Experimental study and thermodynamic model for respective solubilities of CO2 and ethanol for CO2-ethanol-polystyrene ternary system at elevated pressure and temperature

摘要

Foamed non-Fickian diffusion (FNFD) model for a ternary system was proposed for the first time to regress the desorption data obtained by the gravimetric method. Results showed that FNFD model could accurately describe the diffusion behavior of CO2 and ethanol out of foamed polystyrene (PS) and well predict total solubilities of CO2 and ethanol in foamed PS. Meanwhile, Sanchez-Lacombe equation of state (S-L EoS) was adopted to calculate the respective solubilities (solubility of CO2 in PS or solubility of ethanol in PS) and total solubilities of CO2 and ethanol in PS for CO2-ethanol-PS ternary system. Results showed that the total solubility of CO2 and ethanol obtained from S-L EoS agreed well with values obtained by FNFD model. Furthermore, the respective and total solubilities of CO2 and ethanol at 313.15, 338.15, and 343.15 K were calculated by S-L EoS. Results indicated that in the dissolving process, ethanol would be accelerated by CO2 to dissolve into PS, and ethanol would compete with CO2 to dissolve into PS, simultaneously. (c) 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46281.