Membrane absorption using ionic liquid for pre-combustion CO2 capture at elevated pressure and temperature

- CO2 membrane absorption using ILs as absorbent at elevated temperature/pressure was studied.
- A tubular glass membrane with a hydrophobic surface was used in the membrane contactor.
- Selected absorbent [Bmim][TCM] shows high thermal stability and low viscosity.
- Various effects of the operating parameters on the separation performances were investigated.
- Kexp measured were compared with Kov estimated from the resistance in series model.

This study demonstrated the potential of applying ionic liquids as absorbents in membrane contactor for pre-combustion CO2 capture at elevated temperatures and pressures. Butyl-3-methlyimidazolium tricyanomethanide ([Bmim][TCM]) was used as a CO2 absorbent due to its high thermal stability, moderate viscosity and high CO2 absorption capacity. The effects of the operating parameters on the CO2 capture performance in a tubular glass membrane contactor were systematically investigated, including the operating temperature, pressure, and gas flow rate. An overall mass transfer coefficients (Kexp) value of 1.0 × 10−6 m s−1 and a CO2 flux of 2.50 × 10−4 mol m−2 s−1 were obtained at an operating temperature of 80 °C and pressure of 20 bar. The Kexp obtained from the experimental characterization were also compared with the Kov estimated from the resistance in series model.

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