Phase equilibria of branched isomers of C10-alcohols and C10-alkanes in supercritical carbon dioxide

High pressure phase behaviour of the CO2+1-decanol+n-dodecane system

“…To enable the comparison between different systems interpolation of data is required. Interpolation has been used successfully in previous studies [4,16,17]. Polynomial correlations are fitted to the measured P-T data at each solute-solvent composition, after which interpolation between the measured data points is possible.…”

“…For comparison the three systems investigated in this work, as well as three systems investigated by Zamudio et al [4,6], namely CO2 + 1-decanol, CO2 + n-dodecane, and CO2 + (77.8 wt% 1-decanol + 22.2 wt% n-dodecane), are plotted in Figure 2 at T = 308 K and T = 348 K. It is noted that for the CO2 + 1-decanol system at solute mass fractions between 0.126 and 0.398 data were not measured at 308 K. The data presented at those mass fractions in Figure 2 (a) are extrapolated from measurements taken at around 313 K [4] and caution should be taken when comparing these data points to the other systems. From Figure 2 it is clear that there are definitely solute-solute interactions that need to be taken into account.…”

“…For the CO2 + Mixture C system the solubility pressures measured for a solute mass fraction of 0.183 at 308.0 K and 317.9 K are almost identical. This can be attributed to the temperature inversion present in the CO2 + 1-decanol system [4]. Given that a large fraction of Mixture C consists of 1-decanol it is expected that the temperature inversion, or indications thereof, would be present in the CO2 + Mixture C system in the mixture critical region.…”

“…The separation of close-boiling components is a concern in industry, since conventional distillation methods become uneconomical and alternative processing methods are required [2,3]. Amongst others, supercritical fluid fractionation (SFF) is considered for this separation problem, a process in which the unique properties of supercritical fluids are exploited to bring about the separation of compounds [3][4][5].…”

“…As a first approximation to the modelling of the separation of detergent range alkanes and alcohols Zamudio et al [4,6] considered the separation of 1-decanol and n-dodecane using supercritical CO2. The solubility of two binary systems, namely CO2 + 1-decanol and CO2 + n-dodecane, as considered in their investigation.…”