Macro-kinetics of amino-hydroxyurea decomposition by NO₂ and O₂ in a nitric acid solution

Amino-hydroxyurea (HSC) has shown excellent performance and application prospects in spent fuel reprocessing. However, its residue affects the subsequent separation process. Introducing the homologous gases NO₂ and O₂ is an effective way to solve this problem. A macroscopic reaction kinetic model for the gas-liquid reaction was established based on the film-penetration theory. By fitting the experimental data to the model, key parameters such as the reaction rate constant k ₁ and the mass transfer constant of NO₂ k _NO2,G were obtained. Similarly, the characteristic parameters of the gas-liquid reaction, such as the Hatta number γ, the enhancement factor E, and the penetration time θ, were analyzed to characterize the gas-liquid reaction process and the intensity of the absorption of reaction gases NO₂ and O₂ in the liquid phase.