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

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