Improved fluid mixing and power density in reverse electrodialysis stacks with chevron-profiled membranes

Pawlowski, Sylwin; Rijnaarts, Timon; Saakes, Michel; Nijmeijer, DC Kitty; Crespo, João G.; Велизаров, Светлозар

doi:10.1016/j.memsci.2017.03.003

Cited by 68 publications

(48 citation statements)

References 42 publications

(99 reference statements)

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“…The maximum power densities recorded in this study (given in Appendix D) are low compared to those reported in literature [25,44,45] but in line with a complementary study performed by Kingsbury et al (2018) [15]. Although it was reported that a minimum net power density of 2.2 W/m² is needed to make RED commercially attractive as a source of renewable energy [46], the focus in this investigation was on comparing pre-treatment techniques and developing a system for seawater desalination.…”

Section: Pressure Drop and Power Densitycontrasting

confidence: 77%

See 1 more Smart Citation

Secondary treated domestic wastewater in reverse electrodialysis: What is the best pre-treatment?

Vanoppen

Vooren

Gutierrez

et al. 2019

Separation and Purification Technology

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art Highlights  RED-RO is a promising technology for energy-efficient seawater desalination  Secondary-treated wastewater is a potential low salinity source for RED  An efficient pre-treatment of wastewater is needed before use in RED  Rapid sand filtration and 100 µm provide efficient wastewater pre-treatment  River bank filtration does not provide adequate feed water quality AbstractAlthough Reverse Electrodialysis (RED) is most commonly known as a selective separation technology used for the production of sustainable energy, it can also serve as a valuable pre-desalination tool. By coupling RED to Reverse Osmosis (RO) for seawater desalination: (1) sustainable energy is produced in the RED process and (2) seawater is partially desalinated prior to RO thus, decreasing the energy demand. In this study, secondary-treated wastewater is proposed as the low salinity source in RED and suitable pre-treatment techniques for this effluent are investigated. Although it is generally accepted that RED is less prone to fouling than typical pressure driven membrane processes, results showed that pre-treatment is a key to ensure efficient operation of the wastewater-seawater RED. Both 100 µm filtration and rapid sand filtration proved to be suitable, with an increase in pressure drop of only 0.09-0.18 bar and a permselectivity decrease of only approximately 20% during 40 days of continuous operation. Conversely, River bank filtration did not perform better than the non-pretreated sample. As such, 100 µm filtration and rapid sand filtration are considered suitable, robust, and cost efficient pretreatment options for wastewater fed RED, enabling the improvement of the hybrid process of RED-RO seawater desalination.

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Section: Pressure Drop and Power Densitycontrasting

confidence: 77%

“…3.3.1. Chemical analysis to improve power density are currently being investigated, including membrane profiling [24,25,44], conductive spacers [22] and alternative modes of operation [23,45].…”

Section: Membrane Autopsymentioning

confidence: 99%

Secondary treated domestic wastewater in reverse electrodialysis: What is the best pre-treatment?

Vanoppen

Vooren

Gutierrez

et al. 2019

Separation and Purification Technology

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“…Nevertheless, experiments, models, and simulations concerning fluid-structure interactions and its effects are still few, especially for electro-membrane processes such as ED and RED. Recently, several research groups have addressed self-distancing profiled membranes, which are a promising alternative to conventional flat membranes supported by net spacers [14][15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Pressure-Induced Deformation of Pillar-Type Profiled Membranes and Its Effects on Flow and Mass Transfer

et al. 2019

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In electro-membrane processes, a pressure difference may arise between solutions flowing in alternate channels. This transmembrane pressure (TMP) causes a deformation of the membranes and of the fluid compartments. This, in turn, affects pressure losses and mass transfer rates with respect to undeformed conditions and may result in uneven flow rate and mass flux distributions. These phenomena were analyzed here for round pillar-type profiled membranes by integrated mechanical and fluid dynamics simulations. The analysis involved three steps: (1) A conservatively large value of TMP was imposed, and mechanical simulations were performed to identify the geometry with the minimum pillar density still able to withstand this TMP without collapsing (i.e., without exhibiting contacts between opposite membranes); (2) the geometry thus identified was subject to expansion and compression conditions in a TMP interval including the values expected in practical applications, and for each TMP, the corresponding deformed configuration was predicted; and (3) for each computed deformed configuration, flow and mass transfer were predicted by computational fluid dynamics. Membrane deformation was found to have important effects; friction and mass transfer coefficients generally increased in compressed channels and decreased in expanded channels, while a more complex behavior was obtained for mass transfer coefficients.

