The report gives results of a study of Japanese government efforts to regulate SOx emissions: the efforts were prompted by serious air pollution problems in Japan during the 1960s. Several technologies are being developed including production of low sulfur gas from coal, fuel desulfurization, and fluidized bed combustion. However, predominant methods currently used for SO2 control in Japan are burning low sulfur fuels and flue gas desulfurization (FGD). Development and application of FGD technology in Japan has preceded similar development in other countries, resulting in a significant reduction in ambient SO2 levels. The stringent, daily average ambient standard of 0.014 ppm has almost been achieved. Several types of FGD systems are currently in use in Japan, including wet lime/limestone, indirect and modified lime/limestone, regenerable, and simultaneous NOx/SOx. These processes have been operated satisfactorily on a commercial scale. Both SO2 removal and operability are typically over 90%. Removals and operabilities of 98-99% can be achieved at higher costs.

Prepared for U.S. Environmental Protection Agency, Office of Research and Development under contract no. 68-02-2161, program element no. INE624. Nov. 1978. Includes bibliographical references.