Dehydration
of natural gas (NG) by absorption is a common industrial
procedure implemented in order to avoid flow blockage and equipment
breakdown. Despite the widespread use of dehydration units, few experimental
data are available in the literature and most engineering practices
are based on empirical correlations for the design and the determination
of the optimum operational parameters. In this paper, an accurate
thermodynamic model for NG mixtures, the UMR-PRU, is further extended
to mixtures containing triethylene glycol (TEG) and is then used to
simulate a typical NG dehydration unit using TEG by incorporating
it in commercial simulators through the CAPE-OPEN standard. The results
are compared with those obtained by the recommended by Aspen Hysys,
TST/NRTL model. The two models calculate similar lean TEG purity,
TEG circulation rate, and stripping gas rate in order to obtain the
same level of dehydration, ca. 30 ppm water in the dry gas, while
some differences are observed in the component distribution in the
vapor and liquid phases. In addition, different reboiler duties are
calculated by the two models, with those of UMR-PRU to be considered
more realistic due to better prediction of the heat capacities of
aqueous TEG mixtures.