Thermofluidic characteristics for a novel complementary adsorption-absorption post-combustion partial CO₂ capture system

A novel complementary adsorption-absorption post-combustion partial CO₂ capture strategy was proposed to decrease the energy penalty by integrating the rotary adsorption wheel with traditional chemical absorption process. The finite volume method is used for modeling the adsorption process, and the absorption process is simulated based on the rate-based model and the double-film theory. The techno-economic analyses of the novel complementary system were performed. In the adsorption part, the CO₂ concentration of the flue gas can be effectively improved from 5.0%, 10.0% and 15.0% as much as to 17.3%, 27.0% and 33.7%, respectively. By adjusting the flue gas ducts of the adsorption wheel, the flue gas can be concentrated to a CO₂ concentration making the absorption process work economically. The performance of the rotary adsorption wheel influenced by different geometrical and operational parameters were investigated. The energy penalty of the chemical absorption part can be significantly decreased. The major equipment cost was dramatically decreased by 48.6%, and the levelized cost of CO₂ capture was decreased by 32.3%, when the CO₂ concentration in the flue gas was increased from 5% to 20%. In addition, the acceptable investment of the rotary adsorption wheel has been estimated. The smallest acceptable capital cost of rotary adsorption wheel for coal-fired boiler corresponding to one payback year is 3.72 M$.