In this study, the mass transfer rate for NO_x-SO₂-CO₂ absorption using alkaline solid wastes in a HiGee RPB towards a green process intensification was determined from the theoretical model.

Technology Overview
Green process intensification for simultaneous removal of NO_x-SO₂-CO₂ was proposed. Enhancement on mass transfer of NO_x-SO₂-CO₂ absorption was evaluated. Effects of key operating parameters on mass transfer rate were determined. Favorable energy consumption can determine a better mass transfer performance. Enhancement factor of NO_x-SO₂-CO₂ removal was identified by graphical presentation.

Applications & Benefits
Although a green process intensification of simultaneous removal of NO_x-SO₂-CO₂ using alkaline solid wastes as solvent in a RPB was successfully demonstrated, the priority research directions would be focused on the efficacy of continuous operation, treatment of higher acid gas pollutants concentration and techno-economic evaluation of the integrated Higee air pollution control technology.

Abstract：
In order to intensify the gas-liquid absorption processes in the field of energy and environment, high-gravity rotating packed bed (HiGee RPB) has been successfully applied in the multiple air pollutants abatement and CO₂ capture by mineralization. Since the mass transfer and chemical reaction through gas-liquid absorption were found to be the key factors affecting acid gas removal, a mass transfer model based on the two-film theory for simultaneous removal of NO_x-SO₂-CO₂ in an RPB was developed in this study. The mass transfer parameters including overall gas-phase mass transfer coefficient (K_Ga), height of a transfer unit (HTU), liquid mass transfer rate (k_L) and enhancement factor (E) were theoretically determined from the experimental data. The effect of key dimensionless operating factors such as high gravity factor (β), gas-to-liquid ratio (GLR), and liquid-to-solid ratio (LSR) on mass transfer parameters were evaluated. Based on the results obtained in this study, the enhancement of high gravity filed on mass transfer and removal efficiencies of NO_x and CO₂ were significantly higher than that of SO₂. It was inferred that the carbonation reaction could compensate the removal efficiency of acid gaseous pollutants at the lower mass transfer rate. The relationship between mass transfer rate and energy consumption for the multiple air pollutant control via a HiGee process was established. The favorable operating factors for NO_x-SO₂-CO₂ simultaneous removal in an RPB were suggested as β of 233.8, GLR of 69.5 and LSR of 40.

Enhanced performance on simultaneous removal of NO_x-SO₂-CO₂ using a high-gravity rotating packed bed and alkaline wastes towards green process intensification
Author：Chen T.-L.,Chen Y.-H., Chiang P.-C.
Year：2020
Source publication：Chemical Engineering Journal  Volume 393, 1 August 2020, 124678
Subfield Highest percentage：99%    Industrial and Manufacturing Engineering    #3/336

https://www.sciencedirect.com/science/article/pii/S1385894720306690