Performance evaluation and process simulation for synergetic removal of NOx, CO2 and PM using green alkaline solution in a high-gravity rotating packed bed

The high-gravity rotating packed bed (HiGee RPB) developed here can simultaneously remove multiple air pollutants using alkaline solution, thus achieving the flue gas deep purification. The electric-arc-furnace reduction slag (EAFRS) leachate was then used as the alkaline absorbent in HiGee RPB for assessing the removal efficiencies of nitrogen oxide (NOx), carbon dioxide (CO2) and particulate matters (PM) from flue gas. The results indicated the changes to the CO2 capture was enhanced by increasing the initial PH value of the alkaline solution. In contrast, this value has no significant influence on NOx removal. The suitable NOx removal efficiency ranged from 90.9% to 97.09% at the liquid-to-gas (L/G) ratio of 0.01 and high gravity factor of 58.9 to 368. The precipitated calcium carbonate gained from carbonation via HiGee process exhibited similar physical properties to commercial products. In addition, 95.9% of PM removal efficiency was achieved at the L/G ratio and high gravity factor of 0.03 and 235.4, respectively. This treatment furthermore demonstrated a high efficiency for PM collection of over 90% and balanced the energy consumption. Based on the result, an Aspen simulation and a preliminary cost-benefit analysis were carried out to develop a mass-balance model for this system and determine the favorable operating conditions.