THE SEPARATION OF PHENOLIC COMPOUNDS FROM NEUTRAL OILS AND NITROGEN BASES

摘要

Liquid-liquid extraction with a solvent system consisting of triethylene glycol as selective solvent, water as co-solvent and hexane as countersolvent is proposed for the separation of phenolic compounds from neutral oils and nitrogen bases. Solvent selection was by means of computer-aided molecular design. Liquid-liquid equilibria for the solvent system plus phenolic compounds, neutral oils and nitrogen bases were determined. The effect of solvent ratios on the desired separation are illustrated on the basis of separation factors and percentage recoveries of phenolic compounds. The three-parameter NRTL model was fitted to the equilibrium data and was used in the optimisation of a multistage countercurrent extraction process. Pilot-plant tests performed on an industrial heavy naphtha stream yielded a final phenolic product purity of 99.75% and phenolic recovery in excess of 91%.