Non-equilibrium modeling of CO2 reactive-absorption process using sodium hydroxide-ammonia-water solution in a packed bed column

In this study, CO2 reactive-absorption process is modeled into the NaOH-NH3-H2O solution in an absorption column. A non-equilibrium or rate-based model is used to simulate the process performance, and the predicted results are compared with the experimental data. In this model, the steady and nonlinear film models are utilized for high and low solubility components, respectively. The average relative deviation (ARD%) is decreased from 9.73 to 4.36 by increasing the number of column stages from 20 to 60 in the simulation. On the other hand, the predicted values by the film and enhancement factor models are compared, and it was concluded that the film model was more accurate than the other. The effects of axial position through the column and initial NaOH concentration on the liquid flow rate, mole fraction of components, and temperature of the gas and liquid phases are also investigated. As a main result, the temperature of the liquid phase and the CO2 concentration in the liquid phase decrease by increasing the axial position through the column.