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The Role of Operating Conditions in the Precipitation of Magnesium Hydroxide Hexagonal Platelets Using NaOH Solutions. CRYSTAL GROWTH & DESIGN 2023; 23:6491-6505. [PMID: 37692336 PMCID: PMC10485817 DOI: 10.1021/acs.cgd.3c00462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 07/25/2023] [Indexed: 09/12/2023]
Abstract
Magnesium hydroxide, Mg(OH)2, is an inorganic compound extensively employed in several industrial sectors. Nowadays, it is mostly produced from magnesium-rich minerals. Nevertheless, magnesium-rich solutions, such as natural and industrial brines, could prove to be a great treasure. In this work, synthetic magnesium chloride and sodium hydroxide (NaOH) solutions were used to recover Mg(OH)2 by reactive crystallization. A detailed experimental campaign was conducted aiming at producing grown Mg(OH)2 hexagonal platelets. Experiments were carried out in a stirred tank crystallizer operated in single- and double-feed configurations. In the single-feed configuration, globular and nanoflakes primary particles were obtained, as always reported in the literature when NaOH is used as a precipitant. However, these products are not complying with flame-retardant applications that require large hexagonal Mg(OH)2 platelets. This work suggests an effective precipitation strategy to favor crystal growth while, at the same time, limiting the nucleation mechanism. The double-feed configuration allowed the synthesis of grown Mg(OH)2 hexagonal platelets. The influence of reactant flow rates, reactant concentrations, and reaction temperature was analyzed. Scanning electron microscopy (SEM) pictures were also taken to investigate the morphology of Mg(OH)2 crystals. The proposed precipitation strategy paves the road to satisfy flame-retardant market requirements.
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2
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Energetic Valorisation of Saltworks Bitterns via Reverse Electrodialysis: A Laboratory Experimental Campaign. MEMBRANES 2023; 13:293. [PMID: 36984679 PMCID: PMC10059069 DOI: 10.3390/membranes13030293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Concentrated bitterns discharged from saltworks have extremely high salinity, often up to 300 g/L, thus their direct disposal not only has a harmful effect on the environment, but also generates a depletion of a potential resource of renewable energy. Here, reverse electrodialysis (RED), an emerging electrochemical membrane process, is proposed to capture and convert the salinity gradient power (SGP) intrinsically conveyed by these bitterns also aiming at the reduction of concentrated salty water disposal. A laboratory-scale RED unit has been adopted to study the SGP potential of such brines, testing ion exchange membranes from different suppliers and under different operating conditions. Membranes supplied by Fujifilm, Fumatech, and Suez were tested, and the results were compared. The unit was fed with synthetic hypersaline solution mimicking the concentration of natural bitterns (5 mol/L of NaCl) on one side, and with variable concentration of NaCl dilute solutions (0.01-0.1 mol/L) on the other. The influence of several operating parameters has also been assessed, including solutions flowrate and temperature. Increasing feed solutions' temperature and velocity has been found to lower the stack resistance, which enhances the output performance of the RED stack. The maximum obtained power density (corrected to account for the effect of electrodic compartments, which can be very relevant in five cell pairs laboratory stacks) reached around 10.5 W/m2cellpair, with FUJIFILM Type 10 membranes, temperature of 40 °C, and a fluid velocity of 3 cm s-1 (as empty channel, considering 270 μm thickness). Notably, the present study results confirm the large potential for SGP generation from hypersaline brines, thus providing useful guidance for the harvesting of SGP in seawater saltworks all around the world.
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Electrodialysis with Bipolar Membranes for the Sustainable Production of Chemicals from Seawater Brines at Pilot Plant Scale. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2023; 11:2989-3000. [PMID: 36844752 PMCID: PMC9945178 DOI: 10.1021/acssuschemeng.2c06636] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 01/30/2023] [Indexed: 06/18/2023]
Abstract
Environmental concerns regarding the disposal of seawater reverse osmosis brines require the development of new valorization strategies. Electrodialysis with bipolar membrane (EDBM) technology enables the production of acid and base from a salty waste stream. In this study, an EDBM pilot plant with a membrane area of 19.2 m2 was tested. This total membrane area results much larger (i.e., more than 16 times larger) than those reported in the literature so far for the production of HCl and NaOH aqueous solutions, starting from NaCl brines. The pilot unit was tested both in continuous and discontinuous operation modes, at different current densities (200-500 A m-2). Particularly, three different process configurations were evaluated, namely, closed-loop, feed and bleed, and fed-batch. At lower applied current density (200 A m-2), the closed-loop had a lower specific energy consumption (SEC) (1.4 kWh kg-1) and a higher current efficiency (CE) (80%). When the current density was increased (300-500 A m-2), the feed and bleed mode was more appropriate due to its low values of SEC (1.9-2.6 kWh kg-1) as well as high values of specific production (SP) (0.82-1.3 ton year-1 m-2) and current efficiency (63-67%). These results showed the effect of various process configurations on the performance of the EDBM, thereby guiding the selection of the most suitable process configuration when varying the operating conditions and representing a first important step toward the implementation of this technology at industrial scale.
