Feed purification method

Abstract

A method for separating chemical impurities from a feed includes providing a fermentation broth comprising a blend of carboxylic acids, adjusting the pH of the broth to a more acidic pH, heating the fermentation broth to create water vapor from the water in the broth, providing an organic extraction solvent having a density less than the density of water, condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid, extracting the cyclohexane carboxylic acid from the condensed water droplets into an organic extraction solvent layer by contacting the condensed water vapor droplets with the organic extraction solvent and separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities. The method results in the separation and removal of unwanted impurities in the feed from a target compound and provides a high yield of the target compound for downstream processing.

Description

[0001] FEED PURIFICATION METHOD

[0002] TECHNICAL FIELD

[0003] The disclosure relates to a method of purifying a starting material feed by removing at least one undesired chemical compound present in the feed from at least one desired chemical compound in the feed. The disclosure relates to a method of purifying a starting material feed by removing at least one undesired organic acid contained in the feed from at least one desired organic acid in the feed.

[0004] BACKGROUND

[0005] The carboxylic acid cyclohexane carboxylic acid is used in chemical reactions to prepare flavor and taste masking compounds for use in connection with food and pharmaceutical products.

[0006] Cyclohexane carboxylic acid may be prepared by a fermentation method. The fermentation broth containing the cyclohexane carboxylic acid may also contain further aromatic acids 1 -cyclohexene- 1 -carboxylic acid and benzoic acid and aliphatic carboxylic acids crotonic acid and acetic acid. These other organic acids have the following chemical structures:

[0007] Cyclohexanec 1-cyclohexene-l- Benzoic acid Crotonic acid Acetic acid arboxylic add carboxylic acid

[0008] These aromatic and aliphatic organic acids present in the fermentation broth are considered undesired impurities as they interfere with downstream esterification reactions of cyclohexane carboxylic acid to prepare flavor and taste masking compounds. The organic acids pose a significant challenge due to their structural similarities to cyclohexane carboxylic acid and are difficult to separate from cyclohexane carboxylic acid. What is needed in the art is an improved method of purifying a feed containing cyclohexane carboxylic acid among other aromatic and / or aliphatic organic carboxylic acids that has a shorter process cycle time, consumes less energy, and consumes less organic solvent.

[0009] SUMMARY OF ILLUSTRATIVE EMBODIMENTS

[0010] According to a first illustrative embodiment, disclosed is a method for extracting a cyclohexane carboxylic acid from a blend of carboxylic acid compounds comprising the cyclohexane carboxylic acid and carboxylic acid impurities present in an aqueous feed, the method comprising providing a feed comprising the blend of carboxylic acids; adjusting the pH of the feed containing the blend of carboxylic acids to a more acidic pH; heating the aqueous feed containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous feed; providing an organic extraction solvent having a density less than the density of water; condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid; extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities.

[0011] According to a second illustrative embodiment, disclosed is a purified feed produced by the process comprising providing a feed comprising the blend of carboxylic acids; adjusting the pH of the feed containing the blend of carboxylic acids to a more acidic pH; heating the aqueous feed containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous feed; providing an organic extraction solvent having a density less than the density of water; condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid; extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities.

[0012] According to a third illustrative embodiment, disclosed is disclosed is a method for extracting a cyclohexane carboxylic acid from a blend of carboxylic acid compounds comprising the cyclohexane carboxylic acid and carboxylic acid impurities present in an aqueous fermentation broth, the method comprising providing a fermentation broth comprising the blend of carboxylic acids; adjusting the pH of the fermentation broth containing the blend of carboxylic acids to a more acidic pH; heating the aqueous fermentation broth containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous fermentation broth; providing an organic extraction solvent having a density less than the density of water; condensing the water vapor into condensed water droplets cyclohexane carboxylic acid; extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities.

[0013] According to a fourth illustrative embodiment, disclosed is a purified feed produced by the process comprising a method for extracting a cyclohexane carboxylic acid from a blend of carboxylic acid compounds comprising the cyclohexane carboxylic acid and carboxylic acid impurities present in an aqueous fermentation broth, the method comprising: providing a fermentation broth comprising the blend of carboxylic acids; adjusting the pH of the fermentation broth containing the blend of carboxylic acids to a more acidic pH; heating the aqueous fermentation broth containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous fermentation broth; providing an organic extraction solvent having a density less than the density of water; condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid; extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities.

[0014] According to a fifth illustrative embodiment, disclosed is a method comprising (a) preparing a purified feed comprising (a-1) providing a feed comprising the blend of carboxylic acids; (a-2) adjusting the pH of the feed containing the blend of carboxylic acids to a more acidic pH; (a-3) heating the aqueous feed containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous feed; (a-4) providing an organic extraction solvent having a density less than the density of water; (a-5) condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid; (a-6) extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and (a-7) separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities, and (b) a downstream esterification reaction using purified feed.

