Estimation of NRTL Parameters Using Auto Vapor^|^#8211;Liquid Equilibrium Measuring Equipment and Application of Distillate Curve Map to Batch Distillation

The Antoine constants and the NRTL parameters were determined for a system of water+propyleneglycol monomethyl ether (PGME)+propyleneglycol monomethyl ether acetate (PGMEA) using automatic vapor-liquid equilibrium measuring equipment. First, the NRTL parameters of a methanol+ethanol+water system and an acetone+methanol+water system were determined using the equipment. With these parameters, a distillate curve map was plotted to trace the vapor phase compositions of the residual curve map calculations, and this map was compared with the distillate trajectory of batch distillation. For the system of water+PGME+PGMEA, the distillate trajectory of batch distillation was examined by drawing the distillate curve map for the case in which the distillate in the region of liquid-liquid equilibrium was divided into two phases and the oil phase was returned to the still. These studies showed the possibility of evaluating batch distillation for systems with unknown physical properties using this equipment and the distillate curve map.