Chlorine-alkali electrolysis

As was noted above, functional fluoropolymers produced by copolymerization of fluoroolefins with functional PFAVE have several unique properties, with the main disadvantage of these materials being the extremely high cost of functional monomers and the resulting high cost of the functional polymers produced from them. The fact that they are so expensive limits their wider industrial application in other fields such as catalysis and membrane separation, except for chlorine-alkali electrolysis and fuel cells, where the only suitable materials are fully fluorinated polymers because of the extreme conditions associated with those processes. 

Chlorine-alkali electrolysis is the largest application of such materials as these are the only materials that can be used successfully in this process. As this process provides alkali of better quality than the conventional diaphragm process, and is much more attractive environmentally than the mercury process, its part in industrial world manufacturing of alkali is expanding rapidly. 

With respect to the German case study used in Chapter 14 to discuss the build-up of a hydrogen infrastructure, Fig. 10.9 shows where surplus hydrogen capacities (from chlorine-alkali electrolysis) exist in Germany. If these capacities are added up, the resulting total amount is about 1 billion Nm3 per year (around 4% of total German hydrogen production). 

Dormagen and from chlorine-alkali electrolysis in Leverkusen, to feed this into the hydrogen pipeline network of the... 

Hydrogen also occurs as a by-product of the chemical industry (for instance, chlorine-alkali electrolysis) and is already being used thermally. This represents another (cheap) option (where available), because it can be substituted by natural gas, although investments in purification might be necessary. This option is relevant for supplying hydrogen during the initial start-up phase in areas where user centres are nearby. 

X.L. Wang and S. Koda, Scale-up and modeling of oxygen diffusion electrodes for chlorine-alkali electrolysis. 1. Analysis of hydrostatic force balance and its effect on... 

The world production of chlorine amounted in 1983 between 28 and 30 million tons, with an equivalent amount (similar) of caustics. The chlorine-alkali electrolysis consumed in that year 90 billion kWh of electric energy and produced about 10 billion dollars in market value. It represents a striking example of the effect electrochemical science has on technology, since three breakthroughs in recent years have resulted in major improvements in its environmental acceptability and major energy saving. 

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