The chlor-alkali process: A review of history and pollution

Crook, Jedidiah; Mousavi, Aliyar

doi:10.1080/15275922.2016.1177755

Cited by 118 publications

(77 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here, we define a diaphragm as an inert, nonconducting porous layer that is imbibed with electrolyte, that possesses low hydraulic permeability, and adjacent to which solution flows. Since the 1920s such diaphragms have been used in brine electrolysis (i.e., chlor-alkali processing) to produce chlorine gas and caustic soda simultaneously [42]. Early diaphragms were comprised of paper, and later asbestos, to reduce caustic-soda transport between electrodes [43].…”

Section: Introductionmentioning

confidence: 99%

Quantifying the trade-offs between energy consumption and salt removal rate in membrane-free cation intercalation desalination

Liu

Smith

2018

Electrochimica Acta

View full text Add to dashboard Cite

Electrochemical desalination devices that use redox-active cation intercalation electrodes show promise for desalination of salt-rich water resources with high water recovery and low energy consumption. While previous modeling and experiments used ion-exchange membranes to maximize charge efciency, here a membrane-free alternative is evaluated to reduce capital cost by using a porous diaphragm to separate Na 1+x NiFe(CN) 6 electrodes. Two-dimensional porous-electrode modeling shows that, while charge efficiency losses are inherent to a diaphragm-based architecture, charge efficiency values approaching the anion transference number (61% for NaCl) are achievable for diaphragms with sufficiently low salt conductance. Closed-form equations are thereby derived that relate charge efficiency to the non-dimensional Pèclet and Damköhler numbers that enable the selection of current and flow velocity to produce a desired degree-of-desalination. Simulations using these conditions are used to quantify the tradeoffs between energy consumption and salt removal rate for diaphragmbased cells operated at a range of currents. The simulated distributions of reactions are shown to result from the local salt concentration variations within electrodes using diffusion-potential theory. We also simulate the cycling dynamics of various flow configurations and show that flow-through electrodes exceed the degree-of-desalination compared with flow-by and flow-behind configurations due to solution stagnation within electrodes.

show abstract

Section: Introductionmentioning

confidence: 99%

Quantifying the trade-offs between energy consumption and salt removal rate in membrane-free cation intercalation desalination

Liu

Smith

2018

Electrochimica Acta

View full text Add to dashboard Cite

show abstract

“…Industrial processes, such as the chlor-alkali electrolysis, [1][2][3][4][5] demand large quantities of energy. Between 2,200-2,600 kWh are consumed per ton of chlorine in a conventional membrane NaCl electrolysis process.…”

Section: Introductionmentioning

confidence: 99%

“…[20] Since the oxygen reduction reaction (ORR) has a higher standard electrode potential compared to the hydrogen evolution reaction (HER) [Eqs. (1) and (2)] the overall cell potential can be lowered to approx. 2 V resulting in savings of up to 1 V.…”

Section: Introductionmentioning

confidence: 99%

Improvement of Oxygen‐Depolarized Cathodes in Highly Alkaline Media by Electrospinning of Poly(vinylidene fluoride) Barrier Layers

et al. 2020

View full text Add to dashboard Cite

Oxygen‐depolarized cathodes (ODC) were developed for chlor‐alkali electrolysis to replace the hydrogen evolution reaction (HER) by the oxygen reduction reaction (ORR) providing electrical energy savings up to 30 % under industrially relevant conditions. These electrodes consist of micro sized silver grains and polytetrafluoroethylene, forming a homogeneous electrode structure. In this work, we report on the modification of ODCs by implementing an electrospun layer of hydrophobic poly(vinylidene fluoride) (PVDF) into the ODC structure, leading to a significantly enhanced ORR performance. The modified electrodes are physically characterized by liquid flow porometry, contact angle measurements and scanning electron microscopy. Electrochemical characterization is performed by linear sweep voltammetry and chronopotentiometry. The overpotential for ORR at application near conditions could be reduced by up to 75 mV at 4 kA m−2 and 135 mV at a higher current density of 9.5 kA m−2. Consequently, we propose that modifying ODCs by electrospinning is an effective and cost‐efficient way to further reduce the energy demand of the ORR in highly alkaline media.

show abstract

“…20 However, three decades passed before Faraday made use of this current to electrolyze acetic acid, 21 thereby paving the way for subsequent scientific breakthroughs such as the Kolbe electrolysis, 22 the Hall-Héroult process 23 and the chloralkali process. 24 Electrochemical reactions typically require two electrodes, an anode and a cathode. By immersing them into a solution containing the substrate and eventually additives to ensure a sufficient conductivity of the solution, the setup for an ordinary electrochemical cell is complete.…”

Section: Introductionmentioning

confidence: 99%

Anodic Oxidation as an Enabling Tool for the Synthesis of Natural Products

Geske

Sato²,

Opatz³

2020

Synthesis

View full text Add to dashboard Cite

Electrochemistry provides a valuable toolbox for organic synthesis and offers an appealing, environmentally benign alternative to the use of stoichiometric quantities of chemical oxidants or reductants. Its potential to control current efficiency along with providing alternative reaction conditions in a classical sense makes electrochemistry a suitable method for large-scale industrial transformations as well as for laboratory applications in the synthesis of complex molecular architectures. Even though research in this field has intensified over the recent decades, many synthetic chemists still hesitate to add electroorganic reactions to their standard repertoire, and hence, the full potential of preparative organic electrochemistry has not yet been unleashed. This short review highlights the versatility of anodic transformations by summarizing their application in natural product synthesis.1 Introduction2 Shono-Type Oxidation3 C–N/N–N Bond Formation4 Aryl–Alkene/Aryl–Aryl Coupling5 Cycloadditions Triggered by Oxidation of Electron-Rich Arenes6 Spirocycles7 Miscellaneous Transformations8 Future Prospects

show abstract

The chlor-alkali process: A review of history and pollution

Cited by 118 publications

References 5 publications

Quantifying the trade-offs between energy consumption and salt removal rate in membrane-free cation intercalation desalination

Quantifying the trade-offs between energy consumption and salt removal rate in membrane-free cation intercalation desalination

Improvement of Oxygen‐Depolarized Cathodes in Highly Alkaline Media by Electrospinning of Poly(vinylidene fluoride) Barrier Layers

Anodic Oxidation as an Enabling Tool for the Synthesis of Natural Products

Contact Info

Product

Resources

About