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Analysis of Operational Parameters in Acid and Base Production Using an Electrodialysis with Bipolar Membranes Pilot Plant. MEMBRANES 2023; 13:200. [PMID: 36837703 PMCID: PMC9965870 DOI: 10.3390/membranes13020200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/25/2023] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
In agreement with the Water Framework Directive, Circular Economy and European Union (EU) Green Deal packages, the EU-funded WATER-MINING project aims to validate next-generation water resource solutions at the pre-commercial demonstration scale in order to provide water management and recovery of valuable materials from alternative sources. In the framework of the WATER-MINING project, desalination brines from the Lampedusa (Italy) seawater reverse osmosis (SWRO) plant will be used to produce freshwater and recover valuable salts by integrating different technologies. In particular, electrodialysis with bipolar membranes (EDBM) will be used to produce chemicals (NaOH and HCl). A novel EDBM pilot plant (6.4 m2, FuMa-Tech) has been installed and operated. The performance of EDBM for single pass under different flowrates (2-8 L·min-1) for acid, base and saline channels, and two current densities (200 and 400 A·m-2), has been analyzed in terms of specific energy consumption (SEC) and current efficiency (CE). Results showed that by increasing the flowrates, generation of HCl and NaOH slightly increased. For example, ΔOH- shifted from 0.76 to 0.79 mol·min-1 when the flowrate increased from 2 to 7.5 L·min-1 at 200 A·m-2. Moreover, SEC decreased (1.18-1.05 kWh·kg-1) while CE increased (87.0-93.4%), achieving minimum (1.02 kWh·kg-1) and maximum (99.4%) values, respectively, at 6 L·min-1.
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Electrodialysis with Bipolar Membranes for the Generation of NaOH and HCl Solutions from Brines: An Inter-Laboratory Evaluation of Thin and Ultrathin Non-Woven Cloth-Based Ion-Exchange Membranes. MEMBRANES 2022; 12:1204. [PMID: 36557111 PMCID: PMC9786922 DOI: 10.3390/membranes12121204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/21/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
The SEArcularMINE project aims to recover critical raw materials (CRMs) from brines from saltworks, thus facing a CRM shortage within Europe. To promote a fully circular scheme, the project valorises concentrated brines using electrodialysis with bipolar membranes (EDBM) to generate the required amounts of reactants (i.e., acids and bases). Regarding the performances of new non-woven cloth ion-exchange membranes (Suez): (i) an ultra-thin non-woven polyester cloth and (ii) a thin polypropylene cloth acting as the support structures were assessed. Additionally, the anion layer includes a catalyst to promote the water dissociation reaction. The effect of current density (100, 200, and 300 A m-2) on the performance of two combinations of membranes in an inter-laboratory exercise using 2 M NaCl was evaluated. According to statistical analysis ANOVA, there was an agreement on the results obtained in both laboratories. NaOH/HCl solutions up to 0.8 M were generated working at 300 A m-2 using both combinations of membranes. Regarding the performance parameters, stack set-ups incorporating thin polypropylene membranes showed lower specific energy consumption (SEC) and higher specific productivity (SP) than ultra-thin polypropylene ones. Hence, for ultra-thin polypropylene membranes, SEC was reported to be between 2.18 and 1.69 kWh kg-1NaOH and SP between 974 and 314 kg m-2 y-1.
