A novel nonaqueous solution, triethylenetetramine (TETA) blended with polyethylene glycol (PEG200), was developed for CO2 absorption, with which a phase-changing phenomenon was observed after the absorption. A reaction mechanism for TETA PEG200 solution and CO2 was proposed based on C-13 NMR analysis. It was found that PEG200 not only acts as a solvent that contributes to biphasic separation but also gets involved in the reactions, leading to an increased CO2 absorption capacity. Results show that 1 M TETA PEG200 solution exhibits a high CO2 capacity of 1.63 mol/mol TETA, which is comparable to a TETA-water solution. The capacity is only slightly affected when the temperature rises up to 60 degrees C. Moreover, the solution demonstrates good thermostability similar to typical functionalized ionic liquids (ILs) while presenting much lower viscosity than the ILs. For regeneration processes, microwave heating was identified to be a more effective method than classic heating. The solution shows a regeneration efficiency as high as 96% after four absorption-desorption cycles.