Trends of mercury emissions from the Chlor-Alkali industry in EECCA countries

Abstract

The article presents an assessment of the trends of mercury emissions from the chIor-alkali industry in EECCA countries during the period 1990–2006. Factors contributing to the decrease in the atmospheric emissions of mercury, as well as uncertainties surrounding its sources and assessment, are analyzed. The assessment of mercury emissions is based on emission factors and on available data on mercury-cell caustic soda production. Previously developed emission factors for mercury-cell caustic soda production have been revised; high and low emission factors have been calculated taking into account technological advances since 1990. The results show that the range of mercury emissions from the chlor-alkali industry amounted to 22.9–91.8 tons in 1990, and 2.4–19.2 tons in 2006. The median value of mercury emissions has been estimated at 57.3 tons in 1990 and 5.9 tons in 2006. Although mercury emissions decreased by a factor of almost 10 during the period studied, the difference between the high and low values increased by a factor of roughly 2. Among the EECCA countries, Russia's share of total mercury emissions is the largest. Furthermore, its contribution to mercury emissions from the chlor-alkali industry is increasing: in the early 1990s it produced 74% of total mercury emissions in EECCA countries, in 2006 it produced 94%.