Can Fenton reagent denitrate?
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Can the Fenton reagent, composed of ferrous sulfate and hydrogen peroxide, be used for flue gas denitration? According to relevant literature {CNKI: Master’s thesis from Shanghai University of Electric Power}, Fenton reagent reacts rapidly with NOx, exhibiting high reactivity; the denitration efficiency can reach over 80%. The molar ratio of ferrous ion to hydrogen peroxide is 1:150~200. However, in a project for denitrification of acid-making exhaust gases, I used Fenton’s reagent as a denitrifying agent, and as a result, the NOx levels increased instead of decreasing. It rose rapidly from an initial level of 300 mg/m3 to over 400 mg/m3. I was completely puzzled at the time, but after seeking advice and researching, I found that it was iron reacting with nitric acid to produce dinitrogen monoxide (N2O). Moreover, when preparing the Fenton reagent, an extremely low molar ratio of ferrous ion to hydrogen peroxide was not achieved; a large excess of ferrous ions was used. I sincerely seek advice from professionals or those with similar experience here: can Fenton’s reagent indeed be used as a chemical for denitration? If possible, what are the prerequisites? (Is an extremely strict low molar ratio required for ferrous ion and hydrogen peroxide? )
There are methods that use hydrogen peroxide for denitration, and it is said that their effectiveness is rather average. In your case, there’s also a reducing agent involved, but ferrous ions do not have very strong reducing properties (they are not effective at reducing NOx to nitrogen). Hydrogen peroxide, on the other hand, is a substance with both strong oxidizing and reducing properties, so it cannot absorb much NOx