Removal of NO_x from Flue Gas with Iron Filings Reduction Following Complex Absorption in Ferrous Chelates Aqueous Solutions

Abstract

A novel process for removal of nitrogen oxides (NOx) from flue gases with iron filings reduction following complex absorption in iron-ethylenediaminetetraacetic acid aqueous solution is proposed. The reaction mechanism involved in the process is discussed briefly. The parameters influencing the process, including the concentration of ferrous chelates, initial pH, amount of iron filings, temperature, flow rate of the flue gas, and inlet nitric oxide concentration and oxygen content of the flue gas, are researched in detail. The optimal NOx removal conditions are established. The regeneration and circular utilization of the absorption solution also is studied.

Kinetics of FeIIIEDTA complex reduction with iron powder under aerobic conditions

“…Then, the pH value was adjusted by H 2 SO 4 and NaOH solution. Finally, 1-2 mL of the reaction solution was sampled out and analyzed for the concentration of Fe(II) at specic time intervals: 0.5, 3,6,9,12,15,20,25,30,35,40, 50 and 60 min.…”

“…The results showed Zn and Al powders can effectively act as reducing agents to regenerate Fe II EDTA solution and Sn was not recommended. Fe powder is also a strong reducing agent and can regenerate Fe II EDTA 25. Compared to other metal powders, Fe powder is a cheap and non-toxic reactant and can be obtained easily.…”