Salt solubility modeling in mixed solvents with a modified Pitzer approach: Application in water + MEG + electrolyte systems

Monoethylene glycol (MEG) has been applied as an inhibitor of hydrate formation in natural gas exploitation. The recovery unit of MEG presents salt scale issues that promote operational problems. A literature survey and analysis of salt solubility data in water–MEG mixtures have been performed, revealing that experimental studies are available for eight electrolyte species (NaCl, NaHCO3, KCl, Na2SO4, KI, KBr, K2SO4, and CaSO4), in total 616 data points. This work aimed at the development of a calculation methodology using Pitzer–Lorimer approach for salt solubility in mixed solvents. Python language was properly used to design the computational tool, which is freely available. The results demonstrated the feasibility of the salt solubility description in mixed solvents, and relative deviations less than 5% were obtained for the eight studied salts. Furthermore, the developed tool can be easily applied for parameter estimation and salt solubility prediction of other electrolyte systems.