Experimental Study of Density, Viscosity and Equilibrium Carbon Dioxide Solubility in Some Aqueous Alkanolamine Solutions

Abstract

In this work, equilibrium solubility of CO2 in aqueous blends of different amines is examined. The amines used are methyldiethanolamine (MDEA), N,N-dimethylaminoethanol (DMAE), N,N-diethylaminoethanol (DEAE), 2-(2-aminoethylamino)ethanol (AEEA), and 3-methylamino propylamine (MAPA). New equilibrium solubility data for CO2 in aqueous solutions of DMAE + MAPA, DMAE + AEEA, MDEA + MAPA, MDEA + AEEA, DEAE + MAPA and DEAE + AEEA over a range of low pressures are obtained. Each of the solutions contains 40 wt% of a tertiary amine (DMAE, MDEA, DEAE) and 5 wt% of a primary/secondary amine (MAPA, AEEA). The experimental temperature was set to 313.15 K and the measured CO2 loading was in the range of 0.274–4.563 (mol CO2 per kg of solution). In order to make a better comparison, viscosities and densities of the amine solutions were also measured at 303.15–353.15 K. Experiments show that the aqueous DMAE + MAPA blend has the highest absorption capacity, and at the same time, its viscosity and density are in a desirable range.