CO2 capture using MEA (monoethanolamine) aqueous solution in coal-fired power plants: Modeling and optimization of the absorbing columns

The CO2 capture based on the MEA (monoethanolamine) absorption has been proved to be a practical and alternative method for the post-combustion CO2 capture. It is of benefit to the energy conservation of CO2 capture system to clarify the impacts of the absorbing column parameters on the system performance. Based on the representative elementary volume method and pseudo-single-liquid model, the computational model of CO2 absorption into the MEA solution in the absorbing column was developed, in which the gas phase flow was taken into account. The modeling and computational methods were validated by the comparison between the experimental data and numerical results. An industrial-scale absorption column was investigated, and the influences of the height, operating pressure and the packing materials of the absorbing columns on the mass transfer performance and energy consumption were obtained. The results show that the optimal operating pressure is the atmospheric pressure and the optimal height of the absorbing columns is about 8 m in this work. For the minimum energy consumption, the surface area per unit volume and the porosity of the packing materials should be as big as possible.