Modeling and Simulation of CO2 Absorption into Promoted Aqueous Potassium Carbonate Solution in Industrial Scale Packed Column

<p>This paper aims to develop mathematical model for investigating the CO₂absorption into promoted hot potassium carbonate solution in industrial scale packed column. The absorber is used in a large-scale ammonia plant to remove CO₂ from the process gas stream. The CO₂ is removed from the gas stream by counter-current absorption in two stages column<span style="text-decoration: line-through;">.</span> Lean solution and semi lean solution were fed into the top of upper part column and lower part column, respectively. To represent the gas-liquid system, a rigorous mathematical model based on the two-film theory is considered. The heat effects are taken into account. The model consists of differential mass and heat balance and considers the interactions between mass-transfer and chemical kinetics using enhancement factor concept. The chemical reaction in the liquid phase is based on the bicarbonate ion formation from CO₂ as the rate-determining step. Gas solubility, mass and heat transfer coefficients, reaction kinetics and equilibrium were estimated using correlations from literatures.Therefore, multi-component absorption phenomena were considered in the mathematical model. The model was validated using plant data and was used to compute temperature and concentration profiles in the absorber. The variation in percent CO₂ recovery with respect to changes in some operating variables is evaluated. The effect of various kinds of promoters added into potassium carbonate solution on the carbon dioxide recovery was also investigated.