[0015] According to a sixth illustrative embodiment, disclosed is a method comprising (a) preparing a purified fermentation broth comprising (a-1) providing a fermentation broth comprising the blend of carboxylic acids; (a-2) adjusting the pH of the fermentation broth containing the blend of carboxylic acids to a more acidic pH; (a-3) heating the aqueous fermentation broth containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous fermentation broth; (a-4) providing an organic extraction solvent having a density less than the density of water; (a-5) condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid; (a-6) extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and (a-7) separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities, and (b) a downstream esterification reaction using purified fermentation broth.

[0016] According to a seventh illustrative embodiment, disclosed is the use of a purified feed prepared according to a method comprising (a-1) providing a feed comprising the blend of carboxylic acids; (a-2) adjusting the pH of the feed containing the blend of carboxylic acids to a more acidic pH; (a-3) heating the aqueous feed containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous feed; (a-4) providing an organic extraction solvent having a density less than the density of water; (a-5) condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid; (a-6) extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and (a-7) separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities, in an esterification reaction.

[0017] According to an eighth illustrative embodiment, disclosed is the use of a purified fermentation broth prepared according to a method comprising (a-1) providing a fermentation broth comprising the blend of carboxylic acids; (a-2) adjusting the pH of the fermentation broth containing the blend of carboxylic acids to a more acidic pH; (a-3) heating the aqueous fermentation broth containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous fermentation broth; (a-4) providing an organic extraction solvent having a density less than the density of water; (a-5) condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid; (a-6) extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and (a-7) separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities, in an esterification reaction.

[0018] According to a ninth illustrative embodiment, disclosed is the use of a purified feed prepared according to a method comprising (a-1) providing a feed comprising the blend of carboxylic acids; (a-2) adjusting the pH of the feed containing the blend of carboxylic acids to a more acidic pH; (a-3) heating the aqueous feed containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous feed; (a-4) providing an organic extraction solvent having a density less than the density of water; (a-5) condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid; (a-6) extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and (a-7) separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities, to prepare an esterification reaction product.

[0019] According to an tenth illustrative embodiment, disclosed is the use of a purified feed prepared according to a method comprising (a-1) providing a fermentation broth comprising the blend of carboxylic acids; (a-2) adjusting the pH of the fermentation broth containing the blend of carboxylic acids to a more acidic pH; (a-3) heating the aqueous fermentation broth containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous fermentation broth; (a-4) providing an organic extraction solvent having a density less than the density of water; (a-5) condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid; (a-6) extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and (a-7) separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities, to prepare an esterification reaction product.

[0020] According to an eleventh illustrative embodiment, disclosed is an esterification product prepared by the reaction of a purified feed prepared according to a method comprising (a-1) providing a feed comprising the blend of carboxylic acids; (a-2) adjusting the pH of the feed containing the blend of carboxylic acids to a more acidic pH; (a-3) heating the aqueous feed containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous feed; (a-4) providing an organic extraction solvent having a density less than the density of water; (a-5) condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid; (a-6) extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and (a-7) separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities, with another chemical reactant sufficient to form the esterification reaction product.

[0021] According to a twelfth illustrative embodiment, disclosed is an esterification product prepared by the reaction of a purified fermentation broth prepared according to a method comprising (a-1) providing a fermentation broth comprising the blend of carboxylic acids; (a- 2) adjusting the pH of the fermentation broth containing the blend of carboxylic acids to a more acidic pH; (a-3) heating the aqueous fermentation broth containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous fermentation broth; (a-4) providing an organic extraction solvent having a density less than the density of water; (a-5) condensing the water vapor into condensed water droplets containing the blend of carboxylic acid compounds; (a-6) extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and (a-7) separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities, with another chemical reactant sufficient to form the esterification reaction product.

[0022] BRIEF DESCRIPTION OF ILLLUSTRATIVE DRAWINGS

[0023] FIGURE 1 is a flow chart for an illustrative embodiment of the disclosed extraction method.

[0024] FIGURE 2 is a flow chart for an illustrative embodiment of an esterification method using cyclohexane carboxylic acid extracted from a fermentation broth by the presently disclosed extraction method.

[0025] DETAILED DESCRIPTION OF ILLUSTATIVE EMBODIMENTS

[0026] The following text sets forth a broad description of numerous different embodiments of the present disclosure. The description is to be construed as exemplary only and does not describe every possible embodiment since describing every possible embodiment would be impractical, if not impossible. It will be understood that any feature, characteristic, component, composition, ingredient, product, step or methodology described herein can be deleted, combined with or substituted for, in whole or part, any other feature, characteristic, component, composition, ingredient, product, step or methodology described herein. Numerous alternative embodiments could be implemented, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims.

