CO2 Capture by Alkaline Solution for Carbonate Production: A Comparison between a Packed Column and a Membrane Contactor

Abstract

A comparison between a traditional packed column and a novel membrane contactor used for CO2 absorption with carbonate production is addressed in this paper. Membrane technology is generally characterized by a lower energy consumption, it offers an independent control of gas and liquid streams, a known interfacial area and avoids solvent dragging. Those advantages make it a potential substitute of conventional absorption towers. The effect of the concentration and the flow rates of both the flue gas (10–15% of CO2) and the alkaline sorbent (NaOH, NaOH/Na2CO3) on the variation of the species present in the system, the mass transfer coefficient, and the CO2 removal efficiency was evaluated. Under the studied operation conditions, the membrane contactor showed very competitive results with the conventional absorption column, even though the highest mass transfer coefficient was found in the latter technology. In addition, the membrane contactor offers an intensification factor higher than five due to its compactness and modular character.

Keywords

• CO2 capture
• membrane contactor
• packed column
• intensification