INVESTIGATION ON REMOVAL OF NO_χ AND SO_2 FROM FLUE GAS BY COMBINED OZONE WITH ABSORPTION AND BY-PRODUCT TREATMENT

摘要

The combination of ozone with washing tower and an absorption products recovery system was utilized for removal of NO_χ and SO_2 from flue gas. In our previous studies, more than 90% NO can be oxidized by ozone. In this study, three kinds of absorbents, Na_2SO_3, CaSO_3 and Ca(OH)_2, were evaluated for simultaneous absorption of NO_2 and SO_2 in the wet scrubbing. It was found that NO_2 absorption efficiency was increasing with S(IV). Effect of different concentration of CaSO_3 on NO_2 absorption was investigated. Results show that nearly 70% NO_2 can be absorbed in calcium sulfite slurry. Furthermore, NO2 absorption efficiency is increasing to 85% in the sulfite with assistant of MnSO_4. In the meantime, the absorption efficiency of SO_2 is always nearly 100%. A new system is built for recycling NO_2 absorption products and purifying the waste water, which has the advantages of low investment and operating cost.