploration and development of these resources are hindered due to an incomplete understanding of their nature and origin. Here we present results from a comprehensive study on the hydrochemical parameters, whole-rock geochemistry, H-O isotopes, and Li concentrations in surface brine, river water, geothermal springs, and associated rocks from two representative lithium-enriched salt lakes, the Laguo Co (LGC) and Cangmu Co (CMC) in Tibet to understand the genetic mechanisms. Our water-salt balance calculations and H-O isotopic analysis reveal that Li in LGC and CMC primarily originates from the Suomei Zangbo (SMZB, ∼91%) and Donglong Zangbo (DLZB, ∼75%) rivers, respectively. It is estimated that the LGC and CMC took a minimum of 6.0 ka and 3.0 ka to accumulate their current lithium resources, respectively. The distinct geological characteristics reflect evolutionary differences between the two lakes, suggesting diverse lithium sources and enrichment processes. The high lithium ion concentration and light lithium isotope composition in the SMZB river waters indicate the genetic relationship with lithium-enriched geothermal springs in the Tibetan Plateau. Our results suggest that lithium in the LGC originates from lithium-enriched geothermal springs and is primarily supplied through the small-scale SMZB river. In contrast, the formation and evolution of CMC are influenced by the northern Lunggar rifts, receiving a prolonged and stable input from the DLZB, resulting in high lithium concentrations and isotopic values. The absence of lithium-enriched geothermal springs and the prevalence of silicate rocks in the CMC catchment suggest that lithium may be sourced from the weathering of silicate rocks, such as granitic pegmatite veins containing lithium-rich beryl, widely distributed in the upstream area of DLZB. The forward modeling approach, quantifying the contribution fractions of different reservoirs (atmospheric precipitation, silicate, carbonate, and evaporite), indicates that the distinct lithium concentrations in the mainstream (>1 mg/L) and tributaries (<0.1 mg/L) are positively correlated with the ratio of silicate contributions to carbonate contributions, suggesting that dissolved lithium in river waters primarily originates from the weathering and dissolution of silicate rocks. The distinct sources and enrichment mechanisms of lithium in these two salt lakes are attributed to various evolutionary processes, topographical features, hydrological factors, fundamental geological settings, and tectonic histories, despite their spatial proximity. Furthermore, our study highlights the significant role of rivers in the formation of young salt lakes, in addition to geothermal springs.

Concentrate circularity: A comparative techno-economic analysis of membrane distillation and conventional inland concentrate management technologies

Inland desalination with reverse osmosis (RO) offers a promising alternative to increase potable water resources. However, large volumes of concentrated brine are generated as a byproduct of the process. Concentrate disposal for inland regions displaces valuable water resources and can make up to 33 % of the total cost of desalination. Conventional disposal systems are limited by location, hydrogeology, climate, and policies, and few place value on resource recovery, thus limiting the implementation of desalination facilities in water-stressed regions. Membrane distillation (MD) is an alternative technology that can minimize disposal volume while maximizing water recovery for beneficial reuse. MD uses thermal energy gradients to desalinate the concentrate stream achieving near zero-liquid discharge. Furthermore, several MD configurations include heat recovery, making MD an energy-efficient alternative. A techno-economic assessment (TEA) of air-gap MD (AGMD) for RO concentrate management was performed and compared to three conventional concentrate management systems: evaporation ponds, deep-well injection (DWI), and concentration-crystallization. TEA results indicate that compared to DWI at 1.09 $/m3, evaporation ponds at 1.47 $/m3, and concentrators at 6.2 $/m3, respectively, AGMD is a competitive concentrate management technology producing water at 0.90 $/m3 when operating conditions are optimized and low-grade heat is available. When operating at high salinity (>70 g/L) the selection of operating conditions, specifically module length and circulating flowrate, is critical. Results of this study support the economic viability of AGMD in contrast to current industry standards and highlight the importance of resource recovery to promote a circular water-energy economy for regions relying on reuse and desalination.

