Experimental measurement and modelling with Aspen Plus® of the phase behaviour of supercritical CO2 + (n-dodecane+1-decanol+3,7-dimethyl-1-octanol)

Experimental phase equilibrium data for the systems CO2 + n-dodecane, CO2 + 1-decanol and CO2 + 3,7-dimethyl-1-octanol were used to determine values for binary interaction parameters for use in the RK-ASPEN thermodynamic model in Aspen Plus (R). Bubble and dew point data of the mixtures CO2 + (n-dodecane + 1-decanol), CO2 + (n-dodecane + 3,7-dimethyl-1-octanol), CO2 + (1-decanol + 3,7-dimethyl-1-octanol) and CO2 + (n-dodecane + 1-decanol + 3,7-dimethyl-1-octanol) were measured experimentally in a static synthetic view cell, and compared to the data predicted by the RK-ASPEN model. The model predicted the phase equilibrium data reasonably well in the low solute concentration region; significant deviation of model predictions from experimental data occurred in the mixture critical and high solute concentration regions due to the exclusion of solute-solute interaction parameters in the model. Distribution coefficients and separation factors were determined for the multicomponent mixture and separation of the alkane from the alcohol mixture with a supercritical fluid extraction process was found to be possible. (C) 2013 Elsevier B.V. All rights reserved.