[0027] The terms “comprises,” “comprising,” “has,” “having,” “includes,” “including,” “contains,” “containing,” or any other variation are open-ended and are intended to cover a non-exclusive inclusion of elements, such that an article, apparatus, compound, composition, combination, method, or process that “comprises,” “has,” or “includes,” or “contains” a recited list of elements does not include only those elements but may include other elements not expressly listed, recited or written in the specification or claims. An element or feature proceeded by the language “comprises . . .a,” “contains . . . a,” “has . . . a,” or “includes . . .a” does not, without more constraints, preclude the existence or inclusion of additional elements or features in the article, apparatus, compound, composition, combination, method, or process that comprises, contains, has, or includes the element or feature.

[0028] The terms “a” and “an” are defined as one or more unless expressly stated otherwise or constrained by other language herein. An element or feature proceeded by “a” or “an” may be interpreted as one of the recited element or feature, or more than one of the element or feature.

[0029] The terms “about,” “approximately,” “essentially,” “substantially,” any other version thereof, or any other similar relative term, or similar term of approximation, are defined as being close to as understood by one having ordinary skill in the art. By way of non-limiting, illustrative embodiments, these terms are defined to be within 20 % of a recited value, or defined to be within 10% of a recited value, or defined to be within 5% of a recited value, or defined to be within 4% of a recited value, or defined to be within 3% of a recited value, or defined to be within 2% of a recited value, or defined to be within 1% of a recited value, of defined to be within 0.75% of a recited value, or defined to be within 0.5% of a recited value, or defined to be within 0.25% of a recited value, or defined to be within 0.1% of a recited value.

[0030] It should be understood that when an amount in weight percent is described in the present disclosure, it is intended that any and every amount within the range, including the end points, is to be considered as having been expressly disclosed. For example, the disclosure of "a range of from about 1 to about 100" is to be read as indicating each and every possible number along the continuum between about 1 and about 100. It is to be understood that the inventors appreciate and understand that any and all data points within the range are to be considered to have been disclosed and specified, and that the inventors have possession of the entire range and all points within the range. When a concentration is expressed as “ppm”, the concentration is parts per million by weight based on the total weight of a component, compound, composition, or consumable. It should be understood that when a range of values is described in ppm, it is intended that any and every value within the range, including the end points, is to be considered as having been disclosed. For example, “a range of from 1 ppm to 1000 ppm” is to be read as indicating each and every possible number along the continuum between 1 and 1000. It is to be understood that the inventors appreciate and understand that any and all values within the range are to be considered to have been disclosed and specified, and that the inventors have possession of the entire range and all the values within the range.

[0031] For the avoidance of doubt, alternative and optional features indicated for a given aspect, component, feature, or parameter of the invention should, unless the context indicates otherwise, be regarded as having been disclosed in combination with any and all other alternative or optional features and the like as indicated for the same or other aspects, features and parameters of the invention.

[0032] Disclosed is a method of purifying a feed material, such as a feed comprising a fermentation broth containing at least one impurity to be removed. The method of purifying the feed material comprises extraction of a target organic acid from a fermentation broth containing at least one organic acid. According to certain illustrative embodiments, the method of purifying the feed material comprises extraction of a fermentation broth containing more than one organic acid. According to certain illustrative embodiments, the method of purifying the feed material comprises extraction of a fermentation broth containing at least one aromatic organic acid. According to certain illustrative embodiments, the method of purifying the feed material comprises extraction of a fermentation broth containing at least one aromatic carboxylic acid. According to certain illustrative embodiments, the method of purifying the feed material comprises extraction of a fermentation broth containing at least one aliphatic organic acid. According to certain illustrative embodiments, the method of purifying the feed material comprises extraction of a fermentation broth containing at least one aliphatic carboxylic acid. According to certain illustrative embodiments, the method of purifying the feed material comprises extraction of a fermentation broth containing at least one aromatic carboxylic acid and at least one aliphatic carboxylic acid.

