This work is focused on the investigation of the effects of inorganic additives for carbon dioxide absorption in a liquid solvent containing potassium carbonate. Incorporating the kinetics of the main reaction steps, we considered the interactions between the governing transport mechanisms for determining the effects of gas and liquid outlet temperatures and lean carbonate compositions on outlet carbon dioxide concentration. We estimated the mass transfer coefficient using the surface renewal formalism. Based on the rate-determining steps for the reaction and mass transfer, we developed mathematical models comprising sets of nonlinear differential and algebraic equations, which were solved using the software we developed. Plant data from an industrial unit were used for validating the model, which was subsequently employed for evaluating species concentration profiles, flow rates, temperature, and pressure in the absorber. The effects of the types of promoters, pressure, temperature, and concentration profiles of the promoters were estimated to evaluate the performance of the absorber.