Influence of internal design on the performance of pilot vacuum-assisted air-gap membrane distillation modules for brine concentration with solar energy

Membrane distillation (MD) in batch operation is proposed for brine concentration with solar energy in zero liquid discharge (ZLD) desalination processes, but there are some research gaps yet. Energy efficiency is key for implementing the technology with solar energy and there is not enough experience and experimental results of operation of MD pilot modules at high salinity feeds. This research focuses on the experimental evaluation and comparison of two multi-envelope spiral wound commercial membrane distillation modules operating in vacuum-assisted air gap MD at the solar MD pilot facilities of Plataforma Solar de Almería in Spain. These modules have similar membrane area (24 and 25.9 m2) and residence time (large, to maximize thermal efficiency), but different internal design: 6 envelopes 5 m long and 12 envelopes 2.7 m long, respectively. This difference affects mostly the feed circulation velocity for equal feed flow rate. Performance parameters such as permeate production and specific thermal energy consumption (STEC) are compared and experimental models performed and validated for different feed salinities. Permeate quality and specific electrical energy (SEEC) consumption are also evaluated. The results show that the best module for batch operation is the one with a larger number of channels but of shorter length.

Construction of novel stable surface ion-imprinted graphene aerogels for efficient and selective extraction of lithium ion

Selective extraction of lithium from salt lake brine has attracted widespread attention in order to meet the growing global demand for lithium. Due to the high Mg2+/Li+ ratio and low Li+ concentration in salt lake brine, extracting Li+ from salt lake brine is extremely challenging. Herein, a novel approach was employed using graphene oxide (GO) with abundant functional groups as the skeleton material, and trihydroxymethyl aminomethane (Tris) as the pioneering reducing agent. Through the liquid phase self-assembly technology combined with surface modification, the Li+ imprinted three-dimensional block graphene aerogels (IDGAs) were successfully constructed under the assisted cross-linking effect of N,N-dimethylformamide (DMF). The IDGAs achieve good adsorption capacity (12.55 mg g−1), excellent regeneration performance, and comparatively high selectivity against Na+, K+, and Mg2+ of 4.75, 2.71, and 1.90, respectively. The exceptional properties of IDGAs can be attributed to the synergism resulting from the establishment of adsorption sites through the high specific surface area of the skeleton, as well as the selective recognition of Li+ by 2-hydroxymethyl-12-crown ether-4. Consequently, IDGAs represent a highly promising option for the efficient extraction of lithium from salt lake brine.

Produced-Water Desalination Approach Uses Renewable Thermal Energy

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 211175, “An Innovative Method of Water Management by Desalinating Produced Water Using Thermal Renewable Energy,” by Sharifa M. Al-Ruheili, Felix Tiefenbacher, and Khansaa H. Almahrami, ARA Petroleum Exploration and Production, et al. The paper has not been peer reviewed. _ The operator is adopting a method to manage high-salinity produced water in an environmentally sustainable way by extracting potable water from produced water and reducing discharge water volume by at least 50%. For desalination of the produced water, a combination of forward and direct osmosis technology is used. This process is driven mostly by thermal energy, which is provided to thermal collectors that are 100% solar. This technology uses renewable energy and will have no carbon footprint. Technology Description The technology involves concentrated solar thermal (CST) power plants that provide 100% renewable water desalination. Forward osmosis (FO) and direct osmosis (DO) can desalinate highly saline and polluted water, such as produced water, mainly with solar thermal energy. A pneumatic solar thermal plant consisting of two HELIOtube collectors, each 121 m long, provides the thermal energy for the desalination process. The plant includes a mirror technology based on CST, a cost-effective heat-transfer system using pressurized water as heat transfer fluid (HTF), and a low-maintenance thermal energy storage (TES) system allowing nighttime operations of 35 m3 volume with an operating temperature of 180°C using a pressurized water tank at 10-bar operating pressure. The desalination system will contain a pretreatment unit for the produced water and a desalination (FO) and brine-concentration (DO) unit. The unit will be integrated with thermal power to operate the desalination plant. In addition, a fully automated control system with a live backup will be installed. The system is classified as having low maintenance and cleaning costs because of its encapsulation features, rotatability of 300°, and convex shape. Fig. 1 of the complete paper shows the planned plant layout. The desalination plant will feature two outputs: fresh water of potable quality and brine. The fresh water will be used to serve the company’s freshwater demand, with excess water used for agricultural purposes or mixed with water in an injector well to improve injectivity. The other output, the highly concentrated brine (20% salt), will be collected in the existing evaporation pond where two main research and development studies are ongoing, one related to mineral extractions and the second related to salt monetization (using salt as a drilling additive).