[0033] According to certain illustrative embodiments, the extraction method results in extracting a cyclohexane carboxylic acid from a blend of carboxylic acid compounds comprising the cyclohexane carboxylic acid and carboxylic acid impurities present in an aqueous fermentation broth. The extraction method comprises providing a fermentation broth comprising the blend of carboxylic acids, such as a blend of at least one aromatic carboxylic acid and at least one aliphatic carboxylic acid. The pH of the fermentation broth containing the blend of carboxylic acids is adjusted to a pH in a range wherein cyclohexane carboxylic acid preferentially distills as compared to benzoic acid. According to certain embodiments, the pH of the fermentation broth containing the blend of carboxylic acids is adjusted to a pH in a range wherein cyclohexane carboxylic acid preferentially distills as compared to benzoic acid and crotonic acid. According to certain embodiments, the pH of the fermentation broth containing the blend of carboxylic acids is adjusted to a pH in the range of about 2 to about 6. The pH- adjusted aqueous fermentation broth containing the blend of carboxylic acid compounds is sufficiently heated to create water vapor from the water present in the aqueous fermentation broth. The water vapor is condensed into droplets containing the blend of carboxylic acid compounds. An organic extraction solvent having a density less than the density of water is provided and at least a portion of the cyclohexane carboxylic acid is extracted from the condensed water droplets into an organic extraction solvent layer by contacting the condensed water vapor droplets containing with the organic extraction solvent. The organic extraction solvent layer containing the cyclohexane carboxylic acid is separated from the aqueous layer containing the carboxylic acid impurities.

[0034] By way of illustration, and not in limitation, the at least one aromatic carboxylic acid contained in the fermentation broth comprises at least one of cyclohexane carboxylic acid, 1- cyclohexene-1 -carboxylic acid, and benzoic acid, and wherein the at least one aliphatic carboxylic acid contained in the fermentation broth comprises at least one of crotonic acid and acetic acid. According to certain illustrative embodiments, the at least one aromatic carboxylic acid contained in the fermentation broth comprises cyclohexane carboxylic acid, 1- cyclohexene-1 -carboxylic acid, and benzoic acid, and wherein the at least one aliphatic carboxylic acid contained in the fermentation broth comprises crotonic acid and acetic acid.

[0035] According to certain embodiments, the fermentation broth comprises from about 0.001 weight percent to about 0.01 weight percent cyclohexane carboxylic acid, from about 0.0001 weight percent to about 0.005 weight percent 1-cyclohexene-l-carboxylic acid, from about 0.002 weight percent to about 0.01 weight percent benzoic acid, from about 0.001 weight percent to about 0.01 weight percent crotonic acid, and from about 0.02 weight percent to about 0.05 weight percent acetic acid.

[0036] According to certain embodiments, the fermentation broth comprises from about 0.0015 weight percent to about 0.01 weight percent cyclohexane carboxylic acid, from about 0.00015 weight percent to about 0.004 weight percent 1-cyclohexene-l-carboxylic acid, from about 0.0025 weight percent to about 0.01 weight percent benzoic acid, from about 0.002 weight percent to about 0.005 weight percent crotonic acid, and from about 0.025 weight percent to about 0.04 weight percent acetic acid.

[0037] According to certain embodiments, the fermentation broth comprises from about 0.0018 weight percent to about 0.007 weight percent cyclohexane carboxylic acid, from about 0.00013 weight percent to about 0.003 weight percent 1 -cyclohexene- 1 -carboxylic acid, from about 0.0028 weight percent to about 0.011 weight percent benzoic acid, from about 0.003 weight percent to about 0.007 weight percent crotonic acid, and from about 0.022 weight percent to about 0.031 weight percent acetic acid.

[0038] The organic extraction solvent used to extract the condensed water droplets comprises an organic extraction solvent having a density less than 1 g / ml. According to certain embodiments, the organic extraction solvent has a density less than 0.990 g / ml, or 0.985 g / ml, or 0.980 g / ml, or 0.975 g / ml, or 0.970 g / ml, or 0.970 g / ml, or 0.965 g / ml, or 0.960 g / ml, or 0.955 g / ml, or 0.950 g / ml, or 0.945 g / ml, or 0.940 g / ml, or 0.935 g / ml, or 0.930 g / ml, or 0.925 g / ml, or 0.920 g / ml, or 0.915 g / ml, or 0.910 g / ml, or 0.905 g / ml, or 0.900 g / ml, or any other density less than 1 g / ml.

[0039] Without limitation, and only by way of example, the organic extraction solvent used to extract the condensed water droplets is selected from diethyl ether, esters such as methyl acetate, ethyl acetate, and butyl acetate, C6 to C8 alkanes such as hexane, ethers such as t-butyl methyl ether, cyclic aromatic hydrocarbons, including substituted cyclic aromatic hydrocarbons, such as toluene, and mixtures thereof.

