Improvement of the Fe-NTA Sulfur Recovery System by the Addition of a Hydroxyl Radical Scavenger

Abstract

The degradation of Nitrilotriacetic Acid (NTA), which results from the oxidation of hydroxyl radicals formed in the process, is a major deficiency in the present Fe-NTA system for the oxidation of hydrogen sulfide to sulfur by air. The degradation of NTA can be slowed down considerably by the addition of a hydroxyl radical scavenger. In this study, a series of inorganic and organic materials was tested as scavengers/inhibitors of hydroxyl radicals in attempts to improve the Fe-NTA system. The results showed that N-methylpyrrolidinone and ethylene glycol could be used as potentially powerful scavengers of hydroxyl radicals to improve the Fe-NTA system.

Keywords:

• Ethylene glycol
• Fe-NTA system
• N-methylpyrrolidinone
• scavenger of hydroxyl radicals

Acknowledgments

We are grateful to the U.S. Filter for financial support.

Notes

^{a a}Including that produced from Na₂S₂O₃ and a calculation based on consumed H₂S.

*Difficult to calculate.

^aIncluding that produced from Na₂S₂O₃ and a calculation based on consumed H₂S.

*Difficult to calculate.