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Feasibility of Producing Electricity, Hydrogen, and Chlorine via Reverse Electrodialysis. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:16062-16072. [PMID: 36255406 PMCID: PMC9671052 DOI: 10.1021/acs.est.2c03407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 10/01/2022] [Accepted: 10/03/2022] [Indexed: 06/16/2023]
Abstract
Reverse electrodialysis (RED) is a technology to generate electricity from two streams with different salinities. While RED systems have been conventionally used for electricity generation, recent works explored combining RED for production of valuable gases. This work investigates the feasibility of producing hydrogen and chlorine in addition to electricity in an RED stack and identifies potential levers for improvement. A simplified one-dimensional model is adopted to assess the technical and economic feasibility of the process. We notice a strong disparity in typical current densities of RED fed with seawater and river water and that in typical water (or chlor-alkali) electrolysis. This can be partly mitigated by using brine and seawater as RED feeds. Considering such an RED system, we estimate a hydrogen production of 1.37 mol/(m2 h) and an electrical power density of 1.19 W/m2. Although this exceeds previously reported hydrogen production rates in combination with RED, the levelized costs of products are 1-2 orders of magnitude higher than the current market prices at the current state. The levelized costs of products are very sensitive to the membrane price and performance. Hence, going forward, manufacturing thinner and highly selective membranes is required to make the system competitive against the consolidated technologies.
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Mining minerals and critical raw materials from bittern: Understanding metal ions fate in saltwork ponds. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 847:157544. [PMID: 35878854 DOI: 10.1016/j.scitotenv.2022.157544] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 07/05/2022] [Accepted: 07/17/2022] [Indexed: 06/15/2023]
Abstract
Seawater represents a potential resource for raw materials extraction. Although NaCl is the most representative mineral extracted other valuable compounds such as Mg, Li, Sr, Rb and B and elements at trace level (Cs, Co, In, Sc, Ga and Ge) are also contained in this "liquid mine". Most of them are considered as Critical Raw Materials by the European Union. Solar saltworks, providing concentration factors of up-to 20 to 40, offer a perfect platform for the development of minerals and metal recovery schemes taking benefit of the concentration and purification achieved along the evaporation saltwork ponds. However, the geochemistry of these elements in this environment has not been yet thoroughly evaluated. Their knowledge could enable the deployment of technologies capable to achieve the recovery of valuable minerals. The high ionic strengths expected (0.5-7 mol/kg) and the chemical complexity of the solutions imply that only numerical geochemical codes, as PHREEQC, and the use of Pitzer model to estimate the activity coefficients of the different species in solution can be adopted to provide valuable description of the systems. In the present work, for the first time, PHREEQC Pitzer code database was extended to include the target minor and trace elements using Trapani saltworks (Sicily, Italy) as a case study system. The model was able to predict: i) the purity in halite and the major impurities contained, mainly Ca, Mg and sulphate species; ii) the fate of minor components as B, Sr, Cs, Co, Ge and Ga along the evaporation ponds. The results obtained pose a fundamental step in critical raw materials mining from seawater brine, for process intensification and combination with desalination.
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Influence of Operational Strategies for the Recovery of Magnesium Hydroxide from Brines at a Pilot Scale. Ind Eng Chem Res 2022; 61:15355-15368. [PMID: 36281439 PMCID: PMC9585888 DOI: 10.1021/acs.iecr.2c02935] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/18/2022] [Accepted: 09/20/2022] [Indexed: 11/06/2022]
Abstract
![]()
The continuous depletion of minerals caused by land mining
and
the increase in their demand
have pushed the development of novel sustainable technological processes
for mineral recovery from unconventional sources. In this context,
magnesium (Mg) has gained considerable attention for its peculiar
properties and high relevance of its compounds, such as magnesium
hydroxide, Mg(OH)2. In the present work, the influence
of several operating conditions on the Mg(OH)2 precipitation
process was thoroughly investigated by adopting a novel multiple feed-plug
flow reactor. The influence of (i) initial Mg2+ concentrations
in the feed stream; (ii) brine and alkaline flow rates; and (iii)
the product recycling strategy (seeded crystallization) was considered.
The results marked the possibility of improving sedimentation and
filterability properties of Mg(OH)2 suspensions by adopting
the recycling strategy to overcome industrial issues associated with
the production of Mg(OH)2 suspensions using NaOH solutions.
