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

Abstract

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.

Solubility of CO2 in Nonaqueous Absorption System of 2-(2-Aminoethylamine)ethanol + Benzyl Alcohol

“…9−12 On the other hand, the aqueous amine solution processes usually suffer from fast equipment corrosion and amine degradation at high temperature. 9 In brief, the disadvantages of the conventional CO 2 capture processes with aqueous amine solutions are commonly ascribed to water. If water is substituted by other high-boilingpoint solvents, a considerable amount of thermal energy can be saved during the solvent heating cycle, 9,13 and the corrosion will also be eliminated.…”

Beton‐ und Stahlbetonbau aktuell 10/2014

“…In subsequent regeneration cycles, the aqueous phase loses efficiency due to solvent degradation. This performance is commonly observed in aqueous solutions of amines 28 used for CO 2 absorption during solvent regeneration by stripping. Hence, the CO 2 absorption cycle reduces its efficiency as a result of the loss of MDEA concentration in the solvent due to an incomplete regeneration.…”

Carbon dioxide chemical absorption by solvents based on diamine and amines blend

“…This variable tends to decrease mass transfer rate by different causes. On one hand, an increase in viscosity causes an increase in mass transfer resistance throughout the gas-liquid interface, 10,11 and conversely, this property produces an increase in bubble size diameter (when bubbling reactors are used) that causes also a decrease in gas-liquid interfacial area. [12][13][14] Both effect have negative influence upon carbon dioxide absorption rate.…”