(2) Introduction or Desulfurizing Equipment

3.progress in Technology-Based Controls

During the 1970’s, dramatic improvements in the performance of flue-gas desulfurization units as a result of technological advancement has prompted each plant affiliated to the petrochemical complexes to introduced them. Yokkaichi was one of the cities most keenly coping with pollution problems, possessing the greater part of Japan’s large-scale desulfurizing units including the scrubber-a device that removes S02 and dusts from flue gas-established in 1974 which was Japan’s largest at that time.
After that, Yokkaichi had 16 units of flue-gas desulfurizing equipment, which are classified as magnesium hydroxide process (x10), lime-gypsum process (x3), dilute sulfuric acid-gypsum process (x1), sodium sulfite process(x1), and catalytic reduction process (x1). Meanwhile, completed techniques for desulfurization, denitrification and dust removal have permitted the use of coal as fuel, which had been formerly constrained by environmental concern. Accordingly, 3 coal-fire boilers were installed in the city after 1990.