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

Abstract

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, NaHCO 3 , KCl, Na 2 SO 4 , KI, KBr, K 2 SO 4 , and CaSO 4 ), 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.

New Process for Na2CO3 Production from Na2SO4 Based on Modeling the Na2SO4–(NH4)2SO4–MEA–MEG–H2O System

“…Neerup et al determined the solubility of ice and urea in two systems: urea–MEA–H 2 O and MEG–MEA–H 2 O for the improvement of thermodynamic modeling of new CO 2 solvents. The Pitzer–Lorimer approach was recently used to correlate eight salts’ solubility data in water–MEG mixtures with adequate results. The mixed-solvent electrolyte (MSE) model , developed by OLI Systems was used to successfully model phase equilibria for the mixed MEG electrolyte systems, which contain various salts and dissolved gases.…”