[0040] The pH of the fermentation broth containing the blend of carboxylic acids is adjusted to a pH in the range of about 2 to about 6 prior to extraction with the organic extraction solvent. According to certain embodiments, the pH of the fermentation broth is adjusted to a pH in the range of about 2 to about 5.5, or about 2 to about 5, or about 2 to about 4.5, or from about 2 to about 4, or from about 2 to about 3.5, or from about 2 to about 3, or from about 3 to about 6, or from about 3 to about 5.5, or from about 3 to about 5, or from about 3 to about 5, or from about 3 to about 4.5, or from about 3 to about 4, or from about 4 to about 6, or from about 4 to about 5.5, or from about 4 to about 5, or from about 4 to about 4.5, or from about 4 to about 4.1, or from about 4 to about 4.2, or from about 4 to about 4.3, or from about 4 to about 4.4, or from about 4.2 to about 4.5, or from about 4.2 to about 4.4, or to a pH in any other the range within the range of about 2 to about 6.

[0041] According to certain embodiments, 90 weight percent or greater, or 91 weight percent or greater, or 92 weight percent or greater, or 93 weight percent or greater, or 94 weight percent or greater, or 95 weight percent or greater, or 96 weight percent or greater, or 97 weight percent or greater, or 98 weight percent or greater, or 99 weight percent or greater, or 99.1 weight percent or greater, or 99.2 weight percent or greater, or 99.3 weight percent or greater, or 99.4 weight percent or greater, or 99.5 weight percent or greater, or 99.6 weight percent or greater, or 99.7 weight percent or greater, or 99.8 weight percent, or greater, or 99.9 weight percent or greater, 100 weight percent, of the cyclohexane carboxylic acid contained in the fermentation broth is extracted.

[0042] According to certain illustrative embodiments, 50 weight percent or greater, or 55 weight percent or greater, or 60 weight percent or greater, or 65 weight percent or greater, or 70 weight percent or greater, or 75 weight percent or greater, or 80 weight percent or greater, or 85 weight percent or greater, or 90 weight percent or greater, or 95 weight percent or greater, of the 1 -cyclohexene carboxylic acid contained in the fermentation broth remains in the separated aqueous layer.

[0043] According to certain illustrative embodiments, 90 weight percent or greater, or 91 weight percent or greater, or 92 weight percent or greater, or 93 weight percent or greater, or 94 weight percent or greater, or 95 weight percent or greater, or 96 weight percent or greater, or 97 weight percent or greater, or 98 weight percent or greater, or 99 weight percent or greater, or 99.1 weight percent or greater, or 99.2 weight percent or greater, or 99.3 weight percent or greater, or 99.4 weight percent or greater, or 99.5 weight percent or greater, or 99.6 weight percent or greater, or 99.7 weight percent or greater, or 99.8 weight percent, or greater, or 99.9 weight percent or greater, 100 weight percent, of the benzoic acid contained in the fermentation broth remains in the separated aqueous layer.

[0044] According to certain illustrative embodiments, 50 weight percent or greater, or 55 weight percent or greater, or 60 weight percent or greater, or 65 weight percent or greater, or 70 weight percent or greater, or 75 weight percent or greater, or 80 weight percent or greater, or 85 weight percent or greater, or 90 weight percent or greater, or 95 weight percent or greater, of the crotonic acid contained in the fermentation broth remains in the separated aqueous layer.

[0045] According to certain illustrative embodiments, the extraction method optionally comprises a step of removing biomass from the fermentation broth before the step of heating the aqueous fermentation broth containing the blend of carboxylic acids. Without limitation, the step of removing the biomass from the fermentation broth before the step of heating the aqueous fermentation broth containing the blend of carboxylic acids comprises filtering the fermentation broth to remove cells and / or cell debris from the fermentation broth. The step of filtering the fermentation broth to remove cells and / or cell debris is conducted for a period of time from about 5 to about 20 hours, or from about 5 to about 18 hours, or from about 5 to about 16 hours, or from about 5 to about 14 hours, or from about 5 to about 12 hours, or from about 5 to about 10 hours, or from about 10 to about 18 hours, or from about 10 to about 16 hours, or from about 10 to about 14 hours, or from about 10 to about 12 hours, or for any other period of time within the range from about 5 to about 20 hours.

[0046] According to certain embodiments, the separation method comprises optionally removing at least a portion of the water from the fermentation broth before the step of heating the aqueous fermentation broth containing the blend of carboxylic acids. According to certain embodiments, the optional step of removing a portion of the water from the fermentation broth is conducted after the optional step of removing the cells and / or cell debris and before the step of heating the aqueous fermentation broth containing the blend of carboxylic acids. Without limitation, the optional step of removing at least a portion of the water from the fermentation broth before the step of heating the aqueous fermentation broth containing the blend of carboxylic acids comprises conducting reverse osmosis or vacuum evaporation on the fermentation broth. According to certain embodiments, the step of removing at least a portion of the water from the fermentation broth before the step of heating the aqueous fermentation broth containing the blend of carboxylic acids comprises conducting reverse osmosis on the fermentation broth. The step of reverse osmosis comprises passing the fermentation broth through a reverse osmosis membrane. The step of conducting reverse osmosis on the fermentation broth to remove cells and / or cell debris is conducted for a period of time from about 5 to about 20 hours, or from about 5 to about 18 hours, or from about 5 to about 16 hours, or from about 5 to about 14 hours, or from about 5 to about 12 hours, or from about 5 to about 10 hours, or from about 10 to about 18 hours, or from about 10 to about 16 hours, or from about 10 to about 14 hours, or from about 10 to about 12 hours, or for any other period of time within the range from about 5 to about 20 hours.

