Separation of dichlorophenols
AssigneeMonsanto Technology LLC
InventorsKam-To Wan, Eduardo A. Casanova, John H. Ahn, Junqiu Yang
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Abstract
Various processes for the separation of a mixture containing dichlorophenols are described. In various aspects, the present invention relates to separation processes that produce an extract enriched in 2,4-dichlorophenol content and an extract enriched in 2,5-dichlorophenol content. The present invention further relates to various processes that integrate with these separation processes, such as a process for producing 3,6-dichloro-2-methoxybenzoic acid (dicamba) or salt or ester thereof or a process for producing 2,4-dichlorophenoxyacetic acid (2,4-D) or salt or ester thereof.
Claims20
A process for producing an aqueous extract comprising 2,5-dichlorophenol and/or a salt thereof, the process comprising:
- feeding a chlorophenol feed mixture comprising 2,5-dichlorophenol and 2,4-dichlorophenol to a fractional liquid-liquid extraction (FLLE) zone comprising a rectifying section and a stripping section;
- feeding an organic solvent to the stripping section of the FLLE zone;
- feeding an aqueous solution comprising base to the rectifying section of the FLLE zone;
- contacting the feed mixture with the organic solvent and the aqueous solution comprising base in the FLLE zone, wherein at least a portion of the 2,5-dichlorophenol is transferred to an aqueous phase and at least a portion of the 2,4-dichlorophenol is transferred to an organic phase comprising the organic solvent;
- feeding an aqueous solution comprising acid into the stripping section of the FLLE zone;
- removing the aqueous extract comprising 2,5-dichlorophenol and/or a salt thereof in the aqueous phase from the stripping section of the FLLE zone, wherein the weight ratio of total 2,5-dichlorophenol to total 2,4-dichlorophenol in the aqueous extract is greater than the weight ratio of 2,5-dichlorophenol to 2,4-dichlorophenol in the chlorophenol feed mixture;
- and
- removing an organic extract comprising 2,4-dichlorophenol in the organic phase from the rectifying section of the FLLE zone.
Dependencies are inferred from the claim text.