Absorption kinetics of NO from simulated flue gas using Fe(II)EDTA solutions

Abstract

The absorption of NO encountering flue gases in aqueous solutions of Fe(II)EDTA was determined using a semi-batch stirred tank with a plane gas–liquid interface at 50 °C. The concentrations of NO, SO 2 and O 2 in the feeding stream were 300–800 ppm, 500–2200 ppm and 0–20%, respectively. The pH value of the Fe(II)EDTA solutions varied from 3 to 11. The concentrations of Fe(II)EDTA were maintained between 0.01 and 0.05 M. Experiments were performed to evaluate the effect of operating parameters on the NO absorption rate, the reaction kinetics of the reactants in gas and liquid phases, and the effect of competition between various reactants on the mass transfer rate in the NO removal system. Results indicate that the average reaction rate constant is 3.70 × 10 7 M −1 s −1. Adding NaOH does not increase the absorption capability of Fe(II)EDTA. The presence of O 2 decreases the NO absorption rate with Fe(II)EDTA. The absorption rate of NO with Fe(II)EDTA decreases at low concentrations of SO 2, but increases at high concentrations.