Investigation and prediction of the salting-out effect of methane in various aqueous electrolyte solutions

The maximum solubility of methane was determined in aqueous solution of Al-2(SO4)(3), MgSO4, K2SO4, Na2SO4, AlCl3, MgCl2, KCl, NaCl, MgBr2, KBr, and NaBr with various concentration (1, 3 and 5 wt%) at ambient pressure. Salting-out effect was observed in all electrolyte solutions, exhibiting lower solubility of methane compared to that in pure water. In general, electrolyte solutions comprising cations/anions with high charge valency and small ionic radius exhibited stronger salting-out effect due to large charge density of the corresponding ions. Furthermore, anions exhibited larger influence on the degree of salting-out compared to cations. Scaled particle theory was employed to corroborate the trend of the experimental solubility of methane in electrolyte solutions. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.