Phenol recovery from phenolic resin manufacturing: Viability of the emulsion pertraction technology

In this paper, the viability of emulsion pertraction technology (EPT) for phenol recovery from the aqueous condensates obtained in the manufacturing of phenolic resins is described. This waste is highly concentrated in phenol (15–25 wt%) and formaldehyde (10–15 wt%). The experimental work was performed using real effluents of a phenolic resin producer. The simultaneous selective extraction and recovery of phenol from the condensate is performed in a single hollow fiber membrane contactor. Kerosene and its mixtures with a highly effective phenol extractant, Cyanex 923, were used as organic solvents. Phenol was transferred to the caustic stripping phase to give a final phenol concentration in the treated waste less than 0.5 wt%, whereas formaldehyde remained in the feed, thus providing the required selectivity. Phenol recovery was attained after acidification of the concentrated stripping phase.