INSTRUMENT FOR EVALUATING PHASE-BEHAVIOR OF MIXTURES FOR SUPERCRITICAL-FLUID EXPERIMENTS

Fluid phase behavior has a profound impact on supercritical fluid chro matography performance. The effect of fluid phase behavior on supercri tical fluid extraction performance has not been studied. Generally, me thods available to generate phase diagrams of fluid mixtures are time- consuming. This paper describes relatively easily constructed instrume ntation for the rapid screening of fluid mixtures to determine whether or not they are single phase. Either scattered or transmitted light c an be used to probe the phase behavior of the fluids. Examples using C O2/methanol and CO2/water are presented. The phase behavior of multico mponent mixtures of CO2 or Freon (R22, chlorodifluoromethane) with met hanol/triethylamine/water was determined.