Molecular simulation of the salting out effect in the system H2S–H2O–NaCl

Abstract

The reduction of the solubility of a gas due to the presence of ionic species in a solvent is called “salting-out”. The “salting-out” of hydrogen sulfide by sodium chloride in water was predicted by Gibbs ensemble Monte Carlo simulation at temperatures between 373 and 423 K and at salt molalities up to 10 mol kg⁻¹.

The intermolecular interactions were modeled by combining Lennard-Jones potentials with Coulomb interactions. Several force fields were examined. The interactions between unlike species were estimated using two common combining rules without any adjustable parameters for the dispersion interaction. The simulations predict the “salting-out” of hydrogen sulfide by sodium chloride in aqueous solutions in an at least qualitative, partly in a quantitative manner.