Advanced modelling in performance optimization for reactive separation in industrial CO2 removal

A comprehensive model has been developed for investigating the absorption of carbon dioxide in hot potassium carbonate solution with boric acid catalyst. The model consists of the kinetics of key reactions and considers the interactions between mass-transfer and chemical kinetics. The mass-transfer coefficient was calculated using the surface renewal theory and the chemical reaction in the liquid phase is based on the bicarbonate ion formation from CO2 as the rate-determining step. The mathematical models comprising coupled sets of non-linear differential and algebraic equations were solved using our software package for the absorber. The model was validated using plant data and was used to compute the flow, temperature and concentration profiles in the absorber for sensitivity analysis. The variation in exit CO2 concentration with respect to the operating conditions was also examined. (C) 2008 Elsevier B.V. All rights reserved.