Predictive distribution coefficient (pKD) model for hops extract fractionation in high-pressure CO2 - ethanol - water solvent systems.

Vapor-liquid distribution coefficients (K -values) of seven compounds contained in hops-extract were measured (total of 217 data) for high pressure CO 2 - ethanol aqueous solution systems at (313 to 353) K and (10 to 20) MPa with a continuous flow apparatus. Using all available experimental solute K -values including newly measured data and those in CO 2 + ethanol binary solvent systems (total of 322 data), a predictive distribution coefficient (pKD) model was developed based on dimensionless groups and the entropy-based solubility parameter. The pKD model allows correlation of available K -value data and provides a method for predicting K -values of non-hops extracts related solutes (salicylic acid, methyl salicylate, 4-cyano-4′-hydroxybiphenyl) in CO 2 - ethanol - water systems. [Display omitted] [ABSTRACT FROM AUTHOR]