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## Continuous Wash ofRaffinate from Forward Extraction 

For example 41, the sulfuric acid-lean raffinate of Example 36, comprising glycolic acid, glycolate oligomers, and water was contacted continuously with a heptane wash solvent as the continuous phase in the Karr colunm described above to remove additional 2-ethylhexanoic acid and TEHA. Simi› larly for Example 42, the raffinate from Example 39 was contacted with heptane in the continuous colunm to remove additional 2-ethylhexanoic acid and TEHA. Feed composi› tions, flow rates, feed locations, and temperature of the wash experiments are summarized in Table 18. In each experiment, the colunm reached steady state within an hour and was run continuously for six to eight hours, with sampling occurring every one to two hours. Averaged recoveries ofTEHA, 2-eth› y lhexanoic acid, and heptane to wash extract product over the time of steady state operation are given in Table 19. 

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## Examples 41-42 

## Back Extractions of Sulfuric Acid-Rich Solvents in Continuous Column 

Sulfuric acid-rich extracts compnsmg sulfuric acid, TEHA, 2-ethylhexanoic acid, and heptane derived from the forward extraction of hydrocarboxylation effluents were fed to the continuous Karr colunm at a temperature of 70° C. as described above and contacted with an aqueous formalde- hyde extraction solvent ( continuous phase). The sulfuric acid-rich extracts were introduced to the Karr colunm at location F5 and the aqueous formaldehyde solvent was intro› duced at location Fl. Feed and solvent compositions, and flow rates of the forward extraction experiments are summa- 

rized in Table 20. In each experiment, the colurmi reached steady state within an hour and was run continuously for six to eight hours, with sampling occurring every one to two hours. Averaged recoveries of TEHA, 2-ethylhexanoic acid, and heptane to the raffinate product, and glycolic acid and sulfuric acid to the formaldehyde extract product over the time of steady state operation are given in Table 21. 

## Examples 43-48 

