A new model and estimation of thermodynamic parameters for the solubility of azobenzene and anthraquinone derivatives in supercritical carbon dioxide

Proper measurement and correlation/prediction of solubility data of dye compounds (azobenzene and anthraquinone derivatives) in supercritical carbon dioxide -(ScCO2) are essential in the development supercritical dyeing technology. Ample data are available for several dye compounds in the literature, but models that are satisfactorily correlating/predicting solubility data are rare. Therefore, in this study, a simple model is developed for the solubility (y(2)) in terms of reduced temperature (T-r) and reduced density (rho(r)) to correlate industrially important dye compounds solubility in -ScCO2. The proposed model is y(2) = A + (B + C rho(r))T-r + (D + E rho(r))rho(r) T-r(2) + F rho T-2(r)r(3). The performance ability of the new model is compared with number of existing literature solubility models in terms of various statistical parameters of (AARD, R-2, Adj. R-2, SSE, and RMSE) as well as Akaike's Information Criterion (AIC). Moreover, thermodynamic parameters such as sublimation pressure (P-sub), sublimation enthalpy (Delta H (sub)) and enthalpy of solvation (Delta H-sol) were estimated for anthraquinone and azobenzene derivatives. It was found the proposed model is correlating better than existing models.