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

One of the efficient methods for reducing CO2 emissions from flue gas streams in oil refineries and power plants is the CO2absorption process using alkali solution. Potassium carbonate (K2CO3) solution, as CO2 absorbent, was used in the present study due to its high CO2 absorption capacity. However, K2CO3 has a drawback which is represented by its slow reaction with CO2. To overcome this issue, an oscillatory baffled column (OBC) was utilized as a contactor to maintain a high degree of mixing in the CO2 absorption system and thereby increasing the reaction rate between K2CO3 and CO2 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) CO2 balanced with N2) and oscillation conditions on CO2 absorption in a semi-batch OBC were investigated. The experiments were performed with range of modified Reynolds Number of Oscillation (Reo′ = 0⎼1450) and aeration rates (0⎼1 vvm) using K2CO3 (100 g/L, 0.72 M)0.1.8–3.5-fold of enhancement of CO2 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 CO2 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 CO2 removal processes.