Chlorine from electrolytic process

Commercially, hydrogen chloride is obtained either as a by-product in the manufacture of salt cake from sodium chloride, or by allowing chlorine produced as a by-product in electrolytic processes to react with hydrogen in the presence of activated charcoal. It is also formed as a byproduct in the manufacture of phenol. 

The development of electrical power made possible the electrochemical industry. Electrolysis of sodium chloride produces chlorine and either sodium hydroxide (from NaCl in solution) or metallic sodium (from NaCl fused). Sodium hydroxide has applications similar to sodium carbonate. The ad vantage of the electrolytic process is the production of chlorine which has many uses such as production of polyvinyl chloride. PVC, for plumbing, is produced in the largest quantity of any plastic. 

Among electrolytic processes used to produce materials, we customarily distinguish those in which electrodes are reacting that is, where the metal or other electrode material is involved in the reaction (Chapter 16) from those with nonconsumable electrodes (Chapter 15). A very important industrial process with nonconsumable electrodes is the electrolysis of sodium chloride solution (brine) producing chlorine at the anode and sodium hydroxide NaOH (caustic soda) in the catholyte via the overall reaction... 

This process was developed to transfer essentially all the chlorine from the impure stream. Since this will require, in general, orders of magnitude lowering of the Cl2 concentration, a series of cells will be required to operate at current densities commensurate with the gas phase transport limitation. If this limiting current density is exceeded, H2 will be liberated as the electrolyte is reduced. 

De Nora An electrolytic process for making chlorine and sodium hydroxide solution from brine. The cell has a mercury cathode and graphite anodes. It was developed in the 1950s by the Italian company Oronzio De Nora, Impianti Elettrochimici, Milan, based on work by I. G. Farbenindustrie in Germany during World War II. In 1958 the Monsanto Chemical Company introduced it into the United States in its plant at Anniston, AL. See also Mercury cell. 

Hoechst-Uhde (1) An electrolytic process for generating hydrogen and chlorine from hydrochloric acid. Widely used. 

Schroeder An electrolytic process for recovering chlorine from waste hydrochloric acid. 

The process was complicated by the formation of calcium manganite, CaMn206, known as Weldon mud. Invented by W. Weldon in 1866 and developed at St. Helens from 1868 to 1870. Operated in competition with the Deacon process until both were overtaken by the electrolytic process for making chlorine from brine. Weldon mud has been used as a catalyst for oxidizing the hydrogen sulfide in coal gas to elemental sulfur. 

Probably the most important of these electrolytic processes yielding hydrogen as a by-prodiact is the Castner-Kellner. The primary purpose of this process is to make caustic soda from a solution of brine but both hydrogen and chlorine are produced at the same time. 

In 1800. William Nicholson and Anthony Carlisle decomposed water into hydrogen and oxygen by an electric current supplied by a voltaic pile. Whereas Volta had pruduced electricity from chemical action these experimenters reversed the process and utilized electricity to produce chemical changes. In 1807. Sir Humphry Davy discovered two new elements, potassium and sodium, by the electrolysis of ihe respective solid hydroxides, utilizing a voltaic pile as the source of electric power. These electrolytic processes were the forerunners of the many industrial electrolytic processes used today to obtain aluminum, chlorine, hydrogen, or oxygen, for example, or in die electroplating of metals such as silver or chromium. 

Modern electrolytic processes for obtaining chlorine and caustic soda (NaOH) from salt result in the liberation of enormous quantities of hydrogen. The salt, dissolved in... 

A 1.5276-g sample of CdC underwent an electrolytic process separating all of the cadmium from the sample. The weight of the metallic cadmium was 0.9367 g. If the atomic mass of chlorine is taken as 35.453, what must be the atomic mass of cadmium from this experiment ... 

ALCOA A process proposed for manufacturing aluminum metal by the electrolysis of molten aluminum chloride, made by chlorinating alumina. It requires 30% less power than the Hall-Heroult process and operates at a lower temperature, but has proved difficult to control. Developed by the Aluminum Company of America, Pittsburgh, in the 1970s and operated in Palestine, TX, from 1976 abandoned in 1985 because of corrosion problems and improvements in the efficiency of the established electrolytic process. 

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