Consistency test of solubility data of ammonia in ionic liquids using the modified Peng-Robinson equation of Kwak and Mansoori

Phase equilibrium data of temperature, pressure and solubility (T-P-x) of ammonia in different types of ionic liquids over wide ranges of temperatures and pressures are modeled and tested for thermodynamic consistency. The modified Peng-Robinson equation of state proposed by Kwak and Mansoori is used for correlating the isothermal PX data and a flexible thermodynamic consistency method applied to analyze forty seven isothermal P-x data available in the open literature. Modeling is found acceptable in all cases, meaning that deviations in correlating the data are low, proving at the same time the claimed flexibility of a well-founded model that uses simple van der Waals mixing rules. For all cases, the thermodynamic consistency method gives a clear conclusion about consistency or inconsistency of a set of experimental T-P-x data based on the established criteria. (C) 2013 Elsevier B.V. All rights reserved.