Diffusion Coefficients and Viscosities of CO₂ + H₂O, CO₂ + CH₃OH, NH₃ + H₂O, and NH₃ + CH₃OH Liquid Mixtures

Abstract

To evaluate quantitatively the results of gas−liquid absorption experiments, accurate liquid-phase diffusion coefficients and viscosities are needed. In this paper experimental values of these quantities will be reported for the binary systems carbon dioxide + water, carbon dioxide + methanol, ammonia + water, and ammonia + methanol. The diffusion coefficients have been measured using the Taylor−Aris dispersion method, and the viscosities have been measured with a falling ball viscometer at temperatures from 293 to 333 K. The ammonia mole fraction ranged from 0 to 0.312. The results have been correlated using Arrhenius-type equations and have been compared with literature data, where available. Furthermore, the measured diffusion coefficients are compared with values predicted by the modified Stokes−Einstein equation and the Wilke−Chang equation.