Salt Effects on the Recovery of Phenol by Liquid‐Liquid Extraction with Cyanex 923

Abstract

In this work, the effect of salt addition on the recovery of phenol from a 46 g/L aqueous solution simulating a phenolic resin plant effluent by liquid‐liquid extraction at 298 K has been studied by using an organic phase containing 0.6 M Cyanex 923 extractant in ShellSol T. Addition of sodium sulfate, potassium nitrate, and sodium chloride to the aqueous phase was tested and sodium chloride was selected. Based on the obtained results, a study of phenol recovery process was undergone by taking advantage of the salting‐out effect. Equilibrium curves are presented for liquid‐liquid extraction with and without salt addition to the aqueous phase. An integrated process involving salting‐out and liquid‐liquid extraction was proposed. The stripping concentrates can be reused for phenolic resin production.

Keywords:

• Phenolic resins
• liquid‐liquid extraction
• phenol
• salt addition
• salting‐out

Acknowledgements

The authors would like to thank Eng. Francelino Fernandes for his helpful comments, the company FUNDIPOR–Production of Products for Foundry, Lda. (Oporto) for the phenolic resins effluent given to be studied in this work, Margarida Sampaio for her help in part of the experimental work and Shell Chemicals, Ltd. and Cytec Inc. for providing the reagent samples. The financial support of FCT and AdI (Portuguese Government Funding Agencies) is also acknowledged.