Hops-extract–ethanol solutions were contacted counter-currently with dense CO2 in a 0.22 m column at temperatures of (313.2–353.2) K, pressures of (5.0–12.0) MPa, at solute-free solvent-to-feed (S/F) mass ratios of 3.8 and 8.6 for fractionating flavor and bitter compounds. Flavor-purity ratio (Pf) defined as flavor-compound mass over identified-compound mass was about 1.0 at 313.2 K, 6 MPa at S/F = 8.6. At these conditions, flavor-recovery ratio (Rf) defined as flavor-compound mass over feed flavor-compound mass was less than 0.03. At 353.2 K, 12.0 MPa at S/F = 8.6, maximum column productivity (Pf = 0.76, Rf = 0.69) was obtained. Conditions giving maximum purity and highest selectivity (Pf = 0.99, Rf = 0.27) were 333.2 K, 8.0 MPa at S/F = 8.6. In fractionation of feed solutions containing ethanol, column performance is dominated by ethanol distribution that is conveniently manipulated with conditions of the CO2.
- Distribution coefficient