Method of recovering carboxylic acids from dilute solutions
AssigneeGlitsch, Inc.
InventorsRanda W. Wytcherley, Joseph C. Gentry, Ronald G. Gualy
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Abstract
A method for recovering carboxylic acids from a dilute aqueous solution thereof having a concentration below about ten percent (10%) by weight, which includes passing the dilute acid solution through a reverse osmosis separator, thereby producing a permeate substantially free of acid and a retentate having an acid concentration above about ten percent (10%) by weight. The retentate is contacted with a liquid extractant for acids to produce an acid-rich extractate and an acid-free raffinate. The acid is then recovered from the acid-rich extractate.
Claims11
A method for recovering carboxylic acids from a dilute aqueous acid solution, said dilute acid solution having an acid concentration below about ten percent (10%) by weight, and containing one or more impurities from the class consisting of aromatic carboxylic acids, metallic ions, free metal particles, organic or inorganic salts, straight chain carboxylic acids having more than five (5) carbon atoms and sugars, comprising:
- removing said impurities from said dilute aqueous solution;
- passing said dilute acid solution through a membrane separator having a semi-permeable membrane, to thereby produce an aqueous permeate substantially free of acid and an aqueous retentate having an acid concentration more concentrated than the initial concentration of said dilute acid solution;
- treating said retentate in an acid separation step to thereby produce a further concentrate acid solution and a substantially acid-free raffinate;
- and
- recovering acid from said further concentrate acid solution.
Dependencies are inferred from the claim text.