LAUSR

Abstract Absorption and desorption of CO2 using K2CO3 solutions promoted by three amino acid salts (AASs), potassium glycinate (PG), potassium lysinate (PL) and potassium L-argininate (PA), were evaluated using 40% CO2 at 40 °C and with pure N2 at 80 °C, respectively. The addition of all 3 AASs clearly enhanced both absorption and desorption of CO2 compared to single K2CO3 solution. PA + K2CO3 solution showed the highest CO2 cyclic capacity of 0.678 mol CO2/mol absorbent, while the highest CO2 absorption and desorption rates of 39.8 and 17.6 mol CO2 L−1 s−1 were achieved by PG + K2CO3 solution. Finally, simulated biogas containing 40% of CO2 and 60% of CH4 was used as test gas in a hollow fiber membrane contactor. PG and PA promoters presented higher CO2 absorption flux and removal efficiency than PL promoters in K2CO3 solution within low Gas/Liquid ratio region. Stable CO2 removal performances for all three promoters were observed at elevated temperature and pressure for 60 min operation.