Performance evaluation of optimized carbon xerogel electrode in desalination through flow-electrode capacitive deionization: capacitance optimization by response surface methodology
“…Fig. 10Optimization plots for maximizing the capacitance of final Carbon Xerogel catalyzed by Na 2 CO 3 : a) Capacitance vs pH, b) Capacitance vs R/L and c) Capacitance vs PT [51].…”
Carbon Xerogel is an economic choice of material for electrodes with applications in Electric Double Layer Capacitors (EDLCs) and Capacitive DeIonization systems (CDI, particularly for desalination). The objective here is to optimize Carbon Xerogel's performance, specifically its capacitance, through multi-parameter optimization using Response Surface Methodology (RSM). We choose NaOH as the catalyst and select as the optimization parameters (i) the pH of the initial Resorcinol-Formaldehyde-Catalyst (RFC) solution, (ii) Reactants to Liquid mass ratio (R/L) of the RFC solution, and (iii) the Pyrolysis Temperature (PT). For a selected range of these three parameters, we obtain an optimum capacitance of Carbon Xerogel equal to 37.6 F/g with optimized parameters PT = 800, R/L = 30% and pH = 5.7. Through comparing Carbon Xerogel samples synthesized with Na
2
CO
3
versus NaOH as the catalyst, we show that the capacitance not only depends on the pH of the initial RFC solution, but also is a strong function of the catalyst material.
“…Fig. 10Optimization plots for maximizing the capacitance of final Carbon Xerogel catalyzed by Na 2 CO 3 : a) Capacitance vs pH, b) Capacitance vs R/L and c) Capacitance vs PT [51].…”
Carbon Xerogel is an economic choice of material for electrodes with applications in Electric Double Layer Capacitors (EDLCs) and Capacitive DeIonization systems (CDI, particularly for desalination). The objective here is to optimize Carbon Xerogel's performance, specifically its capacitance, through multi-parameter optimization using Response Surface Methodology (RSM). We choose NaOH as the catalyst and select as the optimization parameters (i) the pH of the initial Resorcinol-Formaldehyde-Catalyst (RFC) solution, (ii) Reactants to Liquid mass ratio (R/L) of the RFC solution, and (iii) the Pyrolysis Temperature (PT). For a selected range of these three parameters, we obtain an optimum capacitance of Carbon Xerogel equal to 37.6 F/g with optimized parameters PT = 800, R/L = 30% and pH = 5.7. Through comparing Carbon Xerogel samples synthesized with Na
2
CO
3
versus NaOH as the catalyst, we show that the capacitance not only depends on the pH of the initial RFC solution, but also is a strong function of the catalyst material.
“…An FCDI normally requires at least one pair of IEMs between the two flow electrodes, with an AEM enabling the selective permeation of anions to the anode chamber and a CEM allowing for the preferential passage of cations to the cathode chamber when an electrical potential difference is applied across the two electrodes, leading to desalination of the feed stream. − Most of the FCDI devices reported in the literature use commercially available IEMs, as summarized in Table . Type I IEMs from Fujifilm and Neosepta IEMs from Tokuyama are more prevalent than other alternatives in view of their lower electric resistance and wider pH stability range, which are crucial factors influencing IEM performance in bench-scale trials.…”
Section: Fcdi Designs and Operational
Modesmentioning
With the increasing
severity of global water scarcity, a myriad
of scientific activities is directed toward advancing brackish water
desalination and wastewater remediation technologies. Flow-electrode
capacitive deionization (FCDI), a newly developed electrochemically
driven ion removal approach combining ion-exchange membranes and flowable
particle electrodes, has been actively explored over the past seven
years, driven by the possibility of energy-efficient, sustainable,
and fully continuous production of high-quality fresh water, as well
as flexible management of the particle electrodes and concentrate
stream. Here, we provide a comprehensive overview of current advances
of this interesting technology with particular attention given to
FCDI principles, designs (including cell architecture and electrode
and separator options), operational modes (including approaches to
management of the flowable electrodes), characterizations and modeling,
and environmental applications (including water desalination, resource
recovery, and contaminant abatement). Furthermore, we introduce the
definitions and performance metrics that should be used so that fair
assessments and comparisons can be made between different systems
and separation conditions. We then highlight the most pressing challenges
(i.e., operation and capital cost, scale-up, and commercialization)
in the full-scale application of this technology. We conclude this
state-of-the-art review by considering the overall outlook of the
technology and discussing areas requiring particular attention in
the future.
“…Activated carbon is often used for this purpose. Some attempts have been also carried out to use other carbon materials such as carbon aerogels [30], [31], carbon black (CB) particles [32], Activated Charcoal [33]- [35], activated charcoal/commercial carbon black [36], [37] and activated carbon (AC)/MnO2 composite [38].…”
Population growth and increasing global demand for freshwater have raised a serious challenge for the depleting sources of freshwater in the 21st century. Desalination technologies can be a reliable technique for providing freshwater. Capacitive deionization is one of the innovative desalination methods that has received increasing interest. Flow-electrode capacitive deionization (FCDI) (a new architecture of capacitive deionization) is one of the efficient, cost-effective, and environmentally-friendly desalination methods for freshwater production. In this experimental research, the performance of an FCDI system was investigated and the influence of important parameters such as flow rate of flow-electrodes, electrolyte salt concentration of flow-electrodes, and initial feed water concentration will be assessed on the efficiency of desalination operation. In this study, the flow-electrodes operated in short-circuited closed-cycle operation (SCC) mode, and also the feed water operated similarly to the flow-electrodes in closed-cycle. Moreover, in all the experiments, the salt adsorption capacity (SAC) and salt removal efficiency (SRE) was calculated. Herein, by optimizing the above mentioned parameters, the salt removal efficiency of 83% and a SAC value of 29.12 mg/g dry carbon were achieved in 5 hours.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