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10
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Economic Benefits of Waste Pickling Solution Valorization. MEMBRANES 2022; 12:membranes12020114. [PMID: 35207036 PMCID: PMC8879454 DOI: 10.3390/membranes12020114] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 11/28/2022]
Abstract
An integrated hybrid membrane process, composed of a diffusion dialysis (DD), a membrane distillation (MD) and a reactive precipitation unit (CSTR), is proposed as a promising solution for the valorization and onsite recycling of pickling waste streams. An economic analysis was performed aiming to demonstrate the feasibility of the developed process with a NPV of about EUR 40,000 and a DPBP of 4 years. The investment and operating costs, as well as the avoided costs and the benefits for the company operating the plant, were analyzed with an extensive cost tracking exercise and through face-to-face contact with manufacturers and sector leaders. A mathematical model was implemented using the gPROMS modelling platform. It is able to simulate steady state operations and run optimization analysis of the process performance. The impact of key operating and design parameters, such as the set-point bath concentration and the DD and MD membrane areas, respectively, was investigated and the optimal arrangement was identified. Finally, operating variables and design parameters were optimized simultaneously in a nonlinear framework as a tradeoff between profitability and environmental impact. We show how the integration of new technologies into the traditional pickling industry could provide a significant benefit for the issues of process sustainability, which are currently pressing.
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12
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Diffusion dialysis for the treatment of H2SO4-CuSO4 solutions from electroplating plants: Ions membrane transport characterization and modelling. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2020.118215] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Bipolar membrane reverse electrodialysis for the sustainable recovery of energy from pH gradients of industrial wastewater: Performance prediction by a validated process model. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 287:112319. [PMID: 33721763 DOI: 10.1016/j.jenvman.2021.112319] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 01/16/2021] [Accepted: 03/01/2021] [Indexed: 06/12/2023]
Abstract
The theoretical energy density extractable from acidic and alkaline solutions is higher than 20 kWh m-3 of single solution when mixing 1 M concentrated streams. Therefore, acidic and alkaline industrial wastewater have a huge potential for the recovery of energy. To this purpose, bipolar membrane reverse electrodialysis (BMRED) is an interesting, yet poorly studied technology for the conversion of the mixing entropy of solutions at different pH into electricity. Although it shows promising performance, only few works have been presented in the literature so far, and no comprehensive models have been developed yet. This work presents a mathematical multi-scale model based on a semi-empirical approach. The model was validated against experimental data and was applied over a variety of operating conditions, showing that it may represent an effective tool for the prediction of the BMRED performance. A sensitivity analysis was performed in two different scenarios, i.e. (i) a reference case and (ii) an improved case with high-performance membrane properties. A Net Power Density of ~15 W m-2 was predicted in the reference scenario with 1 M HCl and NaOH solutions, but it increased significantly by simulating high-performance membranes. A simulated scheme for an industrial application yielded an energy density of ~50 kWh m-3 (of acid solution) with an energy efficiency of ~80-90% in the improved scenario.
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Electrodialysis Applications in Wastewater Treatment for Environmental Protection and Resources Recovery: A Systematic Review on Progress and Perspectives. MEMBRANES 2020; 10:E146. [PMID: 32660014 PMCID: PMC7408617 DOI: 10.3390/membranes10070146] [Citation(s) in RCA: 97] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/02/2020] [Accepted: 07/04/2020] [Indexed: 12/19/2022]
Abstract
This paper presents a comprehensive review of studies on electrodialysis (ED) applications in wastewater treatment, outlining the current status and the future prospect. ED is a membrane process of separation under the action of an electric field, where ions are selectively transported across ion-exchange membranes. ED of both conventional or unconventional fashion has been tested to treat several waste or spent aqueous solutions, including effluents from various industrial processes, municipal wastewater or salt water treatment plants, and animal farms. Properties such as selectivity, high separation efficiency, and chemical-free treatment make ED methods adequate for desalination and other treatments with significant environmental benefits. ED technologies can be used in operations of concentration, dilution, desalination, regeneration, and valorisation to reclaim wastewater and recover water and/or other products, e.g., heavy metal ions, salts, acids/bases, nutrients, and organics, or electrical energy. Intense research activity has been directed towards developing enhanced or novel systems, showing that zero or minimal liquid discharge approaches can be techno-economically affordable and competitive. Despite few real plants having been installed, recent developments are opening new routes for the large-scale use of ED techniques in a plethora of treatment processes for wastewater.
