PHASE-EQUILIBRIA OF TERNARY AND QUATERNARY SYSTEMS CONTAINING CARBON-DIOXIDE, WATER, ISOPROPANOL, AND GLUCOSE

Vapor-liquid equilibrium data have been measured for the ternary carbo n dioxide-isopropanol-water system and for the quaternary carbon dioxi de-isopropanol-water-glucose system at 313 and 333 K and at pressures between 13.8 and 30.0 MPa. For the quaternary system, densities were a lso obtained. A special high-pressure apparatus with vapor-phase recir culation and a sample bomb placed in the recirculation loop was used f or the measurements.1 The results show a phase behavior in the ternary system similar to that described in the literature at lower pressures . In the quaternary system, glucose concentrations in the vapor phase vary between 4.4 x 10(-4) and 0.11 mol %. While the glucose concentrat ion is strongly dependent on the vapor-phase concentration of isopropa nol and water, pressure and vapor-phase density do not influence the s olubility of glucose in the vapor phase significantly. Comparing the e ffect of isopropanol and ethanol on the entrainment of glucose in the vapor phase, it is evident that while the measured maximum glucose sol ubilities in the vapor phase are of the same order of magnitude (0.11 mol % at 13.79 MPa, 313.15 K for the isopropanol system and 0.17 mol % at 25.0 MPa, 313.15 K for the ethanol system), higher pressures are n eeded with ethanol as a cosolvent to achieve the same glucose solubili ties possible with isopropanol.