A direct comparison of flow-by and flow-through capacitive deionization

Remillard, E. Marielle; Shocron, Amit N.; Rahill, John; Suss, Matthew E.; Vecitis, Chad D.

doi:10.1016/j.desal.2018.01.018

Cited by 70 publications

(36 citation statements)

References 35 publications

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“…Laser perforation within the ft-electrode macrostructure have been shown to enhance the permeability due to an increase in macroporosity (E. Guyes et al., 2017). Ft-CDI, however could have higher faradaic reactions leading to anode oxidation (Remillard et al., 2018), and flowing through the electrode could incur elevated pumping energy requirements due to head loss in the electrodes.…”

Section: Introductionmentioning

confidence: 99%

Reducing impedance to ionic flux in capacitive deionization with Bi-tortuous activated carbon electrodes coated with asymmetrically charged polyelectrolytes

et al. 2019

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Capacitive deionization (CDI) with electric double layers is an electrochemical desalination technology in which porous carbon electrodes are polarized to reversibly store ions. Planar composite CDI electrodes exhibit poor energetic performance due the resistance associated with salt depletion and tortuous diffusion in the macroporous structure. In this work, we investigate the impact of bi-tortuosity on desalination performance by etching macroporous patterns along the length of activated carbon porous electrodes in a flow-by CDI architecture. Capacitive electrodes were also coated with thin asymmetrically charged polyelectrolytes to improve ion-selectivity while maintaining the bitortuous macroporous channels. Under constant current operation, the equivalent circuit resistance in CDI cells operating with bi-tortuous electrodes was approximately 2.2 times less than a control cell with unpatterned electrodes, leading to significant increases in working capacitance (20–22 to 26.7–27.8 F g −1 ), round-trip efficiency (52–71 to 71–80%), and charge efficiency (33–59 to 35–67%). Improvements in these key performance indicators also translated to enhanced salt adsorption capacity, rate, and most importantly, the thermodynamic efficiency of salt separation (1.0–2.0 to 2.2–4.1%). These findings demonstrate that the use of bi-tortuous electrodes is a novel approach of reducing impedance to ionic flux in CDI.

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Section: Introductionmentioning

confidence: 99%

Reducing impedance to ionic flux in capacitive deionization with Bi-tortuous activated carbon electrodes coated with asymmetrically charged polyelectrolytes

et al. 2019

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“…Several aspects have an impact on the performance of the capacitive desalination system in the process of absorbing salt ions (Hawks et al, 2018). The movement of salt ions towards the surface of the electrode determines the number of salt ions absorbed into the surface of the carbon plate (Remillard et al, 2018). The faster the rate of electrolyte solution applied to the desalination system, the salt ions will tend to be pushed by the flow current than those affected by the electric fields on the two carbon plates (Remillard et al, 2018).…”

Section: Flow Velocity Variationsmentioning

confidence: 99%

“…The movement of salt ions towards the surface of the electrode determines the number of salt ions absorbed into the surface of the carbon plate (Remillard et al, 2018). The faster the rate of electrolyte solution applied to the desalination system, the salt ions will tend to be pushed by the flow current than those affected by the electric fields on the two carbon plates (Remillard et al, 2018). Conversely, the slower flow rate of the electrolyte solution is also less effective for the performance of the desalination system because it will produce freshwater products with low volume and long operational duration (Mutha et al, 2018)(Carmona-Orbezo & Dryfe, 2021.…”

Section: Flow Velocity Variationsmentioning

confidence: 99%

THE INFLUENCE OF NaCl SOLUTION FLOW RATE ON ION ABSORPTION OF CAPACITIVE ELECTRIC CARBON PLATE

Pramartaningthyas¹

2021

J. pena sains

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Research on desalination technology in seawater is being developed. This is because sea water has not been used optimally to meet community needs. One of the rapidly developing desalination systems is desalination technology using a capacitive carbon plate. The development of this desalination system technology is carried out using electrode plates made of carbon. These plates are capable of absorbing salt ions through the porous surface. The amount of ion absorbed is determined by the pore surface structure of the plate, the salt flow rate, the number of plates used, the applied voltage and other factors. The salt flow rate between the carbon plates determines the speed of the salt ions to reach the smallest pores on each plate surface. For this reason, this article has conducted research by testing the variation in the flow rate of NaCl solution to the amount of salt ions absorbed on the carbon plate.

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“…desorption, leading to non-continuous operation [15], [51]. Additionally, the regeneration step can cause cross-contamination between the effluent streams, resulting in lower water recovery [52]. This step negatively affects the fundamental motivators for CDI technology:…”

Section: Introductionmentioning

confidence: 99%

“…However, conventional CDI cells invariably experience co-ion expulsion, which reduces their charge efficiency [73]. The necessity of a regeneration step in conventional CDI invariably increases energy consumption [51], [52]. For CDI to be considered a green technology, it is necessary to account for the operating energy.…”

Section: Introductionmentioning

confidence: 99%

MXenes as Flow Electrodes for Capacitive Deionization of Wastewater

Mansoor¹

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The energy-water nexus poses an integrated research challenge, while opening up an opportunity space for the development of energy efficient technologies for water remediation. Capacitive Deionization (CDI) is an upcoming reclamation technology that uses a small applied voltage applied across electrodes to electrophoretically remove dissolved ionic impurities from wastewater streams. Similar to a supercapacitor, the ions are stored in the electric double layer of the electrodes. Reversing the polarity of applied voltage enables recovery of the removed ionic impurities, allowing for recycling and reuse. Simultaneous materials recovery and water reclamation makes CDI energy efficient and resource conservative, with potential to scale it up for industrial applications. The efficiency of the technology depends on the architectural design of the CDI cell, control of operating conditions, and the nature of the electrodes used. In this project we report on the performance of Ti3C2Tx MXenes flow electrodes in a CDI cell design. MXenes are a novel class of two-dimensional (2D) transition metal carbides, nitrides and carbonitrides with the general formula Mn+1XnTx where M is an early transition metal, X is carbon and/or nitrogen, Tx represents the surface terminations. Ti3C2Tx MXenes synthesized at Boise State, were employed as a flow electrode solution in an established CDI cell for targeted and selective ion removal. Performance metrics of achieved adsorption capacity, ion removal efficiency, regeneration efficiency, energy consumption, and charge efficiency, exceed those of currently prevalent electrode systems. In addition, rheological properties of the Ti3C2Tx MXenes colloidal solution were evaluated. This work establishes the deionization performance of Ti3C2Tx MXene based flow electrodes while providing further insight towards understanding the effect of structure and surface functionalization on the resultant deionization efficiency.

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A direct comparison of flow-by and flow-through capacitive deionization

Cited by 70 publications

References 35 publications

Reducing impedance to ionic flux in capacitive deionization with Bi-tortuous activated carbon electrodes coated with asymmetrically charged polyelectrolytes

Reducing impedance to ionic flux in capacitive deionization with Bi-tortuous activated carbon electrodes coated with asymmetrically charged polyelectrolytes

THE INFLUENCE OF NaCl SOLUTION FLOW RATE ON ION ABSORPTION OF CAPACITIVE ELECTRIC CARBON PLATE

MXenes as Flow Electrodes for Capacitive Deionization of Wastewater

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