Vapor pressure osmometry of 1-butyl-3-methyl imidazolium thiocyanate in aqueous solution and its prediction by PC-SAFT

The separation of benzene and thiophene from petroleum products is one of the most important gasoline production processes in the oil industry. Imidazole and thiocyanate-based ionic liquids have been used effectively to separate benzene and thiophene. This is despite the fact that basic studies, on the other hand, remain important for the identification of this type of ionic fluid. The osmotic coefficient is the most important quantity for the electrolyte system that can be used to describe the behavior and study the interactions that occur in the systems. Therefore, the behavior of ionic liquids as electrolytes is also of special importance because these materials are highly hydrophilic, and this may change the design conditions of the process. Therefore, in thisstudy, the osmotic coefficient of the aqueous solution of ionic liquid 1-butyl-3-methylimidazolium thiocyanate (IL) in the temperature range (298.15 - 328.15) K was measured by steam pressure osmometry up to 1 mol kg-1. Water activity and water vapor pressure reduction are determined. The developed Pitzer-Archer model was used to correlate the experimental osmotic coefficient and obtain the mean IL activity coefficient. The average standard deviation for osmotic coefficient values in the binary system with the Pitzer-Archer model is 0.012. The PC-SAFT and PCP-SAFT equations were also used to predict the osmotic coefficient.