CO2 Solubility in Physicochemical Absorbent: Dibutyl Ether/N-Methylethanolamine/Ethanol

In this work, a physicochemical absorbent was proposed for CO2 capture, which consists of dibutyl ether as physical solvent, N-methylethanolamine (NMEA) as chemical additive, and ethanol as dissolvent. The vapor–liquid equilibrium behavior of this CO2 + physicochemical absorbent system was measured using an isothermal synthetic apparatus. The solubility data of CO2 in ethanol at 313.15 K were measured and compared with literature data to verify the validity of this method. Then, the CO2 solubility data of above system with varying NMEA mass fractions of 15 %, 25 %, and 50 % were, respectively, measured at 298.15 K. It shows that the CO2 solubility increases when NMEA mass fraction goes up. The CO2 solubility data in the absorbent with 25 % NMEA mass fraction were measured at a temperature range from 298.15 K to 328.15 K with the interval of 10 K and at a pressure range from 0 MPa to 3 MPa. The result shows that CO2 turns out to be more soluble in the physicochemical absorbents than in dibutyl ether at the same conditions of temperature and pressure.