CO2+3,7-dimethyl-1-octanol+1-decanol: High pressure experimental phase equilibria data and thermodynamic modelling

摘要

New VLE data are presented for CO2 + 3,7-dimethyl-1-octanol (37DM1O) + 1-decanol (C10OH) at 35, 55 and 75 degrees C and pressures between 68 and 237 bar. Phase compositions were analysed using a static analytic apparatus with dual sampling and online chromatography. The mixture displays virtually no enhanced solubility, liquid curves remain convex throughout, and coexisting detached two-phase regions were not detected. CO2 can fractionate all measured 37DM1O:C10OH ratios though with limited efficacy, as highlighted by relative solubilities ranging from 1.1 to 1.5. RK-ASPEN, SR-POLAR, PR-BM and PC-SAFT correlations failed at 35 degrees C, the optimum fractionation temperature. At 55 and 75 degrees C, RK-ASPEN and SR-POLAR produced the smallest percentage average absolute deviations in equilibrium pressure of 4.0%, and RK-ASPEN was marginally superior at correlating vapour and liquid phase curves. At 35 degrees C and 187.5 bar, the 25:75 37DM1O:C10OH mixture passed through a density inversion and interesting images thereof are presented.