Comparative study: Absorption enthalpy of carbon dioxide into aqueous diisopropanolamine and monoethanolamine solutions and densities of the carbonated amine solutions

• Absorption enthalpy of CO2 in monoethanolamine–water and diisopropanolamine–water solutions with amine mass fraction 0.1–0.2 for MEA and 0.1–0.3 for DIPA.
• Density of the carbonated MEA and DIPA solutions up to loadings of 1 mol CO2 (mol amine)−1.
• Experimental density data correlated with Weiland density equations.
• Absorption enthalpy data correlated with partial reaction enthalpies together with electrolyte NRTL.

Absorption processes using aqueous alkanolamines are under intense research for new gas purification and carbon capture applications. In this work continuous flow calorimetry (SETARAM C80) and vibrating tube densimetry were used to measure absorption enthalpies of carbon dioxide (CO2) into aqueous amine solutions and the final densities of carbonated amine solutions. We present new data for monoethanolamine (MEA) and diisopropanolamine (DIPA) solutions of 0.1–0.2 mass fraction MEA and 0.1–0.3 mass fraction DIPA. CO2 loadings used in the study were 0–1.0 mol CO2/mol amine. New experimental data presented herein will facilitate the validation and/or further development of thermodynamic models describing the absorption phenomena.