Guidelines for Choosing Cell Technologies

MEMBRANE-CELL TECHNOLOGIES 5.5.1. Guidelines for Choosing Cell Technologies 

In the early 1990s, membrane-cell technology was available from seven or eight suppliers. However, there are now only five suppliers of ion-exchange membrane cells. They are Asahi Kasei, Chlorine Engineers, ELTECH, Uhde, and INEOS Chlor (formerly ICI). Both monopolar and bipolar cells are available from these cell manufacturers, but bipolar cells have become more popular in recent years. 

The choice is generally based on overall capital costs, energy consumption, and operating costs over the life of the cell. These issues are discussed below. 

The dominant role of energy consumption in chlor-alkali economics makes it the most important aspect of cell performance. If one type of cell can offer substantially lower energy consumption than others, it will have a major advantage in any techno-economic comparison. This fact is the single most important reason for the ongoing conversion of the industry to membrane cells. 

A glance at Table 5.4 shows this to be the case. While the percentage differences in energy requirements may be small, we have seen examples in this book of the economic importance of some of these small differences. A change of 20 kW hr ton in an 800-tpd plant operating 350 days/year represents 5.6GWhr year. At 30 MW hr , the cost is 168,000/year. 

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