process for cleaning of flue gases and other gases, sulphur oxides, nitrogen oxides and sulfide

摘要

Waste gases contg. S oxide, NOx cpds. and H2S are cleaned immediately after cooling by contacting the gas with a wash fluid to which is added an absorbing substance such as HCl or formic acid. In order to remove practically all NOx cpds. the wash fluid enriched with hydrochloric acid and formic acid is inoculated in addn. with H2O2, and/or Na2O2, and/or KMnO4. The H2O2, and/or KMnO4, and/or Na2O2 is added to the waste gas to be cleaned prior to the addn. of the wash fluid, which is enriched with hydrochloric acid and/or formic acid, by using pref. a separate nozzle and fresh water. Alternatively, after removal of the SO2 compds. the NOx compds. are treated in a separate wash stage with a liq., which is inoculated with KMnO4, and/or Na2O2, and/or H2O2. The method of addn. depends on the quality requirements of the final prod. CaSO4, which may be used in the building industry.