Ternary Diffusion Coefficients of Monoethanolamine and Triethanolamine in Aqueous Solutions Containing Monoethanolamine and Triethanolamine

Abstract

Ternary diffusion coefficients of monoethanolamine (MEA) and triethanolamine (TEA) in aqueous solutions containing MEA and TEA using the Taylor dispersion technique have been measured for temperatures 303.2, 308.2, and 313.2 K. The systems studied were aqueous solutions containing total amine concentrations of 2.0 and 3.0 kmol·m^–3, each having three different amine-molar ratios. The density and viscosity of the blended amine solutions were also measured. The mutual diffusion coefficients of aqueous MEA and aqueous TEA solutions were also reported. The main diffusion coefficients (D₁₁ and D₂₂) and the cross diffusion coefficients (D₁₂ and D₂₁) were reported as function of temperature and concentration of alkanolamines. The limiting conditions for the main diffusion coefficients and the cross diffusion coefficients were discussed at first, and a comparison between the ratios of the cross diffusion coefficients to the main diffusion coefficients for MEA and TEA was made. Finally, the dependence of the main diffusion coefficient D_ik on the viscosity of solutions was investigated.