Mass transfer of carbon dioxide absorption by monoethanolamine solution with super mini ring contactor

Super mini ring contactor is an alternative of conventional packing in CO2 absorption packing columns. The contactor gives more efficient absorption, hence reducing capital costs. This research modeled and numerically simulated CO2 absorption by monoethanolamine solution with a super mini ring contactor in a single ring unit. The model considered the momentum transfer and the mass transfer coupled with the chemical reaction under isothermal condition. Computational fluid dynamics concept was used to describe the velocities and the flow patterns in the gas and liquid phases. The calculated results were observed in term of the CO2 mass transfer in the bulk gas, the boundary layers and the bulk liquid. The simulation results show that the CO2 concentration in the bulk gas is evenly distributed. The CO2 concentration gradient in the gas phase occurs in the gas boundary layer, in which the concentration decreases from about 7.56 mol/m3 to around 6.7 mol/m3. In the liquid phase, the CO2 concentration drops from about 11 x 10-5 mol/m3 at the interface to almost zero with the reaction rate being approximately-25 mol/m3.s and the CO2 diffusion coefficient in the liquid phase being about 2.1 x 10-10 m2/s.