Seawater Reverse Osmosis Brines as a New Salt Source for the Chlor-Alkali Industry: Integration of NaCl Concentration by Electrodialysis

Casas, S.; Aladjem, C.; Cortina, José Luis; Larrotcha, E.; Cremades, Lázaro V.

doi:10.1080/07366299.2012.686849

Cited by 58 publications

(36 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Researchers have conducted numerous studies related to desalination of brackish water and seawater to produce potable water. Among the proposed desalination methods, such as thermal desalination, crystallization, ion exchange, and solvent extraction, reverse osmosis (RO) is one of the most promising potential types of technology for seawater desalination [2]. However, several drawbacks are associated with RO, including (1) high energy requirement; (2) low recovery rate; and (3) environmental impact caused by brine discharge [3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Exploring an innovative surfactant and phosphate-based draw solution for forward osmosis desalination

Nguyen

Chen

Nguyen

et al. 2015

Journal of Membrane Science

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Exploring an innovative surfactant and phosphate-based draw solution for forward osmosis desalination

Nguyen

Chen

Nguyen

et al. 2015

Journal of Membrane Science

View full text Add to dashboard Cite

“…Nowadays, membrane electrolysis is considered the best available technology for the chlor-alkali industry [1], as it shows the lowest energy consumption [2] and it is considered to be more environmental friendly than diaphragm and amalgam electrolysis. The main drawback of the membrane electrolysis is that it requires highly concentrated brines (300 g/L as NaCl) with only minimal content of bivalent impurities: sum of magnesium and calcium less than 20 mg/L and sulfate concentration less than 7 g/L [3]. The presence of magnesium in the membrane electrolysis feed can lead to the evolution of hydrogen on the anode, which can react with the chlorine [4].…”

Section: Introductionmentioning

confidence: 99%

Electrodialytic concentration of NaCl for the chlor-alkali industry

Mitko

Mikołajczak

Turek

2015

Desalination and Water Treatment

View full text Add to dashboard Cite

A B S T R A C TProduction of chlorine and sodium hydroxide in the membrane electrolysis plants requires saturated brines, free of calcium, magnesium, and sulfates. On the other hand, desalination plants produce waste brines, which are considered as an environmental hazard. Electrodialysis with univalent permselective membranes can simultaneously preconcentrate the sodium chloride solution up to the level required by the chlor-alkali industry and decrease the salinity of the desalination plant brines. In order to assess the bivalent ions transport across univalent permselective membranes during the NaCl concentration process, a series of batch-scale experiments were performed in an electrodialyzer of 4.5 cm 2 effective membrane area and four membrane pairs. The tested membranes were Neosepta CMS/ACS and Aciplex K-192/A-192, the tested concentration range was 0.3-3.0 g/L in case of Ca 2+ , 0.6-6.0 g/L in case of Mg 2+ , 1-20 g/L in case of SO 2À 4 , and 35-300 g/L in case of NaCl. The results allowed the estimation of empirical mass transport coefficients in the membrane. Based on the estimated parameters and a hydrodynamic model of a single-pass electrodialyzer, an electrodialyzer was designed and the energy consumption of saturated brine production was estimated.

show abstract

“…The brine needs to be pure and have a high concentration of NaCl; impurity concentrations must be very low. This often requires costly purification steps prior to electrolysis [4]. For this reason, a promising industrial approach for the chlor-alkali industry is to operate the salt manufacturing with ED using discharged brines from a seawater reverse osmosis (SWRO) desalination plant and using the ED concentrated brine for chlor-alkali application.…”

Section: Introductionmentioning

confidence: 99%

“…Two different doping agents were selected to increase the hydrophobicity of coated PANi: pTSA and valine. In previous work [16] pTSA was selected as doping agent and the results demonstrated that PANi-pTSA has a very high selectivity for monovalent 4 cations. In the present study, valine was the second doping agent selected to increase the hydrophobicity.…”

Section: Introductionmentioning

confidence: 99%

“…Electrodialysis (ED) is a separation process used for concentration of reverse osmosis (RO) desalination brines and as salt valorization option [1][2][3][4], such as sodium chloride concentration for the chlor-alkali industry [5]. The chlor-alkali process is one of the largest electrochemical processes in which chlorine and sodium hydroxide are produced simultaneously by the electrolysis of a sodium chloride solution [6].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis of a monovalent selective cation exchange membrane to concentrate reverse osmosis brines by electrodialysis

et al. 2015

View full text Add to dashboard Cite

In this work, novel monovalent selective cation exchange membranes (CEMs) with different mixtures of polyvinylidene fluoride (PVDF) and sulfonated PVDF (S-PVDF) were synthesized. The selected composite membranes were modified by surface polymerization of polyaniline (PANi) to improve their monovalent cation selectivity. PANi was doped with p-toluene sulfonic acid (pTSA) or L-valine (2-amino-3-methylbutanoic acid) and the selectivity of each CEM was determined. Membrane properties, such as chemical composition, water uptake, ion exchange capacity, permselectivity, contact angle and crystallinity were measured. The influence of the applied voltage was also studied. The newly developed membranes were used for electrodialytic concentration of NaCl from synthetic reverse osmosis (RO) brine. Doped membranes with pTSA ( =0.13, =3.59) and valine ( =0.09, =0.8) have a higher selectivity for sodium than the composite ones ( =0.63, =6.82). Moreover, the increase of applied voltage results in an increase of the selectivity for monovalent ions.

show abstract

Seawater Reverse Osmosis Brines as a New Salt Source for the Chlor-Alkali Industry: Integration of NaCl Concentration by Electrodialysis

Cited by 58 publications

References 24 publications

Exploring an innovative surfactant and phosphate-based draw solution for forward osmosis desalination

Exploring an innovative surfactant and phosphate-based draw solution for forward osmosis desalination

Electrodialytic concentration of NaCl for the chlor-alkali industry

Synthesis of a monovalent selective cation exchange membrane to concentrate reverse osmosis brines by electrodialysis

Contact Info

Product

Resources

About