Extraction of phenols: Ii. distribution data for binary and multicomponent mixtures of phenols, countercurrent extraction performance and model validation

The distribution of binary mixtures of phenol with o-, m- or p-cresol between aqueous solutions of NaOH and toluene or methyl-isobutyl-ketone (MIBK) was investigated. A mathematical model of the distribution was formulated and its parameters were evaluated for each phenol/cresol/solvent combination. The extraction of phenolics from a coal tar fraction with aqueous solutions of sodium phenates was carried out in a countercurrent cascade of four equilibrium stages. The back extraction of phenolics from the aqueous extract was carried out as a triple extraction with pure solvent. A mathematical simulation of the multicomponent, multistage experiments was realized with the DOOM algorithm using an extension of the equilibrium model, formulated for binary mixtures. On a etudie la distribution de melanges binaires de phenol et de o-, m- ou p-cresol entre des solutions aqueuses de NaOH et de toluene ou methyl-isobutyl-cetone (MIBK). On a mis au point un modele mathematique de cette distribution et evalue ses parametres pour chaque combinaison de phenol/cresol/solvant. Ľextraction des phenoliques a partir ďune fraction de goudron de houille avec des solutions aqueuses de phenates de sodium a ete realisee dans une cascade a contre-courant possedant quatre plateaux ďequilibre. La retroextraction des phenoliques a partir du melange aqueux a ete realisee sous la forme ďune triple extraction au moyen de solvant pur. On a effectue une simulation mathematique des experiences a composantes multiples et multietagees avec ľalgorithme DOOM en utilisant une extension du modele ďequilibre formule pour les melanges binaires.