Non-Aqueous CO₂ Capture at Elevated Pressure: A Preliminary Investigation of 2 Methylaminoethanol/Morpholine/Sulfolane Mixtures

Carbon dioxide (CO2) absorption in a non-aqueous solution is a potential technology for reducing greenhouse gas emissions. In this study, a non-aqueous solvent, sulfolane was blended with 2-(methylamino)ethanol (2-MAE) and morpholine (MOR). The non-aqueous blended amines absorbents’ CO2 absorption ability was investigated in a high-pressure absorption reactor with a variable absorption pressure (350–1400 kPa) at constant temperature (303.15K). It was also found that the CO2 solubility increased with increasing pressure and amines total concentration. Subsequently, CO2 absorption rate further increases with the increased of MOR concentration. The highest CO2 solubility and CO2 absorption rate were observed in 2M 2-MAE + 2M MOR in sulfolane solution was observed at a pressure of 1400 kPa at 303.15 K with 1.2507 mmolCO2/kg and 25.15 mmol/min at 340 kPa . The use of non-aqueous blended amine solvents showed no phase separation phenomenon after the CO2 absorption reaction and the formation of carbamate salt was identified through density, vecosity, conductivity and FTIR analysis. This suggest that the use of a 2-MEA/MOR in sulfolane non-aqueous mixture solvent could be a promising solution for CO2 capture.