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Esterification‐coupled extraction of organic acids: Partition enhancement and underlying reaction and distribution equilibria
Author(s) -
AiresBarros M. R.,
Cabral J. M. S.,
Willson R. C.,
Hamel J.F. P.,
Cooney C. L.
Publication year - 1989
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260340705
Subject(s) - partition coefficient , chemistry , partition (number theory) , extraction (chemistry) , distribution (mathematics) , chromatography , organic chemistry , mathematics , mathematical analysis , combinatorics
A novel means of extracting carboxylic acids from aqueous solutions is described which involves the use of a lipolytic enzyme to convert the acid to a more hydrophobic ester. A water‐immiscible long‐chain alcohol serves both as a reactant in esterifying the acid, and as a solvent for extraction of the ester. Radiochemical tracer studies of the underlying reaction and extraction equilibria established that a low equilibrium concentration of ester (0.04–0.5m M ) in the presence of water is counterbalanced by the high distribution coefficient of the ester (220–3380, wt. basis). The net result is a substantial (4‐ to 15‐fold) increase in the apparent distribution coefficient of the acid; 80%–95% of the extracted acid is in the esterified form. The method is applicable to a variety of alcohols and acids.