Precipitation of quercetin and nicotinamide in carbon dioxide + ethanol systems at high pressures: phase equilibrium data for antisolvent processes

Abstract The dataset obtained in this work comprise original new data on the phase equilibrium of ternary systems CO2 + ethanol + quercetin (QCN), CO2 + ethanol + nicotinamide (NIC), and the quaternary system CO2 + ethanol + QCN + NIC with a molar ratio of 1:1 (QCN:NIC), which comprehension of phase behavior can be useful to establish experimental conditions for further co-precipitation, co-crystallization or related particle-obtaining processes with QCN and/or NIC at elevated pressures by antisolvent techniques. The data were obtained with the synthetic-visual method at temperatures of 308.15, 318.15, and 328.15 K and pressures up to 10.17 MPa. The vapor-liquid equilibrium (VLE) with or without the presence of a solid phase (VLSE) was observed for all systems evaluated. For ternary systems, VLSE occurred at all temperatures from CO2 molar fractions between 0.7625 and 0.8499 for QCN, and close to 0.9 for NIC, at solid concentrations ranging from 0.02 to 0.06 %mol of solute in ethanol. Solid presence did not considerably alter the binary VLE behavior of solvent/antisolvent mixtures in terms of transition pressures, and the Peng-Robinson equation of state (PR-EoS) fitted well to the data considering systems as pseudobinaries.