Multi-well combined solution mining for salt cavern energy storages and its displacement optimization

Improving the water solution mining rate of the salt rock layer while reducing energy consumption is the core idea for promoting the construction of salt cavern energy storage. In this work, a novel multi-well combined solution mining method for salt cavern energy storages was presented, and a displacement optimization model incorporating sub-models for outlet brine concentration, solution mining rate, and energy consumption of water injection was proposed to maximize the solution mining efficiency. The accuracy of the proposed model is verified by comparing the simulated results with the field data. The results show that under basically the same solution mining rate, the energy consumption of brine injection can decrease by 18.82 %. If 0.49 % of the solution mining rate of the salt cavern can be sacrificed, energy consumption can be reduced by 7.40 %. A special focus was given to the well selection schemes, which indicated that optimization of well selection schemes could reduce energy consumption by 3.61 %. This work could add further insights into the inter-coupling relationship between outlet brine concentration, solution mining rate, and energy consumption of water injection, and help to reduce the energy consumption of water injection and improve solution mining rate.

Biomass-derived 3D evaporator with antifouling and salt-rejecting toward solar-enabled steam generation, desalination, and electricity generation

Solar-driven interfacial evaporation is currently considered as one of the most effective and sustainable strategies to address water scarcity and energy shortages issues. Whereas, challenges in developing durable, eco-friendly, and low-cost solar evaporators from readily available materials still exist. Herein, we have reported a facile strategy to construct a robust natural sorghum stalk pith solar evaporator. With advantageous features of gradient honeycomb structure and hydrophilic polymer chains, the constructed evaporator exhibits broadband light absorption, efficient light to heat conversion, fast water transport, and multi-channel release of steam performances, leading to an ultrahigh evaporation rate of 3.79 kg m−2h−1 under one sun irradiation and outstanding salt-resistant ability at a high evaporation rate of 2.6 kg·m−2·h−1 in a highly concentrated brine (20 wt% NaCl), accompanied with anti-oil-fouling performances, as well as high oil removal efficiency (>99.8 %) for oil-in-water emulsion, outperforming most previously reported solar evaporators. Additionally, solar irradiation can further promote the directional water flow, contributing to a high photovoltage of 68 mV under one sun illumination. This paves the way for designing durable biomass-based steam generators, not only scaling up sustainable clean water production, sewage depuration and desalination, but also discovering promising application in the field of electricity generation.

Stochastic inactivation evaluation of foodborne pathogens during ohmic heating of poultry meat

Abstract The objective of this study is to stochastically assess the inactivation probabilities of four common foodborne pathogens (Listeria, Salmonella, Escherichia coli, and Campylobacter) in chicken meat during ohmic heating (OH) in a salt solution. A mechanistic model was used to accomplish this, coupling heat transfer, laminar fluid flow, and the electric field, and solved numerically using COMSOL Multiphysics® v5.6. The 3D model represented 1000 particles randomly placed on the meat’s surface to determine the 7-log reduction of bacterial load probability. These particles are virtual representatives of bacterial colonies in the model. The influence of uncertain input parameters (specific heat capacity and electrical conductivity) and OH conditions (salt concentration of the heating medium, applied voltage, and heating time) was explained using logistic regression. The same analysis was repeated for the slowest heating point of chicken meat, as well. According to the findings, cold spots are observed at the corners of the meat piece during OH, requiring additional attention to the meat surface temperature to prevent under-processing. Sensitivity analysis revealed that the applied voltage and brine concentration are the main factors affecting the inactivation probabilities of pathogenic bacterial cells on the chicken meat surface. Salmonella and Listeria may require higher electrical conductivity of chicken meat and longer processing times. The developed model enables predicting inactivation probabilities of microorganisms that can be found on the outer surface by measuring the core temperature of the meat. However, especially for bacteria with higher heat resistance, it is better to consider the cold spot temperature found in the corners of the food material during OH.

The impact of CO2 saturated brine salinity on wormhole generation and rock geomechanical and petrophysical properties

