| 摘要 |
<p>PURPOSE:To prevent the lowering in desulfurization efficiency, by a method wherein O2-containing gas is introduced into the Ca-containing absorbing liquid of the zone contacting with waste gas containing SO2, HF, HCl and soot to hold the concn. of sulfite in the absorbing liquid to 5mmol/l or less. CONSTITUTION:The waste gas 1 containing SO2, HF, HCl and soot from a boiler is supplied to an absorbing part 6 and contacted with an absorbing liquid 8 containing a Ca-compound to be subjected to desulfurization and dust removal treatment while the waste gas 2 after treatment is exhausted. Air 3 is introduced into the absorbing liquid 8 and SO2 in the waste gas 1 is absorbed by the absorbing liquid to be immediately oxidized and a sulfate ion is formed to hold the concn. of sulfite to 5mmol/l or less. The absorbing liquid 8 is supplied to a solid-liquid separator 7 to separate gypsum 5 and CaCO3 4 being an absorbent is charged in the filtrate while the regenerated absorbing liquid is recirculated to the absorbing part 6. NaOH is supplied from a line 9.</p> |
