Selection and characterization of phase-change solvent for carbon dioxide capture: precipitating system

Characterization of a precipitating solvent for CO₂ capture was performed. Aqueous solution of 5m’ potassium salt of sarcosine (KSar) that was precipitated at CO₂ loading of 0.52 was selected. The equilibrium solubility of CO₂ in the solution was measured over a range of temperatures from 40 to 120 °C. The SOFT model was implemented to predict the vapor-liquid-solid equilibrium (VLSE) data for the CO₂-KSar-H₂O system. The vapor pressures of the solution were measured at temperatures between 53 and 130 °C. The heat of absorption was also measured at 40 °C. In addition, the heat of absorption of CO₂ in the solution was estimated from the VLSE data by use of the Gibbs- Helmholtz equation and was able to predict well the precipitation occurred in the system.