| 摘要 |
<p>PURPOSE:To provide a flue gas desulfurization method which can solve problems concerning the lowering in the reactivity of limestone due to HC1 absorption in exhaust gas and the oxidation function of sulfite salt. CONSTITUTION:In wet desulfurization using absorbent slurry containing a highly concentrated Cl<-> ion, two units of an absorption tower are installed to attain high functions of desulfurization and sulfite salt oxidation, and the absorbent slurry in the first absorption tower 3 on the upstream side of an exhaust gas passage is operated at a low pH value. The Ca<2+> concentration is reduced by adding an alkaline non-calcium type compound 7 represented by dolomite into the first absorption tower 3, the reactivity of limestone and the oxidation function of sulfite salt are prevented from lowering, the absorbent slurry in the second absorption tower 9 is operated at a high pH value, and an alkaline calcium type compound 10 such as limestone is used as an absorbent.</p> |