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15
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On the Reduction of Power Consumption in Vortexing Unbaffled Bioslurry Reactors. Ind Eng Chem Res 2020. [DOI: 10.1021/acs.iecr.0c00726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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16
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Effect of ion exchange capacity and water uptake on hydroxide transport in PSU-TMA membranes: A DFT and molecular dynamics study. J Memb Sci 2020. [DOI: 10.1016/j.memsci.2020.117837] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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18
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Experimental investigation and modeling of diffusion dialysis for HCl recovery from waste pickling solution. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 235:202-212. [PMID: 30682673 DOI: 10.1016/j.jenvman.2019.01.028] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/07/2019] [Accepted: 01/09/2019] [Indexed: 05/10/2023]
Abstract
Hydrochloric acid recovery from pickling solutions was studied by employing a batch diffusion dialysis (DD) laboratory test-rig equipped with Fumasep membranes. The effect of main operating parameters such as HCl concentration (0.1-3 M) and the presence of Fe2+ (up to 150 g/l) was investigated to simulate the system operation with real industrial streams. The variation of HCl, Fe2+ and water flux was identified. When only HCl is present, a recovery efficiency of 100% was reached. In the presence of FeCl2, higher acid recovery efficiencies, up to 150%, were observed due to the so-called "salt effect", which promotes the passage of acid even against its concentration gradient. A 7% leakage of FeCl2 was detected in the most severe conditions. An original analysis on water flux in DD operation has indicated that osmotic flux prevails at low HCl concentrations, while a dominant "drag flux" in the opposite direction is observed for higher HCl concentrations. A comprehensive mathematical model was developed and validated with experimental data. The model has a time and space distributed-parameters structure allowing to effectively simulate steady-state and transient batch operations, thus providing an operative tool for the design and optimisation of DD units.
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19
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Direct numerical simulations of creeping to early turbulent flow in unbaffled and baffled stirred tanks. Chem Eng Sci 2018. [DOI: 10.1016/j.ces.2018.07.023] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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20
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Long-run operation of a reverse electrodialysis system fed with wastewaters. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2018; 217:871-887. [PMID: 29660712 DOI: 10.1016/j.jenvman.2018.03.110] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Revised: 03/13/2018] [Accepted: 03/25/2018] [Indexed: 06/08/2023]
Abstract
The performance of a Reverse ElectroDialysis (RED) system fed by unconventional wastewater solutions for long operational periods is analysed for the first time. The experimental campaign was divided in a series of five independent long-runs which combined real wastewater solutions with artificial solutions for at least 10 days. The time evolution of electrical variables, gross power output and net power output, considering also pumping losses, was monitored: power density values obtained during the long-runs are comparable to those found in literature with artificial feed solutions of similar salinity. The increase in pressure drops and the development of membrane fouling were the main detrimental factors of system performance. Pressure drops increase was related to the physical obstruction of the feed channels defined by the spacers, while membrane fouling was related to the adsorption of foulants over the membrane surfaces. In order to manage channels partial clogging and fouling, different kinds of easily implemented in situ backwashings (i.e. neutral, acid, alkaline) were adopted, without the need for an abrupt interruption of the RED unit operation. The application of periodic ElectroDialysis (ED) pulses is also tested as fouling prevention strategy. The results collected suggest that RED can be used to produce electric power by unworthy wastewaters, but additional studies are still needed to characterize better membrane fouling and further improve system performance with these solutions.
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21
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Effect of different aqueous solutions of pure salts and salt mixtures in reverse electrodialysis systems for closed-loop applications. J Memb Sci 2018. [DOI: 10.1016/j.memsci.2018.01.036] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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22
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Reverse electrodialysis performed at pilot plant scale: Evaluation of redox processes and simultaneous generation of electric energy and treatment of wastewater. WATER RESEARCH 2017; 125:123-131. [PMID: 28843152 DOI: 10.1016/j.watres.2017.08.008] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 07/24/2017] [Accepted: 08/03/2017] [Indexed: 06/07/2023]
Abstract
This paper describes the experimental campaign carried out with a reverse electrodialysis (RED) demonstration plant (Marsala, Italy) with the main aims of: (i) evaluating the effect of various operating parameters, including the redox processes, on the system performances; (ii) using the plant for the simultaneous generation of electric energy and treatment of wastewater. The prototype (44 × 44 cm2, 500 cell pairs) was tested using both real (brackish water and brine) and artificial solutions. Tests with two different electrode rinse solutions (with or without iron redox couples) were performed. In agreement with the data obtained in the laboratory, the presence of iron ions contributes positively to the power production. The effect of flow rates in the electrode and saline compartments, as well as aging of the electrode rinse solution was also investigated. The possibility to remove an organic pollutant (the azoic dye Acid Orange 7) from the electrode solution was tested, obtaining a very fast and total removal of the pollutant. This experimental campaign represents the first demonstration in a real environment of the abilities of a RED plant to treat wastewater, thus giving useful indications for the spreading of RED technology in the near future.
