Amino Acid Salts for Carbon Dioxide Capture: Evaluating l‑Prolinate at Desorber Conditions

Vapor–liquid equilibrium (VLE) measurements for unloaded and CO₂-saturated aqueous potassium salt solutions of l-proline have been performed using a high-pressure equilibrium cell. The solubility of CO₂ has been determined at temperatures of 363, 393, and 403 K in 3 and 4 mol dm^–3 aqueous solutions. The CO₂ partial pressures ranged from 3.0 to 358 kPa. In addition, the VLE data for CO₂-free and CO₂-saturated 3 mol dm^–3 aqueous potassium sarcosinate solutions are presented for the same range of temperatures. The vapor pressures of the considered compounds have been determined at temperatures from 353 to 403 K. The reboiler duty required for stripping CO₂ from potassium l-prolinate solutions has been computed by the summation of the desorption enthalpy of CO₂, sensible heat, and evaporation heat associated with co-produced regenerator overhead water vapor. A new approach to calculate the latter contribution is presented. The calculated energy requirements for l-prolinate are in the range reported in the literature for other amino acid salts