Electrical field effect on CO2 absorption and chemisorption in a rectangular bubble column by COMSOL

Raman Kumar Singh1, Prakash Chandra Ghosh1, Venkatasailanathan Ramadesigan1
1Department of Energy Science and Engineering, IIT Bombay, Mumbai, India
Published in 2023

The chemisorption and absorption of CO2 bubbles have been extensively studied and modeled in literature. CO2 gas is converted into aqueous CO2, which produces OH-, HCO3- and CO32- - ions in the solution. In this study, a 3D CO2 bubble column is simulated using COMSOL Multiphysics, implementing two models: a CO2 bubble column without an electrical field and a CO2 bubble column model with an electrical field. The first model is developed using the Euler-Euler model and simulated using Bubble flow and Dilute solution theory module in COMSOL, validated against existing literature. The second model builds upon the first model by considering the electrostatic interaction between the charged species and the electrical field, employing the Nernst-Planck equation. Simulation results from the second model indicate that the presence of an electrical field significantly impacts the CO2 chemisorption process in the rectangular bubble column. The applied field alters the distribution of charged species, influencing concentration gradients, and enhancing mass transfer rates. A parametric study is conducted on mesh refinement, flow rate, and applied electric field. The findings of this study can inform the design of novel CO2 capture systems, offering potential avenues for mitigating greenhouse gas emissions and advancing sustainable energy practices.