Chloralkali electrolysis process membranes

The chloralkali electrolysis process is by far the most important source of electrolytically generated hydrogen because hydrogen from alkaline or membrane water electrolysis usually cannot compete with hydrogen from steam reforming followed by shift reaction and PSA purification and therefore is not performed on a large scale (62, 40). 

This process has been used to make functionalized perlluorovinyl ethers [e.g., F2C = CF0CF2CF(CF3)0CF2CF2S02F] which are copolymerized to form fluorinated membrane materials (Nafion, Flemion), which arc important in chloralkali electrolysis. ... 

Production of caustic soda solution. In 1998, the worldwide production capacity was about 54 million tons per year. Ca. 96-98% of this amount is produced by chloralkali electrolysis [313). The three processes are described in detail in chapter 5 (Mercury Cell Process), chapter 6 (Diaphragm Process) and chapter 7 (Membrane process), a comparison of the relative qualities is given in chapter 9. 

A mixture of hydrogen and chlorine gas, eventually in combination with air, can be very explosive if one of the components exceeds certain limits. In chlorine production plants, based on the electrolysis of sodium chloride solutions, there is always a production of hydrogen. It is, therefore, essential to be aware of the actual hydrogen content of chlorine gas process streams at any time. There are several places in the chlorine production process where the hydrogen content in the chlorine gas can accumulate above the explosion limits. Within the chloralkali industry, mainly two types of processes are used for the production of chlorine—the mercury- and the membrane-based electrolysis of sodium chloride solutions (brine). 

To the extent that it is discernible in the products and processes, appropriate aspects have been incorporated in the revision, for example see membrane technology in the chloralkali and hydrochloric acid electrolysis. 

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