Three-dimensional electrochemical reactor

Zhang H, Wu X, Zhang Y, Zhang D (2010) Application of response surface methodology to the treatment of landfill leachate in a three dimensional electrochemical reactor. Waste manage 30 2096-2102... 

H. Moffat and K.F. Jensen. Three-Dimensional Flow Effects in Silicon CVD in Horizontal Reactors. J. Electrochem. Soc., 135(2) 459-471,1988. 

Direct reduction of metal ions is undoubtedly the electrochemical reduction process that has reached the highest degree of technical and commercial development. Fortunately, the concentration of these ions in aqueous streams and wastes is typically low, but this introduces an additional complication for their treatment because mass transfer becomes severely limited. To counter this, electrochemists have designed reactors that promote more turbulence and higher contact areas. Three-dimensional and moving electrodes offer promising alternatives. 

In the past, many candidate processes failed to yield the required return on investment because reactor designs at the allowable capital investment were not available. In spite of this, applications for electrosynthesis with the required profitability are growing as electrochemical engineering with a "systems" approach develops. To apply some of the newer chemical proposals it will be necessary to develop even more accurate mathematical design models and more innovative three-dimensional low-voltage-drop electrodes. 

Thus various types of electrochemical reactors with forced flow of depolarizer to the electrode surface, with large surface electrodes minimizing the interelectrode gap, generators with three dimensional electrodes, etc. have been devised. 

There is vast literature detailing the use of different electrochemical reactors used for metal removal [2, 6]. The main types of electrochemical reactors can be classified first according to the kind of electrode as two or three-dimensional. The second classification considers the movement of the electroactive material with relation to a fixed referential. Thus the electrodes can be classified as static or mobile. Figure 1 shows the major electrode classifications according to geometry and fluid dynamics [1]. 

Electrode materials and scalable reactors - in different bioelectrochemical systems expensive electrode materials such as carbon nanotubes or precious metal electrodes are used. These materials are unconsolidated for large-scale MES. In terms of maximizing productivity and minimizing costs, cheap and reusable three-dimensional electrodes are needed. In a technical electrochemical reactor, the use of an expensive separator such as a membrane should be avoided. During the lab stage, the scalability of the reactor concept should receive attention as important parameter. 

Perez OG, Bisang JM (2010) Theoretical and experimental study of electrochemical reactors with three-dimensional bipolar electrodes. J Appl Electrochem 40 709-718... 

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