Liquid–Liquid Equilibrium Data and NRTL Correlation for Glycerol Carbonate Extraction from Glycerol Using 2‑Pentanone, Cyclohexanone, and 4‑Methyl-2-pentanone at 423.2–443.2 K

To identify suitable extractants for extractive enhanced glycerol-CO2 carbonylation, liquid–liquid equilibrium data were determined for glycerol–glycerol carbonate systems with 2-pentanone, cyclohexanone, and 4-methyl-2-pentanone at 423.2, 433.2, and 443.2 K under a pressure of 1.5 MPa. The efficacy of the three extractants in the extraction of glycerol carbonate from glycerol was evaluated using distribution coefficients and extractive selectivity. Among the extractants, cyclohexanone possessed the highest distribution coefficient (>1) and superior extraction capability, while 4-methyl-2-pentanone exhibited the best selectivity for glycerol carbonate over glycerol. The liquid–liquid equilibrium data were then correlated using the Non-Random Two-Liquid (NRTL) model, and the corresponding binary interaction parameters were determined. The regressed parameters effectively reproduced the phase equilibrium trends observed for all studied systems. This work provides fundamental data and parameters for the selection of extractant to enhance the glycerol-CO2 carbonylation through extractive reactions as well as for subsequent process development and optimization for the carbonylation.