[0047] The extraction method optionally comprises removing residual organic extraction solvent from the organic solvent extraction layer after extracting the cyclohexane carboxylic acid from the aqueous fermentation broth. According to certain embodiments, the step of removing the residual organic extraction solvent layer comprises vacuum evaporation.

[0048] The extraction method is conducted using a continuous liquid-liquid apparatus or setup. According to certain embodiments, the extraction apparatus includes a round bottom flask, extractor, condenser, return conduit extending between the extractor and the flask, and a heating means to heat the contents of the flask. According to certain embodiments, the aqueous fermentation broth including a mixture carboxylic acids is added to the round bottom flask of the apparatus. An organic extraction solvent, such as ethyl acetate, is added to the extractor of the apparatus. The aqueous fermentation broth is heated in the round bottom flash until water vapor is created. The water vapor travels through a conduit to the condenser of the apparatus which is positioned on top of the extractor. The water vapor is condensed in the condenser to form water droplets containing the mixture of carboxylic acids. The condensed water droplets travel through the ethyl acetate extraction solvent which extracts the carboxylic acids and separates the layers into aqueous and organic extraction solvent layers. The bottom aqueous layer flows through a valve and conduit extending between the extractor and the round bottom flask to return to the flask. The carboxylic acids are separated in the water vapor traveling through the conduit between the flask and the condenser and are then extracted in the extractor. At a pH of about 4 to about 5, such as about 4.4 to about 4.7, the target cyclohexane carboxylic acid is more likely to be distilled with the water vapor as compared to acetic acid, benzoic acid, crotonic acid, or 1-cycloehexene-l -carboxylic acid due to differences in pka and volatilities, and once the water vapor is condensed, the target cyclohexane carboxylic acid is extracted by the ethyl acetate.

[0049] Additionally disclosed is a method of esterifying cyclohexane carboxylic acid extracted from a feed by the presently disclosed extraction method. According to certain embodiments, disclosed is a method of esterifying cyclohexane carboxylic acid extracted from a fermentation broth by the presently disclosed extraction method. The method comprises providing a fermentation broth comprising a blend of carboxylic acid compounds comprising the cyclohexane carboxylic acid and carboxylic acid impurities, extracting from the cyclohexane carboxylic acid from the fermentation broth containing the cyclohexane carboxylic acid and the carboxylic acid impurities in accordance with the presently disclosed extraction method, and reacting the extracted cyclohexane carboxylic acid with an alcohol to esterify the cyclohexane carboxylic acid.

[0050] FIGURE 1 depicts a process flow an illustrative embodiment (10) of the presently disclosure separation method. According to illustrative embodiment (10), a fermentation broth comprising a blend of aromatic organic acids and aliphatic organic acids is subject to separation step (20) to remove biomass, including cells and cellular debris, from the upstream fermentation process. The fermentation broth includes at least cyclohexane carboxylic acid, 1- cyclohexene-1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid. The fermentation broth is then subjected to a water removal step (30) passing the fermentation broth through a reverse osmosis membrane. The fermentation broth with a reduced water content following water removal step (30) is subjected to a pH adjustment step (40). Following the pH adjustment step (40), the fermentation broth is heated to create water vapor (50). At step (60), the water vapor created in step (50) is condensed into water droplets containing the carboxylic acids from the fermentation broth. The cyclohexane carboxylic acid is extracted from the water droplets with an organic extraction solvent at step (70). The organic solvent layer is separated from the aqueous layer at step (80).

[0051] FIGURE 2 depicts a process flow another illustrative embodiment (110) of the presently disclosure separation method. According to illustrative embodiment (110), a fermentation broth comprising a blend of aromatic organic acids and aliphatic organic acids is subject to separation step (120) to remove biomass, including cells and cellular debris, from the upstream fermentation process. The fermentation broth includes at least cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid. The fermentation broth is then subjected to a water removal step (130) passing the fermentation broth through a reverse osmosis membrane. The fermentation broth with a reduced water content following water removal step (130) is subjected to a pH adjustment step (140). Following the pH adjustment step (140), the fermentation broth is heated to create water vapor (150). At step (160), the water vapor created in step (150) is condensed into water droplets containing the carboxylic acids from the fermentation broth. The cyclohexane carboxylic acid is extracted from the water droplets with an organic extraction solvent at step (170). The organic solvent layer is separated from the aqueous layer at step (180). The product of the extraction method is used in a downstream esterification reaction (190) in which the purified cyclohexane carboxylic acid species is reacted with an alcohol to form the desired ester reaction product.

