Modeling of NO mass transfer characteristics absorbed in sodium persulfate solution with a bubble reactor

ABSTRACT:

Sodium persulfate solution is considered as an effective wet denitrification medium, however, it is unclear that the influence of the operating conditions on mass transfer characteristics parameters during the absorption of NO with sodium persulfate solution. To determine the key mass transfer characteristics parameters, the specific interfacial area $a$ and the mass transfer coefficients $k_{\mathrm{L}},$ $\mathrm{ }{k}_{\mathrm{G}},$ were determined based on the Danckwerts method during CO₂ absorption in a bubble column. $k_{\mathrm{L}},$ $k_{\mathrm{G}}$ and $a$ were calculated by correlations between the mass transfer coefficients of NO and CO₂. Results showed that the specific interfacial area increased 77.64 m⁻¹, the liquid phase mass transfer coefficient increased 2.49 × 10⁻⁴ m·s⁻¹, and the gas phase mass transfer coefficient increased 0.71 × 10⁻⁵mol·Pa⁻¹·s⁻¹·m⁻² with superficial gas velocity increasing from 0.6 to 1.4 L·min⁻¹. With the temperature of sodium persulfate solution increasing from 293 to 333 K, the specific interfacial area decreased 42.66 m⁻¹, while the liquid phase mass transfer coefficient and the gas phase mass transfer coefficient increased 3.89 × 10⁻⁴ m·s⁻¹ and 1.18 × 10⁻⁵mol·Pa⁻¹·s⁻¹·m⁻², respectively. The experiments results determined the correlations of $a,$ $k_{\mathrm{L}},$ and $k_{\mathrm{G}}$ with the temperature of the absorption phase and the superficial velocity of the gas. It can serve as a guide to the enhancement of the sodium persulfate wet denitrification process.

Keywords:

• Mass transfer coefficient
• gas–liquid specific interfacial area
• gas absorption
• bubble column reactor

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article or its supplementary materials.

Additional information

Funding

This work was support by the National Natural Science Foundation of China (Grant No. U1906232).