Electrolytic Regeneration process

CEER process — (Capenhurst electrolytic etchant regeneration process) Electrochemical process for continuous copper removal from printed circuit board etching solutions employing either cupric chloride or ammoniacal etchant. In a cell divided by a cation exchange membrane the etching process is essentially reversed. In case of the cupric chloride etchant the etchant solution is pumped to the anode, the processes are at the... 

The required recycling of the lead is disadvantageous, and electrolytic procedures have been developed. One process involves electrolysis of NaAlEt4 with a lead anode and mercury cathode the sodium formed can be converted into NaH and the electrolyte regenerated ... 

Demineralization by ion exchange usually involves chemical regeneration of the resins with strong acid or alkali solutions. Weaker electrolyte regenerants are sometimes employed such as solutions of carbon dioxide, ammonia, or lime as demonstrated by various novel processes such as Desal and Carix for the partial demineralization, or desalination, of brackish waters. The increased dissociation of the salt forms of weakly functional cation and anion exchange resins at increased temperatures is the basis of the Sirotherm process which uses alternate... 

In the course of ECM, as a result of electrochemical reactions proceeding on electrodes and chemical reactions proceeding in the IEG, the electrolyte composition changes. This can impair the ECM performance and lead to environmental pollution. In many works, for example [107-117], these processes are studied and the methods of electrolyte regeneration and prevention of environmental pollution are developed. 

In this process, oxide fuel is dissolved in a molten chloride salt mixture through which Q2-HCI gas is flowing. Dissolved uranium and plutonium are then recovered as oxides by cathodic electrodeposition at 500 to 700°C. The process was demonstrated with kilogram quantities of irradiated fuel, with production of dense, crystalline UO2 or UO2-PUO2 reactor-grade material. Difficulties were experienced with process control, off-gas handling, electrolyte regeneration, and control of the plutonium/uranium ratio. Development has been discontinued. 

Pfeifer V.F., Sohns V.E., Conway H.F., Lancaster E.B., Dabic S., Griffin E.L., 2-Stage process for dialdehyde starch using electrolytic regeneration of periodic acid, Ind Eng. Chem., 52, 1960, 201-206. 

In the continuous electrolytic regeneration of cupric chloride etchant the cuprous chloride is oxidised anodically in a cell while the cathode of the cell recovers the copper as a solid flake deposit. The cell, developed by the Electricity Research Council in the UK is divided by a membrane which limits the transport of copper ions, which are in fact complexed, probably mainly as CuCl3 . An economic analysis of the process realised a two year payback on the capital investment. In the case of alternative etchants, such as ferric chloride, continuous regeneration is also feasible. 

In their earlier studies, the group in Manchester added a sodium chloride electrolyte to the adsorbent during the regeneration process [25-27]. However, recent work has shown that the high conductivity of the adsorbent enables effective regeneration to be achieved without the need to add electrolyte to the anode compartment [29-31]. 

Oxidation of an Aldose to the Corresponding Aldonic Add, Bromine or nitric acid are the main oxidants, the latter under mild conditions. The best yields are obtained by the use of bromine in a slightly acid buffered solution (pH 5-6) (see p. 340). The products are generally isolated as the metallic salts by direct crystallization from the reaction solution or by precipitation into ethanol. Yields as high as 95% have been reported in the case of glucose. Commercially the indirect use of bromine as an oxidant is employed in the electrolytic oxidation process with calcium bromide as a catalyst the constant regeneration of free bromine in the solution allows a very economical operation. In the case of rhamnose, the oxidation product can be isolated directly as the lactone this is one of the few cases for which recourse to metallic salts is not necessary. 

Electrode reactions. Malodorous materials can be removed from industrial stack gases by oxidation to harmless products. One possible process is oxidation in acid solution by CeOH + (which is reduced to Ce ), followed by electrolytic regeneration of CeOH + with H as a byproduct, (a) Write four partial equations for these processes, using as the pollutant acrolein, C3H4O, which is oxidized to CO2 and H. (b) Write the equation for the overall process, (c) How many coulombs are needed to dispose of 1.00 kg of acrolein ... 

Electrodialysis Regeneration XAIJ Process, 560 Electrolytic Regeneration tone WebsterAonks) Process, 561 Zinc Oxide Process, 562 Citrate Process, 563... 

Electrolytic Regeneration (Stone Webster/lonics) Process... 

Electrochemical Process. Several patents claim that ethylene oxide is produced ia good yields ia addition to faradic quantities of substantially pure hydrogen when water and ethylene react ia an electrochemical cell to form ethylene oxide and hydrogen (206—208). The only raw materials that are utilized ia the ethylene oxide formation are ethylene, water, and electrical energy. The electrolyte is regenerated in situ ie, within the electrolytic cell. The addition of oxygen to the ethylene is activated by a catalyst such as elemental silver or its compounds at the anode or its vicinity (206). The common electrolytes used are water-soluble alkah metal phosphates, borates, sulfates, or chromates at ca 22—25°C (207). The process can be either batch or continuous (see Electrochemicalprocessing). 

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