Raman spectroscopic study on the equilibrium of carbon dioxide in aqueous monoethanolamine

Abstract

Aqueous phase characterization and thermodynamic modeling of the vapor liquid equilibrium of CO₂ in a reactive solvent are important for designing and operating CO₂ removal systems. A quantitative method using Raman spectroscopy was applied to determine the absorption capacity and molality of various ionic and molecular species in liquid phase CO₂ loaded monoethanolamine (MEA) solutions. Species distribution profiles during absorption were reported for a wide range of CO₂ loading. CO₂ solubility in aqueous MEA with concentrations varied from 10 to 30 mass% were studied using in situ Raman spectroscopic analysis for pressure ranges from 1 to 50 bar at 303.15, 313.15 and 323.15 K. Vapor liquid equilibrium data for the CO₂–MEA–water ternary system was analyzed using the Deshmukh–Mather model.