Glycol Loss in a Gaseous System: Thermodynamic Assessment Test of Experimental Solubility Data
Résumé
Triethylene glycol (TEG) is generally used to adjust the water dew point in natural gas processes. Unfortunately, only very few sets of experimental data regarding solubilities of these humidity absorbents in supercritical natural gas components have been reported in the literature partly due to the difficulties in such very low concentration measurements. Therefore, a satisfactory accuracy of measurements is not obvious, and the reliability of the corresponding data must be checked prior to their application. In this study, we focus on presenting the results of a thermodynamic assessment test (consistency test) for experimental solubility data of triethylene glycol in supercritical methane and carbon dioxide. The Gibbs Duhem equation in terms of pressure, fugacity coefficients, solubilities of triethylene glycol in gas phase, and compressibility factor of gas phase is applied for the consistency test. The Soave-Redlich-Kwong (SRK) equation of state (EoS) along with the van der Waals (vdW2) mixing rules is used to represent the corresponding solubilities. The results show that three sets of the four investigated experimental data sets are thermodynamically consistent, while one data set is not fully consistent.