Enhancement of CO2 removal from flue gas in an oscillatory baffled column using potassium carbonate solution

One of the efficient methods for reducing CO 2 emissions from flue gas streams in oil refineries and power plants is the CO 2 absorption process using alkali solution. Potassium carbonate (K 2 CO 3 ) solution, as CO 2 absorbent, was used in the present study due to its high CO 2 absorption capacity. However, K 2 CO 3 has a drawback which is represented by its slow reaction with CO 2 . To overcome this issue, an oscillatory baffled column (OBC) was utilized as a contactor to maintain a high degree of mixing in the CO 2 absorption system and thereby increasing the reaction rate between K 2 CO 3 and CO 2 as well as enhancing the mass transfer rate. In this study the effect of different operation conditions of the process namely; inlet flue gas flow rate (15 % (v/v) CO 2 balanced with N 2 ) and oscillation conditions on CO 2 absorption in a semi-batch OBC were investigated. The experiments were performed with range of modified Reynolds Number of Oscillation ( R e o ′ = 0⎼1450) and aeration rates (0⎼1 vvm ) using K 2 CO 3 (100 g/L, 0.72 M)0.1.8–3.5-fold of enhancement of CO 2 absorption rates was achieved by using OBC with respect to that obtained by baffled column (BC) (only baffles without oscillation) and plane bubble column (PBC) (without baffles and oscillation), respectively. The use of K₂CO₃ as a solvent in an oscillating reactor (OBR) to remove CO₂ represents a new method due to the high reactivity of K₂CO₃ with CO₂, forming stable bicarbonate and carbonate compounds. OBR's enhanced mixing capabilities improve mass transfer rates and reaction efficiency, allowing for more effective CO 2 capture compared to conventional reactors. This combination leverages the strengths of both the chemical reactivity of K₂CO₃ and the mechanical benefits of OBR, potentially leading to more efficient and scalable CO 2 removal processes.