Solubilities of Ammonia in Polyethylene Glycols at 298.2–353.2 K and 0–200 kPa

Polyethylene glycols (PEGs) are potential solvents for NH₃ capture, considering that they have abundant hydroxyl groups, which can form hydrogen-bond interaction with NH₃. To this end, the solubilities of NH₃ in PEGs with average molecular weights of 100–600 g·mol^–1 were measured at 298.2–353.2 K and 0–200 kPa in the present work. It is found that the solubilities of NH₃ increase linearly with the increase of pressures, but decrease with the increase of temperatures. In addition, the solubilities of NH₃ show negative dependence on the molecular weights of PEGs, because PEGs with higher molecular weights exhibit lower hydroxyl densities. The Henry’s constants and enthalpy changes for NH₃ absorption in PEGs were also calculated based on the variations of NH₃ solubilities with pressures and temperatures. Furthermore, the physical properties of PEGs that are essential for NH₃ absorption such as densities and surface tensions were also measured at 293.2–353.2 K in the present work.