Process for removing SO2 and NOx from gases

摘要

A process for removing SO2 and NOx from waste gas and recovering sulfur comprising scrubbing the waste gases with a water slurry of FeS in the presence of FeSO4 and Na2SO4. SO2 is captured by the formation of FeS2 and FeSO4 in the scrubber. By thermal regeneration in a reducing atmosphere the FeS2 is converted to FeS and Na2SO4 to Na2S. The FeS is recycled to the scrubber. The Na2S is returned to the system reacting with FeSO4 to form Na2SO4 and FeS. The last reaction reduces the amount of FeSO4 entering the regenerator where by an undesirable side reaction, it may be partially converted to SO2 and Fe3O4.