Deep saline aquifers are good candidates for CO2 sequestration because of their huge reserves, wide distribution, cost-effectiveness, and relatively high security. The impact of CO2 sequestration on the rock's mechanical and petrophysical properties is a complex issue that depends on a number of factors, such as salinity. This study provides insights into the potential changes in rock petrophysical and geomechanical properties due to the reactivity of CO2-saturated brine with limestone. Specifically, this article provides insights into the impact of salinity on wormhole generation and the corresponding changes in rock properties. Three Indiana limestone samples with a 1.5-inch diameter and 3-inch length, 15% average porosity, and 2 mD average permeability were used. The samples were flooded at 1 mL/min, 2000 psi, and 60 °C with different brine concentrations mixed with CO2 at a 70:30 ratio. To examine the impact of salinity, CO2 was mixed with brine concentrations of 40,000 ppm, 120,000 ppm, and 200,000 ppm for the coreflooding experiments. The samples' Young's modulus (YM) and Poisson's ratio at different confining pressures were measured before and after coreflooding. A medical CT scan was also used to visualize the generated wormholes and quantify their volumes. Results showed that it took only 14.3 pore volumes (PVs) to create a wormhole at 40,000 ppm, while 24.8 and 25.6 PVs at 120,000 ppm and 200,000 ppm, respectively. Lower salinity live brine generated a thicker wormhole compared to the other salinities. The reduction in rock strength in terms of YMs was the highest at 200,000 ppm, followed by the 120,000 ppm and then the 40,000 ppm cases. This study demonstrates that wormhole generation can substantially increase CO2 storage capacity in low-salinity aquifers; however, an increase in CO2 relative permeability indicates that it will accumulate primarily beneath the caprock. In addition, this study reveals that fresh carbonated water or water with a low salinity can be used for acid stimulation.

Pilot plant evaluation of membrane distillation for desalination of high-salinity brines

Membrane distillation (MD) is a hybrid thermal-membrane desalination process that can use either low-grade waste heat and/or solar energy with hydrophobic membranes to desalinate high-salinity brines and produce high quality distillate. A research consortium was launched to investigate the application of the MD process, at lab and pilot scale, for desalination of concentrated brines. Bench scale results showed the presence of antiscalants in the concentrated brines minimized the scale precipitation potential and offered stable membrane permeability performance. Various MD technologies were screened, and two suitable technologies were selected for field-testing. Pilot unit A was based on multi-effect vacuum showed a stable flux of 6.2 LMH with excellent salt rejection (> 99.9%) from the concentrated brine discharged from thermal desalination plant in Qatar. That pilot unit was also field tested on hypersaline groundwater in Texas (USA) to generate fresh water for reservoir fracking in unconventional oil production operations. The MD unit was coupled with humidification/dehumidification (HDH) unit to achieve zero liquid discharge (ZLD) for inland applications. The MD unit was operated at 40% recovery producing distillate of < 20 mg/L total dissolved solids (TDS) and observed a stable flux of 5 LMH. Key challenges that are critical for large-scale deployment of MD technology were identified at the end of the field-testing program. Finally, a review of active MD technologies was conducted to highlight recent promising developments for full-scale applications.

Making Nanofiber Membrane Stand on End to Construct Vertically Interfacial Evaporators for Efficient Solar Evaporation, Omnidirectional Solar Absorption, and Ultrahigh-Salinity Brine Desalination.

Solar-driven interfacial desalination is widely considered to be a promising technology to address the global water crisis. This study proposes a novel electrospun nanofiber-based all-in-one vertically interfacial solar evaporator endowed with a high steam generation rate, steady omnidirectional evaporation, and enduring ultrahigh-salinity brine desalination. In particular, the electrospun nanofiber is collected into the tubular structure, followed by spraying with a dense crosslinked poly(vinyl alcohol) film, which renders them sufficiently strong for the preparation of a vertically array evaporator. The integrated evaporator made an individual capillary as a unit to form multiple thermal localization interfaces and steam dissipation channels, realizing zone heating of water. Thus a high steam generation rate exceeding 4.0kgm-2h-1 in pure water is demonstrated even under omnidirectional sunlight, and outperforms existing evaporators. Moreover, salt ions in the photothermal layer can be effectively transported to the water in capillaries and subsequently exchanged with the bulk water due to the strong action of capillary force, which ensures an ultrahigh desalination rate (≈12.5kgm-2h-1 under 3 sun) in 25wt% concentration brine over 300min. As such, this work provides a meaningful roadmap for the development of state-of-the-art solar-driven interfacial desalination.