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23
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On the assessment of power consumption and critical impeller speed in vortexing unbaffled stirred tanks. Chem Eng Res Des 2017. [DOI: 10.1016/j.cherd.2017.04.035] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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24
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Unsteadiness and transition to turbulence in woven spacer filled channels for Membrane Distillation. ACTA ACUST UNITED AC 2017. [DOI: 10.1088/1742-6596/796/1/012003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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25
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Towards 1 kW power production in a reverse electrodialysis pilot plant with saline waters and concentrated brines. J Memb Sci 2017. [DOI: 10.1016/j.memsci.2016.09.015] [Citation(s) in RCA: 88] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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26
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27
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Performance of the first reverse electrodialysis pilot plant for power production from saline waters and concentrated brines. J Memb Sci 2016. [DOI: 10.1016/j.memsci.2015.10.057] [Citation(s) in RCA: 160] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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28
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Flow and mass transfer in spacer-filled channels for reverse electrodialysis: a CFD parametrical study. J Memb Sci 2016. [DOI: 10.1016/j.memsci.2015.09.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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29
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Reverse electrodialysis with saline waters and concentrated brines: A laboratory investigation towards technology scale-up. J Memb Sci 2015. [DOI: 10.1016/j.memsci.2015.05.020] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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30
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A simulation tool for analysis and design of reverse electrodialysis using concentrated brines. Chem Eng Res Des 2015. [DOI: 10.1016/j.cherd.2014.05.009] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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31
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CFD prediction of concentration polarization phenomena in spacer-filled channels for reverse electrodialysis. J Memb Sci 2014. [DOI: 10.1016/j.memsci.2014.05.058] [Citation(s) in RCA: 108] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Solid–Liquid Suspensions in Top-Covered Unbaffled Vessels: Influence of Particle Size, Liquid Viscosity, Impeller Size, and Clearance. Ind Eng Chem Res 2014. [DOI: 10.1021/ie500203r] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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A Thermochromic Liquid Crystals Image Analysis technique to investigate temperature polarization in spacer-filled channels for Membrane Distillation. J Memb Sci 2013. [DOI: 10.1016/j.memsci.2013.06.043] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Power Consumption in Uncovered Unbaffled Stirred Tanks: Influence of the Viscosity and Flow Regime. Ind Eng Chem Res 2013. [DOI: 10.1021/ie402466w] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Modelling and Simulation of Gas–liquid Hydrodynamics in a Rectangular Air-lift Reactor. INTERNATIONAL JOURNAL OF CHEMICAL REACTOR ENGINEERING 2013. [DOI: 10.1515/ijcre-2012-0040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Computational Fluid Dynamics is a quite well established tool for carrying out realistic simulations of process apparatuses. However, as a difference from single phase systems, for multiphase systems the development of CFD models is still in progress. Among the two-phase systems, gas–liquid systems are characterised by an additional complexity level, related to the fact that bubble sizes are not known in advance, being rather the result of formation and breakage-coalescence dynamics and therefore of complex phenomena related to flow dynamics and interfacial effects. In the present work, Euler–Euler Reynolds-averaged flow simulations of an air-lift reactor are reported. All bubbles are assumed to share the same size, and a simplified approach is adopted for modelling inter-phase momentum exchange, that involves bubble terminal velocity as the sole parameter needed. Good agreement between simulation results and literature experimental data is found for all the gas flow rates simulated. This result implies that, despite the many simplifications that have to be adopted in order to make them viable, fully predictive CFD simulations of gas–liquid systems can give rise to reasonably accurate predictions of reactor fluid dynamics.
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Large-eddy simulation of turbulent flow in an unbaffled stirred tank driven by a Rushton turbine. Chem Eng Sci 2005. [DOI: 10.1016/j.ces.2004.11.017] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Assessment of Particle Suspension Conditions in Stirred Vessels by Means of Pressure Gauge Technique. Chem Eng Res Des 2002. [DOI: 10.1205/026387602321143444] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Experiments and CFD Predictions of Solid Particle Distribution in a Vessel Agitated with Four Pitched Blade Turbines. Chem Eng Res Des 2001. [DOI: 10.1205/02638760152721253] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Numerical prediction of flow fields in baffled stirred vessels: A comparison of alternative modelling approaches. Chem Eng Sci 1998. [DOI: 10.1016/s0009-2509(98)00149-3] [Citation(s) in RCA: 221] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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