Kinetics of CO2 Absorption in Aqueous Potassium L-prolinate Solutions at Elevated Total Pressure

AbstractAmino acid salts are promising absorptions for CO2 capture. This work investigated six common potassium amino acid solutions: L-proline, sarcosine, glycine, β- alanine, taurine, and L- threonine solutions using wetted-wall column at 313K and atmospheric pressure (1bar). We found potassium L-proline solution has significant mass transfer properties similar to 30 wt% MEA. The influence of total pressure in wetted-wall column on CO2 absorption rate in potassium L-prolinate solutions is determined. It is found that elevated total pressure has positive effect on CO2 absorption rate. The CO2 absorption flux increases approximately by 40% from 1bar to 3bar when CO2 inlet concentration is 10%. What's more, the gas side mass transfer coefficient is found not only dependent on the hydrodynamic conditions of wetted-wall column, but also the total pressure in the apparatus. The analytical relations between the hydrodynamic conditions of the column and kg in wetted-wall column at different pressures are got in this work, and the gas mass transfer coefficient kg is found decreases by 86% from 1bar to 3bar