[0052] According to other illustrative embodiments, the extraction method includes coupling a distillation column to the extraction apparatus. The function of the distillation column is to fractionate steam vapor from the carboxylic acid mixture so that most of the acid by-products return to the boiling vessel while the steam vapor of the acid product travel through the column, condenses, and is extracted into the organic extraction solvent in the in the continuous liquidliquid extraction apparatus. According to this embodiment, the use of the distillation column in connection with the continuous liquid-liquid extractor decreases the concentrations of carboxylic acid by-products, namely, benzoic acid, cyclohexene carboxylic acid and crotonic acid in the water vapor while extracting the target product cyclohexane carboxylic acid. According to certain embodiments, when the extraction method uses the combination of the distillation column and continuous liquid-liquid extractor, the concentrations of the undesired acid by-products were decreased to undetectable levels by High Pressure Liquid Chromatography instrument, which demonstrates that an extract contains the target cyclohexane carboxylic acid product with less acid by-products.

[0053] EXAMPLES

[0054] Example 1

[0055] A fermentation broth containing 0.54g / L cyclohexane carboxylic acid, 1.08 g / L benzoic acid, 0.013 g / L cyclohexene carboxylic acid, 0.039 g / L crotonic acid and 2.33 g / L acetic acid was subjected to the presently disclosed extraction method to extract and enrich cyclohexane carboxylic acid. The initial pH of the fermentation broth was 8.94. 100 L of the fermentation broth was filtered through a 0.2 micron filter to remove biomass and evaporated under vacuum according the following conditions:

[0056] -55°C under 120 mBar vacuum for 1 hour, followed by

[0057] -55°C under 112 mBar vacuum for 30 minutes, followed by

[0058] -50°C under 96 mBar vacuum for 15 minutes, followed by

[0059] -53°C under 91 mBar vacuum for 20 minutes, followed by

[0060] -the vacuum was reduced to 88 mBar at 53°C.

[0061] The 465g residue of the fermentation broth was transferred to a 1-L flask and the vacuum evaporation was resumed for a period of two hours for a total evaporation time of about 5 hours. The weight of the fermentation broth residue following the vacuum evaporation was 148g. A sample of the fermentation broth residue was collected, filtered through a 0.2 micron filtered and analyzed by liquid chromatography. The concentration of the cyclohexane carboxylic acid in the sample of the fermentation broth tested was 5.47 g / L. Another sample of the fermentation broth was vacuum evaporated in a 2-L flask under the following conditions:

[0062] -53°C under 120 mBar vacuum for 15 minutes, followed by

[0063] -53°C under 88 mBar vacuum for 3 hours.

[0064] The weight of the fermentation broth residue following vacuum evaporation was 98g. A sample of the fermentation broth residue was collected, filtered through a 0.2 micron filtered and analyzed by liquid chromatography. The concentration of the cyclohexane carboxylic acid in the sample of the fermentation broth tested was 5.51 g / L. The 148g and 98g fermentation broth residues were combined for a total weight of 246 g. The pH of the combined residues was adjusted to about 4.5 with citric acid. A sample of the combined fermentation broth residue was collected, filtered through a 0.2 micron filtered and analyzed by liquid chromatography. The weight and concentration of the cyclohexane carboxylic acid in the combined fermentation broth residue tested 1.35 g and was 5.49 g / L, respectively.

[0065] The combined fermentation broth residue was subjected to extraction. A continuous liquid-liquid extraction apparatus or set-up comprising a round bottom flask, extractor, condenser, return conduit extending between the extractor and the flask, and a heating means to heat the contents of the flask was used for the liquid-liquid extraction. The 246 g fermentation broth residue was added to the 500 ml round bottom flask and 200 ml of the organic extraction solvent ethyl acetate was added to the extractor. The flask was heated to boil the contents of the flask and extraction was conducted for 10 hours, at which the weight and concentration of the cyclohexane carboxylic acid in the fermentation broth residue was 0.09g and 0.43 g / L respectively. The liquid in the extractor was decanted into a separation funnel and the aqueous and organic layers were separated. The top layer was dried of magnesium sulfate and evaporated under vacuum to provide a residue having a weight of 3.35 g. The aqueous bottom layer was extracted three times with 20 ml ethyl acetate each time. The combined extracts were dried over magnesium sulfate and evaporated under vacuum to provide a residue having a weight of 0.025 g.