Efficient lithium recovery from simulated brine using a hybrid system: Direct contact membrane distillation (DCMD) and electrically switched ion exchange (ESIX)

Seawater reverse osmosis (SWRO) brine is a readily available resource hub in many countries, fulfilling the country's freshwater need by SWRO, yet lower in a concentration of high-demand elements like Li. This study outlines developing a novel hybrid system that combines direct contact membrane distillation (DCMD) and electrically switched ion exchange (ESIX) to facilitate simultaneous SWRO brine enrichment followed by selective Li recovery. The DCMD process concentrates the SWRO brine utilizing electrospun nanofiber membranes (ENMs) composed of polyvinylidene fluoride (PVDF). Incorporating reduced graphene oxide (rGO) nanoparticles augments the morphological, thermal, and mechanical stability of the PVDF ENMs. The water contact angle (WCA) of the 1-rGO/PVDF ENM stands at 142.08°, a testament to an enhanced hydrophobic property which resulted in a 12 % freshwater recovery from simulated SWRO brine and a 2.4-fold increase in Li+ concentration. The durability of the 1-rGO/PVDF ENM is evident in its minimal 11 % reduction in WCA after 15 h of brine concentration. In the context of hybrid operation, a Li-selective LiAlO2 electrode, coupled with an activated carbon counter electrode, demonstrated remarkable Li recovery for Li capture solutions enriched by the rGO-PVDF membrane in the DCMD phase. Compared to the Li concentration in the DCMD feed, sequential Li capture and release cycles recovered 91.8 % of Li, thereby underlining the critical role of the hybrid mode operation in concentrating Li from simulated brine solutions.

A novel slide-like cotton-based evaporator with gradient evaporation strategy for seawater resource acquirement

Solar-Driven Interfacial Evaporation (SDIE) is a promising green technology with great potential for seawater desalination. In this study, a novel slide-like cotton-based solar evaporator is designed using Carbon Nanotubes (CNTs) and Musou Black (MB) in an inclined mode, achieving a fast capillary force-induced gravity-assisted water transport. The evaporator achieved a stable desalination of the concentrated brine (10.0 wt% NaCl solution) at the evaporation rate of 1.44 kg m-2 h−1 under one simulated sunlight (1 KW m−2). Adequate water supply facilitated a superior self-cleaning property without salt aggregation at the evaporation surface and its periphery. In the 10-day long-term evaporation (3.5 wt% NaCl solution), a stable water evaporation rate (1.77 kg m-2 h−1) and a light-to-heat conversion efficiency (95.47%) were obtained without salt aggregation. The evaporation rate could even reach 1.88 kg m-2 h−1 in a closed evaporation system outdoors under the practical light. Then, the gradient evaporation strategy was applied by combination of the slide-like solar evaporator consecutively in three stages, in-between which two collection tanks for the concentrated seawater were present. As the concentrated seawater can be used to extract Li, Mg, etc., and the mineral salts of the sea can be used for nutrients, bathing products, etc., the gradient evaporation strategy has realized the simultaneous derivation of the condensed pure water, the concentrated seawater with different concentrations, and the mineral salts at the last stage as industrial raw materials. This study provides new insights into the design of high-efficiency solar evaporators that can comprehensively realize the utilization of seawater resources.

Large-scale preparation of UV photo-crosslinked composite membrane with high pervaporation desalination properties and excellent fouling resistance

In this study, we developed a high-performance composite membrane with rapid cross-linking and large-scale technology for PV desalination. Some strategies were adopted to achieve this purpose. First, photo cross-linking was used to shorten the cross-linking time of PVA within 60 s. Second, a PTFE microfiltration membrane was utilized as the substrate that mitigated the transport resistance of the supporting layer. Third, an large-scale spray-coating device was built-up which completed the amplification preparation of composite PV membrane. Finally, ZIF-8 nano-particle was introduced into the PVA layer that increased the free volume and amorphous region of PVA, enhancing the water flux of membrane. When desalted a 3.5 wt% NaCl solution at 80 °C, a water flux of 307.58 ± 15.09 kg/m2·h was achieved for the PVA/ZIF-8/PTFE composite membrane. To better reflect the membrane performance, the permeance of PVA/ZIF-8/PTFE membrane was also calculated, which was reached to 674.37 kg/m2 h bar, exceeding 18.4% than the highest reported property of PVA/PAN nanofiber membrane (569.55 kg/m2 h bar). In addition, the composite membrane showed stable water flux and salt rejection when treating highly concentrated brine solution containing organic pollutant. When desalinated a 10 wt% NaCl solution with 1 wt% HA at 80 °C, the PVA/ZIF-8/PTFE membrane produced water with low conductivity of 15.78 μs/cm and a high water flux of 129.95 kg/m2·h in a period of 180 min.

