Electrochemical Micro Reactors

Reactor 29 [R 29] Multi-sectioned Electrochemical Micro Reactor... 

Figure 4.30 Electrochemical micro reactor, a diaphragm micro flow cell, applied to perform the cation flow method. Assembled device (left). Disassembled device showing the two compartments of the cell within the housings and the diaphragm (right) [67. ...

Figure 4.33 Electrochemical micro reactor with integrated electrode cooler. Left overall view. Right schematic of dismantled reactor [69].

Micro reaction systems may help to overcome or at least reduce some of the above-mentioned limitations [69]. Electrochemical micro reactors with miniature flow cells where electrodes approach to micrometer distances should have much improved field homogeneity. As a second result of confined space processing, the addition of a conducting salt may be substantially reduced. In addition, benefits from a uniform flow distribution and efficient heat transfer may be utilized. 

Reactor type Electrochemical micro flow cell Diaphragm material PTFE... 

Beneficial Micro Reactor Properties for Electrochemical C-C Bond Formation with Cations... 

Drivers for Performing the Electrochemical Oxidations of Arylmethanes in Micro Reactors... 

The first study on the oxidation of arylmethanes used this reaction as a model to show the general advantages of electrochemical micro processing and to prove the feasibility of an at this time newly developed reactor concept [69]. Several limits of current electrochemical process technology hindered its widespread use in synthetic chemistry [69]. As one major drawback, electrochemical cells stiU suffer from inhomogeneities of the electric field. In addition, heat is released and large contents of electrolyte are needed that have to be separated from the product. 

Electrochemical Oxidations of Arylmethanes Investigated in Micro Reactors Organic synthesis 85 [OS 85] Oxidation of4-methoxy toluene to 4-methoxy benzaldehyde... 

OS 85] [R 33] ]P 65] Using conducting salt (0.01 M) in a micro reactor yields a current efficiency of 60-65%, whereas operation without any salt has an efficiency of 96-98% [69]. For conventional electrochemical processing of 4-methoxybenzalde-hyde, an efficiency of49-54% is reported (Figure 4.94). 

Electrochemical Decarboxylations Investigated in Micro Reactors Organic synthesis 86 [OS 86] Electrochemical cecarboxylation of D-gluconic acid... 

An electrochemical reaction, the reduction of benzoquinone, is exemplarily described. An electrochemical micro structured reactor is divided into a cathode and anode chamber by a Nafion hollow-fiber tube. The anode chamber is equipped with a platinum electrode and the cathode chamber contains the analyte and carbon or zinc electrodes. Current density and flow rate are controlled to maximize current efficiency as determined by analysis of the formed hydroquinone by an electrochemical detector. Hydroquinone is extracted subsequently in a micro extractor from the resulting product stream [84],... 

Watts P, Haswell SJ, Pombo-Villar E (2004) Electrochemical effects related to synthesis in micro reactors operating under electrokinetic flow. Chem Eng J 101 237-240... 

Reactor 30 [R 30] Electrochemical Diaphragm Micro Flow Cell... 

Reactor 31 [R 31] Electrochemical Capillary Micro Flow Reactor... 

Figure 4.31 Electrochemical capillary micro flow reactor.

Reactor type Electrochemical capillary micro flow reactor Electrode dimensions 30 X 30 X 3 mm ... 

Reactor type Electrochemical sheet micro flow reactor Reaction medium layer depth 600 pm... 

Figure 4.32 Electrochemical sheet micro flow reactor.

Reactor type Electrochemical plate-to-plate micro flow reactor Reactor volume 35 pi... 

Matlosz, M., Vallieees, C., Micro-sectioned electrochemical reactors for selective partial oxidation, in Eheeeld,... 

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