Evaluation of FeIIEDTA‐NO reduction by thiourea dioxide in NO removal with FeIIEDTA

Abstract

AbstractReducing FeIIEDTA‐NO is key for NO absorption with FeIIEDTA absorbent. In this work, the reducing agent thiourea dioxide (TD) was for the first time employed for reducing FeIIEDTA‐NO. The behavior and kinetics of reducing FeIIEDTA‐NO with TD had been examined with different pH value, varied TD concentrations, and various temperatures. The results investigated that FeIIEDTA‐NO reducing rate rose with pH value increasing as well as elevated temperature. The reaction order of FeIIEDTA‐NO by TD was proved to be 2 on FeIIEDTA‐NO. Meanwhile, activating energy, activating entropy, and activating enthalpy of reducing FeIIEDTA‐NO by TD were separately calculated to be 49.583 kJ mol−1, −64.956 J k−1 mol−1, and 46.943 kJ mol−1. The simultaneous reduction of FeIIIEDTA and FeIIEDTA‐NO by TD was investigated. Results showed that TD was more powerful in reducing FeIIIEDTA and FeIIEDTA‐NO compared with other reduction systems. Finally, nitric oxide removal experiment illustrates that TD can remarkably strengthen the NO removal with FeIIEDTA solution. These theoretical findings could provide constructive suggestions for industrial tail gas denitrification employing associative FeIIEDTA and TD system.