Liquid-liquid phase change absorbents,as the most energy-saving potential,emerging absorbents in the field of carbon capture,still suffer from the disadvantages of limited CO2 capacity and high corrosiveness.Ionic liquids are synthesized by using amino-rich polyamide-amine dendrimer(PAMAM)as the cation and 2-methylimidazole(2-MI)with an N-heterocyclic ring as the anion,and used together with water and diethylene glycol butyl ether(DGBE)to construct liquid-liquid phase change absorbent.The multiple amines synergistic absorption mode helps the absorbent to improve its performance greatly in absorbing CO2.The absorbent's CO2 capacity reaches 4.98 mol CO2/mol Ils,the CO2-rich phase volume shares only 28.7%,and the corrosivity is only 13.87%that of monoethanolamine solution.It is demonstrated by13 C NMR analysis result that the absorption mechanism follows the zwitterionic mechanism and a base-catalyzed hydration mechanism.It is found from quantifying polarity by Kamlet-Taft method that the generation of phase separation phenomena is closely related to changes in polarity,density,and viscosity.
关键词
CO2捕集/功能化离子液体/相变吸收剂/吸收机理/相变机理
Key words
CO2 capture/functionalized ionic liquid/phase change absorbent/absorption mechanism/phase change mechanism
万方数据