Electrolytic reactor scale

Scale- Up of Electrochemical Reactors. The intermediate scale of the pilot plant is frequendy used in the scale-up of an electrochemical reactor or process to full scale. Dimensional analysis (qv) has been used in chemical engineering scale-up to simplify and generalize a multivariant system, and may be appHed to electrochemical systems, but has shown limitations. It is best used in conjunction with mathematical models. Scale-up often involves seeking a few critical parameters. Eor electrochemical cells, these parameters are generally current distribution and cell resistance. The characteristics of electrolytic process scale-up have been described (63—65). 

Change in the scale of a reactor will change its performance. This calls for suitable allowances in process design knowledge of the probable variation in performance of units on a change of scale is required. For this we need mathematical models supported by key experimental trials. This section describes the procedures necessary to scale up an electrolytic reactor. 

The heat exchange between an electrolytic reactor and its surroundings changes on scale-up. The electrode area of a reactor is usually held constant and thus on scale-up the increase in electrode area is proportional to the increase in volume. However, the surface area for heat transfer does not increase in proportion to the volume in most configurations. It is harder to... 

It is common in the scale-up of electrolytic reactors to increase the number of smaller modules rather than go for an increase in electrode size. This may appear more costly in capital investment, but it is often more than compensated for by more efficient maintenance and process operation. Design limitations often make this the only choice. 

Decomposing water requires 242 kilojoules (kJ) per mole, a great deal of energy. Indeed, the reverse reaction is an H2/O2 torch, which releases a great deal of energy. We could drive the reaction with electricity. You have probably seen this demonstrated on a small scale in secondary school. We thus add an electrolytic reactor to produce H2 ... 

Electrochemical cells have also been proposed for carbon that employ a eutectic molten salt mixture of Li2C03 Na2C03or LiCl-CaCl2-CaC2 as the electrolyte. A diffusion-type meter has also been developed for both small-scale and reactor sodium . 

Currently, adiponitrile is the only organic chemical produced in large quantity (108 kg/yr) by an electrochemical route. Other smaller-scale products include gluconic acid, piperidine, and p-aminophenol. Electroorganic syntheses in supercritical organic electrolytes have been demonstrated in bench-scale reactors. Production of dimethyl carbonate from the mixture-critical region was performed. There are at least a dozen electroorganic processes that are... 

By 2040-2050, natural gas reserves will be in very short supply, and the production of coal will quite likely be approaching peak production levels.19. While nuclear power plants are a source of large scale electricity generation, there exist major concerns regarding uranium supply (without breeder reactors), safety, waste disposal, and nuclear weapon proliferation. Therefore, it is prudent to explore the economic feasibility of other fuel sources such as PV electrolytic H2 for centralized, electricity generating plants. 

Closely related to the above is a new process (301) in which ammonia and fluorine are passed into a reactor containing NH4F-HF at slightly above its melting point (125°C). Under these conditions the molten salt serves to moderate the reaction, which is essentially that between the two gases. It is claimed that the trifluoride produced is of high purity, and this appears to be an alternative to the electrolytic method for preparing the gas on a technical scale. 

Although nitrogen trifluoride can be prepared by several chemical procedures, only two methods are technically and economically feasible for a large-scale production The electrolysis of molten ammonium acid fluoride and the direct fluorination of NH3 in the presence of molten NH4F [71]. The direct fluorination is carried out in specially designed reactor [72] in which NF3 is produced by the reaction of F2 with NH3 in the presence of molten ammonium fluoride. As no hydrogen is generated in the direct fluorination process, it is considered safer than electrolytic process. In the later process, NF3 is produced at the anode and H2 at the cathode. 

Fig. 4). The utility of the in situ electrolytic reduction method was demonstrated with good results on a small scale for a breeder reactor fuel containing 15% Pu (17). Electrolytic reduction studies were reported in France (18), the Soviet Union (19,20), the United Kingdom (27), and China (37). 

When formulating an electro-organic synthesis on a laboratory scale, the proper choice of reactor, electrolyte composition, and electrode materials must be made. 

The largest exchange current density, j0, of the reaction has to be selected, if possible, since economic limitations are always prevalent in scaled-up engineering. However, with the development of nanodispersed substrates and carbon-supported metal catalysts, this limitation becomes a secondary consideration. At this point, it is important to say that most of the reported values of j usually refer to simple reactions on pure metal substrates using different shapes of electrode designs in a certain and single electrolyte. Thus, the measurement of the real j0 value at select industrial conditions of the electrochemical reactor has to be performed that is, experimental measurements cannot be avoided [4,5]. 

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