Overview of the Chlor-Alkali Industry

The world production capacity of chlorine reached 53 million tons in 2002 from approximately 22 million tons in 1970 [1-7] and is expected to increase to 65 million tons by the year 2015 [8]. In this chapter, the major manufacturing processes and the factors affecting the growth pattern of the chlor-alkali industry are presented. 

Chlorine is sold as a gas or a liquid, and caustic soda is sold as 50% or 73% solution, or as anhydrous beads or flakes. There is also a significant market for caustic soda in the concentration range of 10-25%. The caustic soda product is designated by the manufacturing technology used, namely mercury, diaphragm, or membrane cells. More than 95% of the chlorine and 99.5% of the caustic in the world are produced by these cell technologies. About 0.5% of caustic soda is made chemically from soda ash, and KOH accounts for 2.5% of the caustic produced in the world. 

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This chapter gives an overview of the chlor-alkali industry in Australia and examines the background to the decision to replace the mercury cell plants. It then describes the new plants, their technical and safety features and the process used to arrive at the selection of the technology supplier. 

In spite of their importance, relatively little information exists in the literature concerning the fundamental physicochemical properties of these membranes. This is due both to their proprietary nature and to the rapid growth of the technology. Also, what information is available is dispersed in a wide range of sources, ranging from the literature specializing in macromolecules to that devoted to the chlor-alkali industry. This work attempts to provide, in one volume, an overview of both the fundamental properties and the technological aspects of the field. 

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