The absorption kinetics of no from flue gas in a stirred tank reactor with KMnO₄/NaOH solutions

Abstract

Absorptions of NO by neutral and alkaline solutions of KMnO₄ were performed in this study to clarify the reaction kinetics. The experiments were mainly carried out under 50°C, which is the common operating temperature for wet scubbers.

According to the assumption that the absorption of NO was developed under the fast pseudo‐mth reaction regime, which is verified in the experiments, the absorption rate of NO into KMnO₄ solutions is found to be negative half‐order dependent on P_NO and first‐order dependent on [KMnO₄]. The addition of NaOH into the solutions of KMnO₄ would increase the absorption rate of NO. The absorption rate of NO at 25°C is lower than that of 50°C. In the ranges of this study, the absorption rate of NO would not change by changing the gas flow rate and O₂ concentration. NO₂ ^‐ is the dominate ion in the liquid phase for this study. However, the [NO₃ ^‐]/[NO₂ ^‐] ratio increases with the increasing NaOH concentration.

Key words:

• Absorption kinetics
• nitric oxide
• potassium permanganate