Modeling of a bubble column for CO₂ removal by absorption with NaOH

CO₂ capture experiments were carried out in a small-scale bubble column reactor using alkaline solutions of sodium hydroxide. The results of the experiments show that a higher NaOH content in the liquid phase and elevated CO₂ concentrations in the gas mixture led to a higher CO₂ removal efficiency. A mathematical model was developed to describe the CO₂ absorption as a function of CO₂ gas inlet and OH^- concentrations at low CO₂ and OH^- concentrations. The CO₂ uptake at high OH^- concentrations (high pH) was accurately predicted by the model, whereas the CO₂ uptake at lower OH^- concentrations could not be predicted with the same accuracy.