Dynamics of CO₂ Absorption and Desorption Processes in Alkanolamine with Cosolvent Polyethylene Glycol

To reduce the high energy consumption and equipment corrosion in conventional processes of CO 2 capture with aqueous amine solutions, the mixed nonaqueous solvents of monoethanolamine (MEA), diethanolamine (DEA), and diglycolamine (DGA) with polyethylene glycol (PEG) as cosolvent were explored for CO 2 capture. The dynamic experiments of CO 2 absorption and desorption were carried out to evaluate the performance of the studied nonaqueous solutions. It demonstrated that the mixed solutions of amines and PEG exhibited higher CO 2 cyclic capacity and regeneration efficiency compared with the only aqueous amine solutions. Especially, the solution of 3 mol/L DGA-PEG200 exhibits a high cyclic capacity of 0.438 mol CO 2 /mol DGA and a high regeneration efficiency of 94.6%, which indicates its great potential in industrial application. Moreover, the very low vapor pressure of PEG helps the mixed solution for CO 2 capture with reduced corrosion, energy consumption, and environmental pollution.