DENITRATING METHOD OF EXHAUST GAS

摘要

PURPOSE:To efficiently convert the NOX in exhaust gas to N2 by subjecting the exhaust gas to oxidation treatment to convert NOX to NO2 then controlling the dissolved O2 in the alkaline scrubbing liquid in which said NO2 has been fixed to approximately zero, and causing denitrification reaction with denitrification germs. CONSTITUTION:The exhaust gas is subjected to oxidation treatment preferably by an O3 oxidation method to convert the NOX in the exhaust gas to NO2. In this case, O3 is added in such a manner that O3/(NO is NOX) becomes 0.8-1.0. Next, the exhaust gas after the oxidation treatment is scrubbed with the alkaline scrubbling liquid of 8-10pH added with Na2SO3 as a reducing agent, whereby the NO2 is absorbed thereon. Next, alcohol (e.g.; methanol) is added to the scrubbing liquid having been absorbed and fixed NO2 so as to make CnH2n+1OH/NOX 1/n, after which the dissolved O2 is controlled approximately to zero. Next, denitrification germs (e.g.; pseudomonas denitroficans) are added to the scrubbing liquid of this state to cause denitrification reaction, whereby the NOX is converted to N2 and is made pollution-free without inducing secondary pollution such as eutrophication.