TY - JOUR
T1 - Aliphatic + ethanol separation via liquid-liquid extraction using low transition temperature mixtures as extracting agents
AU - Rodriguez, N.
AU - Santacruz Molina, B.
AU - Kroon, M.C.
PY - 2015
Y1 - 2015
N2 - In this work, two different low transition temperature mixtures (LTTMs), e.g., (i) glycolic acid–choline chloride molar ratio = (1:1) (GC(1:1)) and (ii) lactic acid–choline chloride molar ratio = (2:1) (LC(2:1)), were evaluated as potential extracting agents for the separation of the azeotropic mixtures {hexane + ethanol} and {heptane + ethanol}. Firstly, the liquid–liquid equilibrium (LLE) data of the ternary systems {hexane + ethanol + LTTM} and {heptane + ethanol + LTTM} were experimentally determined at T/K = 298.15 and T/K = 308.15. Secondly, the solute distribution coefficient and selectivity were calculated and analyzed. The influence of the temperature on the phase behavior and the performance of the LTTMs related to the chain length of the hydrocarbon were considered. A literature comparison with other extracting agents used for the separation of these mixtures was performed in order to evaluate the suitability of the studied LTTMs. Moreover, the recyclability of the extraction agent, which is of great importance in liquid–liquid extraction, was demonstrated. Finally, the experimental data were successfully fitted using the NRTL model. It was found that both LTTMs show a competitive performance compared to existing extracting agents. It was also established that both in the {hexane + ethanol} and {heptane + ethanol} separation, the LC(2:1) showed higher distribution coefficient than the GC(1:1), while the opposite trend was found for the selectivity values.
AB - In this work, two different low transition temperature mixtures (LTTMs), e.g., (i) glycolic acid–choline chloride molar ratio = (1:1) (GC(1:1)) and (ii) lactic acid–choline chloride molar ratio = (2:1) (LC(2:1)), were evaluated as potential extracting agents for the separation of the azeotropic mixtures {hexane + ethanol} and {heptane + ethanol}. Firstly, the liquid–liquid equilibrium (LLE) data of the ternary systems {hexane + ethanol + LTTM} and {heptane + ethanol + LTTM} were experimentally determined at T/K = 298.15 and T/K = 308.15. Secondly, the solute distribution coefficient and selectivity were calculated and analyzed. The influence of the temperature on the phase behavior and the performance of the LTTMs related to the chain length of the hydrocarbon were considered. A literature comparison with other extracting agents used for the separation of these mixtures was performed in order to evaluate the suitability of the studied LTTMs. Moreover, the recyclability of the extraction agent, which is of great importance in liquid–liquid extraction, was demonstrated. Finally, the experimental data were successfully fitted using the NRTL model. It was found that both LTTMs show a competitive performance compared to existing extracting agents. It was also established that both in the {hexane + ethanol} and {heptane + ethanol} separation, the LC(2:1) showed higher distribution coefficient than the GC(1:1), while the opposite trend was found for the selectivity values.
U2 - 10.1016/j.fluid.2015.03.017
DO - 10.1016/j.fluid.2015.03.017
M3 - Article
SN - 0378-3812
VL - 394
SP - 71
EP - 82
JO - Fluid Phase Equilibria
JF - Fluid Phase Equilibria
ER -