ABSORPTION OF NO PROMOTED BY STRONG OXIDIZING AGENTS: 1. INORGANIC OXYCHLORITES IN NITRIC ACID

Abstract

Almost quantitative absorption of NO is achieved in nitric acid solutions containing sodium chlorite, sodium hypochlorite, or chlorine gas at temperatures up to 80°C and atmospheric pressure. Experiments are conducted by bubbling various mixtures of NO, NO₂ and O₂, with the balance N₂ into varying volumes of scrubbing solutions up to one dm³. When scrubbing with acidic NaClO₂, a greenish yellow color is observed in the solution when the gaseous mixture is bubbled into the liquid containing the oxidizing compound. The color is due to the presence of ClO₂ gas, an intermediate active in the oxidation of NO. Results in acidic NaClO or Cl₂ show similar results, except the intermediate that actually promotes the oxidation is HClO. These intermediates were identified spectroscopically. Material balances, determined using ion chromatography, show that the only anions in solution at NO breakthrough are NO₃ ⁻ and Cl⁻.

KEYWORDS:

• Absorption
• ClO₂
• HClO
• NO_x
• Oxidation
• Scrubbing

Additional information

Notes on contributors

HENRY SHAW

Author to whom correspondence should be addressed; Phone [phone]