Correlating bubble points of ternary systems involving nine solventsand two ionic liquids using artificial neural network

use of ionic liquids is being increasingly investigated in separation technologies, for example, in spe-cial distillation processes such as azeotropic or close-boiling mixtures. Such applications require accurateknowledge of the physical properties of the mixtures involved. In this respect, the correlation or esti-mation of the bubble points might be difficult due to the complex nature of some ternary systems,especially in the presence of ionic liquids. In the present study, the bubble points of several ternary mix-tures containing an ionic liquid were correlated using an artificial neural network modeling approach.The solvents investigated consisted of 1-propanol, 2-propanol, ethyl ethanoate, methyl ethanoate,chloroform, propanone, ethanol, methanol and water and the ionic liquids considered were 1-ethyl-3-methylimidazolium trifluoromethane-sulfonate ([emim][CF3SO3]) and 1-butyl-3-methylimidazoliumtetrafluoroborate ([bmim][BF4]). For this purpose, a total of 529 experimental data points from previ-ously published literature were collected to aid in finding the best network architecture and the optimumparameters. To do this, the collected data were divided into two subsets, namely the training and test-ing subsets. Using the training data set, and based on a trial and error procedure, the optimum networkparameters were determined to be three layers including one input, one hidden and one output layer,nine neurons in the hidden layer, the logarithmic-sigmoid transfer function for the hidden layer, and thepurline function for the output layer. The optimized weights and biases were also obtained and presented.The feasibility of the proposed network for the correlation of ternary bubble point was then examinedusing data that were not used in optimizing the network. The overall average absolute relative deviation(AARD %), mean square error (MSE), maximum deviation (Emax), minimum deviation (Emin) and correlationcoefficient (R2) were calculated to be 0.20%, 0.9953, −0.97, 0.87 and 0.95, respectiv

1-Ethyl-3-methylimidazoliumtrifluoromethane-sulfonate([emim][CF3SO3])1-butyl-3-methylimidazoliumtetrafluoroborate([bmim][BF4])Ionic liquidsPhysical propertya