Measurement of the critical temperatures, pressures, and thermal diffusivities of glymes from monoglyme to tetraglyme

Abstract

The critical temperatures, critical pressures, and thermal diffusivities have been measured for mono-, di-, tri-, and tetraglymes, compounds that are used for pre- and post-combustion capture of CO2, H2S and other gases. The critical properties have been measured using the pulse-heating method applicable to thermally unstable compounds. The combined relative expanded uncertainties with the 0.95 level of confidence are 0.01 and 0.03 for the critical temperature and pressure, respectively. The acentric factors of the compounds have been calculated based on the experimental data. The critical properties of these compounds have also been calculated by the group contribution methods of Wilson and Jasperson, Nannoolal et al., and Hukkerikar et al. in two variants. The Wilson/Jasperson technique provides the best estimation of the critical temperature and the Hukkerikar et al. one gives the best results for the critical pressure. The thermal diffusivities of glymes have been measured at atmospheric pressure in the temperature range from 303.15 to 353.15 K. The thermal conductivities of glymes have been calculated from the experimental data. The temperature dependence of the thermal diffusivities and thermal conductivities has been approximated by linear polynomials. The experimental thermal conductivities of glymes have been compared with those estimated by the methods of Govender et al. and Liu et al. The method of Govender et al. provides a good estimation of the thermal conductivity of glymes.