Relationships between Na, K, and Ca mineral nutrients in brine and table olive flesh. Nutritional labelling implications

The mineral equilibrium between olive flesh/moisture (in-flesh) and the surrounding brines has been studied for the first time. A pseudo-distribution coefficient, Kd, has been defined and applied to fermented Gordal, Manzanilla (green Spanish-style) and packaged Aloreña de Málaga (natural green) olives. Kd had values < 1 for Na and K in the flesh but >1 for Ca, suggesting lower and higher contents in olive flesh than in brine. When the equilibrium for Na and K was referred to the flesh moisture, most Kd approached 1, implying a trend for equilibrium. However, Ca exhibited values above 1, indicating a higher concentration also in the flesh moisture, suggesting that part of this element may also form complexes with soluble olive flesh components. Kd was not significantly related to the concentrations of Na, K, or Ca in brines, although the Na model explained 80% variance. Simple and multiple regressions deduced the mineral nutrients in the flesh as a function of their concentrations in brine, but the second only increased the explained variance (about 10%) in the case of Na. For nutritional labelling purposes in the EU (where sodium must be expressed as salt), both functions can estimate the Na, K, and Ca contents in olive flesh from their concentrations in brine since their variabilities were within tolerance limits, particularly when the initial fermentation/packaging brines were fortified with K or Ca.

Reservoir Drilling and Openhole Gravel Packing with High-Density Cesium Formate Fluids in a High-Pressure, Marginal Mud Window Environment at Martin Linge

Summary High-density cesium/potassium (Cs/K) formate fluids were successfully utilized from reservoir drilling to upper completion installation in five productive Martin Linge high-rate gas wells. Four wells were completed with openhole gravel pack (OHGP) and one with standalone sand screens. The gravel packing operation marks what is considered to be the highest density carrier fluid OHGP successfully completed worldwide, with a specific gravity (SG) of 2.06. A complex operation under pressure and temperature conditions (745–780 bar and 135–140°C) that almost qualify as high pressure/high temperature (HP/HT), including managed pressure drilling (MPD), overbalanced screen running, and openhole gravel packing, was simplified by using the same base brine throughout the operation. Cs/K formate reservoir drilling fluid (RDF) and screen-running fluid were designed with biopolymeric additives and minimal calcium carbonate bridging particles. Clear Cs/K formate brine was chosen as gravel pack (GP) carrier fluid. The use of Cs/K formate fluids for all stages of the operation reduced the complexity of transitioning between the operational stages. In addition, the reservoir was only exposed to one filtrate without application of damaging weighting solids. The drilling fluid contributed to successful MPD and delivered wells with very good hole quality in the reservoir, which consisted of interbedded sandstone, coal stringers, and shale. The shale-stabilizing properties of concentrated formate brine–based fluids provided acceptable conditions for extended openhole time and allowed additional logging runs, including pore pressure measurements, under near-HP/HT conditions, before running the screens. One bottom-up cleanout was conducted before the screen-running fluid was circulated in and the screens installed. The spurt and seepage losses were low throughout the drilling and screen-running phases. No breaker treatment was required in any of the wells. All wells have proved to have good initial productivity and high well productivity index. The successful OHGP operations performed with the high fluid densities required in Equinor’s Martin Linge field have set a new standard for well completions in challenging high-pressure environments.

Evaluating Corrosion Resistance of Metal Materials in Fire Productsvia Saltwater Spray Test Under Various Experimental Conditions

The brine concentration and salt spray time of KS D 9502, a saltwater spray test commonly used in Korea, were used to experimentally confirm the corrosion in iron, copper and stainless steel, and the degree of corrosion in fire extinguishers, automatic diffusion extinguishers, and residential automatic extinguishers. The results of the KS D 9502 brine spray test confirmed that there was little difference between iron and stainless under all test conditions, and that the results of the salt water test for copper were nearly identical to those of 5 wt% and 240 h (10 cycles). Unlike the two previous sets of conditions, the test results obtained at 5 wt% and 120 h of saltwater of the raw material showed very few visual (qualitative) and weight (quantitative) changes in corrosion, rendering these conditions unsuitable for the saltwater spray test. The saltwater spray tests in the fire extinguisher, automatic diffusion fire extinguisher, and residential automatic fire extinguisher showed that the results obtained at 5 wt% salt water and 240 h (10 cycles) and those obtained at 20 wt%, 240 h were nearly identical. These experimental studies show that the saltwater spray test of KS D 9502 is a variable in the corrosion resistance test, in which the time of the saltwater spray test is more important than the saltwater concentration.