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“…Electrical conductivity is one of the most important characteristics of ion-exchange membranes [31][32][33][34] but also measuring of electrical properties make it is possible to estimate the thickness of active layer in reverse osmosis or nanofiltration membranes [20][21][22]35], porosity of 4 porous sublayers [25,26,36], monitoring of deposition (fouling) on top of the membrane [25,26,36], to get insight in the transport behavior of different charged species within the membrane [21,23] or evaluate the wetting of microporous hydrophobic membranes used in membrane contactors [27]. It should be noticed that electrical impedance spectroscopy is widely used for characterization of resistance and capacitance of active and porous sub-layers of reverse osmosis membranes [20], nanofiltration membranes [20][21][22]35], evaluation of (bio)fouling [25,26,36], water presence and ionic liquid loss in supported liquid membranes [37], monitoring of membrane modification with the charged species [38], wetting of porous membranes used in membrane contactors [27] and study of piezoelectric properties of porous membranes [39].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of liquid transport properties of hydrophobic polymers of intrinsic microporosity by electrical resistance measurement

Yushkin

Vasilevsky

Khotimskiy

et al. 2018

Journal of Membrane Science

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In this work, the electrical resistance method was used to get an insight of the liquid transport through the polymers with excess of fractional free volume. The dense films based on the first generation of polymers of intrinsic microporosity, disubstituted polyacetylenes PMP and PTMSP, were used; water-ethanol binary mixtures allowed to adjust the affinity of the liquid phase to selected polymers continuously. In this work, the liquid-membrane interaction was considered as a stepwise occupation of accessible free volume elements within the polymer, while the appearance of continuous (pseudo)liquid channels in the polymeric matrix, so-called percolation clusters, was required for formation of hydrodynamic liquid transport. Since the appearance of such percolation clusters might dramatically change the conductivity of hydrophobic materials, it was proposed to use the electrical resistance method to investigate the evaluation of selected polymers from being a barrier (water) to being permeable (ethanol) with respect to the liquid composition. To highlight the electrical resistance of the swollen films, all water/ethanol solutions contained NaCl (0.5g/L). The steady-state values of liquid permeation, sorption/swelling, and electrical conductivity data were considered together and discussed. The electric resistance was significantly varied for 30 µm dense films of PMP (1-1300 kΩ) and PTMSP (0.15-910 kΩ) by the adjustment of ethanol content in water. The phase shift (25-100000 Hz) illustrated that the behavior of PTMSP and PMP membranes changed from mainly capacitive at low ethanol concentrations to the ion conductive as higher ethanol content. The very good quantitative agreement was found between the relative change of the membrane electrical resistance and the permeability as a function of the ethanol content in the liquid phase. Consequently, electrical resistance measurements could be used as an express method to determine the membrane permeability of low permeable materials, since the time required to get 2 steady-state results was found to be much shorter for electrical resistance measurements than for permeability measurements.

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Improved fluid mixing and power density in reverse electrodialysis stacks with chevron-profiled membranes

Cited by 68 publications

References 42 publications

Secondary treated domestic wastewater in reverse electrodialysis: What is the best pre-treatment?

Secondary treated domestic wastewater in reverse electrodialysis: What is the best pre-treatment?

Pressure-Induced Deformation of Pillar-Type Profiled Membranes and Its Effects on Flow and Mass Transfer

Evaluation of liquid transport properties of hydrophobic polymers of intrinsic microporosity by electrical resistance measurement

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