Solubility estimations for Disperse Blue 14 in supercritical carbon dioxide

Supercritical carbon dioxide is an alternative solvent that is considered for dry dyeing processes in the textile industry. The application of this process requires a study to determine the dye solubility in supercritical carbon dioxide. The solubility in supercritical carbon dioxide of a disperse dye at temperatures of 40, 60 and 80 °C and pressures from 100 to 350 bar was evaluated in a previous study. In the work described here, these solubility values have been correlated with fairly good accuracy using a model based on thermodynamic aspects and the use of equations of state. Physical properties and critical parameters of the solid have been estimated using different group contribution methods. The thermodynamic model has been developed by means of a program based on fitting the solid sublimation pressure and binary interaction parameter. The results obtained in the solubility correlation show that the choice of group contribution method is more important than the choice of equation of state.