Published: June 1992
Chlor-alkali producers around the world--in the major industrialized countries in particular--are pondering the balance between sagging demand for chlorine and strong demand for caustic soda. The former is caused by increasing environmental pressure in the following major sectors:
- Dioxin generated during pulp bleaching with chlorine has forced the pulp and paper industry to switch from chemical bleaching to chemi-thermal mechanical bleaching, replacing chlorine with hydrogen peroxide.
- Serious depletion of ozone layers has caused the major industrialized countries to totally phase out CFC production by 1995-1996, four to five years ahead of the deadline set by the 1990 internationally approved Montreal Protocol.
- Laws in Western Europe have been proposed to restrict the use of PVC for food and nonfood packaging.
This report presents a comprehensive review of technology and economics for the production of primary chlorine by electrolysis of brine in the membrane cell, diaphragm cell, or mercury cell processes, and production of secondary chlorine by catalytic oxidation as well as electrolysis of HCl. Also presented are preliminary economics for process conversion and retrofit from either mercury cells or diaphragm cells to membrane cells.