Solvent extraction was evaluated as a potential treatment method for wastewaters generated during the manufacture of acetic acid. Possible goals for an extraction process were considered. For the wastewater samples studied, extraction appeared to be too expensive to be practical unless recovery of a marketable chemical were possible. Long-chain, tertiary alkyl amines, dissolved in organic diluents, appeared to be the most promising extractants, except for certain wastewaters containing chlorinated acetaldehydes. Amine extractants were studied extensively in small-scale experiments to determine phase equilibria, extractant regenerability, mass-transfer characteristics, and emulsification tendencies. A cost estimate was prepared for an extraction process to recover acetic acid from a 22,700-kg/h (100-gpm) wastewater containing 5 wt.% acid. Estimated direct-fixed-capital was $1,030,000, with an annual operating cost of $253,000/year ($5.90/1000 gal), resulting in a return on investment before taxes (ROIBT) of 244% per year. The ROIBT, for a 1 wt.% acetic acid wastewater was only about 30%; however, this might be increased by further optimization of the amine/diluent combination.

"April 1980." Includes bibliographical references (pages 152-157). Prepared by University of California, Berkeley, Department of Chemical Engineering, for U.S. Environmental Protection Agency, Office of Research and Developmment, Robert S. Kerr Environmental Research Laboratory, Ada, Oklahoma, under EPA grant no. Contract Number: R803773.