[0066] Example 1 A - Esterification Reaction

[0067] The 3.35 g residue of the top layer of Example 1 was added to a 250 ml round bottom 3-neck flask along with 40 ml of absolute ethanol and 0.36 g of polymer catalyst (Amberlyst 17). The esterification reaction proceeded under the following conditions:

[0068] -90 g of molecular sieves and 150 ml of ethanol were added to a Soxhlet extractor;

[0069] -after 20 hours, the molecular sieves were discarded, and 90 g of fresh molecular sieves and 150 ml were added;

[0070] -after 29 hours, the molecular sieves were discarded, and 90 g of fresh molecular sieves and 150 ml were added; -after 44 hours, the molecular sieves were discarded, and 90 g of fresh molecular sieves and 150 ml were added;

[0071] -after 55 hours, the molecular sieves were discarded, and 90 g of fresh molecular sieves and 150 ml were added;

[0072] -after 68 hours, a sample was analyzed by gas chromatography.

[0073] The peak area percent of the esters was 68.7 percent cyclohexanoate, 11.3 percent crotonate, 16.4 percent benzoate, and 1.1 percent cyclohexenoate.

[0074] Comparative Example 2

[0075] A simulated fermentation broth (100 ml) containing 1 g / L cyclohexane carboxylic acid, 0.5 g / L benzoic acid, 0.01 g / L cyclohexene carboxylic acid, 0.06 g / L crotonic acid and 2 g / L acetic acid was subjected to was subjected to hydro-distillation (steam distillation). The simulated fermentation broth was prepared by dissolving 100 mg cyclohexane carboxylic acid, 50 mg benzoic acid, 10 mg cyclohexene carboxylic acid, 60 mg crotonic acid and 200 mg acetic acid in 100 ml of deionized water. The simulated fermentation broth was transferred to a heating vessel for hydro-distillation. The simulated broth was heated to 128°C and fractions were taken every 15 minutes until 9 distillation fractions were collected. The collective weight of the 9 distillate fractions was 73.1 g. The concentrations of cyclohexane carboxylic acid (1.23 g / L), 1-cyclohexene carboxylic acid (0.0081 g / L) and benzoic acid (0.19 g / L) in the distillation residue was determined by liquid chromatography. Comparative Example 2 demonstrates that cyclohexane carboxylic acid is more volatile than benzoic acid in hydro-distillation (steam distillation). Comparative Example 3

[0076] Carboxylic acids were added to a low cyclohexane carboxylic acid containing fermentation broth to bring the concentration of cyclohexane carboxylic acid to 0.58 g / L, benzoic acid to 0.55 g / L, cyclohexene carboxylic acid to 0.01 g / L, crotonic acid to 1.12 g / L, and acetic acid to 2 g / L, and was subject to hydro-distillation. In a 1-L Erlenmeyer flask, a first broth was prepared by adding a solution of cyclohexane carboxylic acid (0.5802 g), benzoic acid (0.6310 g), 1 -cyclohexene- 1 -carboxylic acid (7.9 mg), and acetic acid (2.0007 g) with stirring to 997 g of the low cyclohexane carboxylic acid containing fermentation broth. In a 2- L Erlenmeyer flask, a second broth was prepared by adding a solution of cyclohexane carboxylic acid (0.9858 g), benzoic acid (0.8565 g), 1 -cyclohexene- 1 -carboxylic acid (9.5 mg), and acetic acid (3.3998 g) with stirring to 1,700 g of the low cyclohexane carboxylic acid containing fermentation broth. The first and second broths were combined for a total 2.7 L of broth. The simulated fermentation broth was transferred to a heating vessel for hydrodistillation. The pH of the combined first and second broths was 6.6. The pH of the combined first and second broths was adjusted to 2.5 with phosphoric acid. The biomass was removed from the broth by centrifugation at 4500 RPM and 20°C for 30 minutes. The 2.7 L broth containing the organic acids was first extracted with 500 ml of ethyl acetate. Following the first extraction step, the aqueous and organic solvent layers were separated, the top organic solvent layer was washed with 30 ml brine solution, dried over sodium sulfate, and concentrated under vacuum to provide a residue (5.6742 g). The aqueous layer from the first extraction was extracted with ethyl acetate (500 ml). Following the second extraction step, the aqueous and organic solvent layers were separated, the top organic layer was washed with brine solution (30 ml), dried over sodium sulfate and concentrated under vacuum to provide residue (2.3409 g). The aqueous layer from the second extraction was extracted with ethyl acetate (500 ml). Following the third extraction step, the aqueous and organic solvent layers were separated, the top organic layer was washed with brine solution (30 ml), dried over sodium sulfate and concentrated under vacuum to provide residue (1.1959 g). The pH of the residue was 2.8 and was adjusted to 4.5 with 10% sodium carbonate (5.6 g). The mixture was subjected to hydrodistillation giving 245 g distillate. The distillate (245 g) was extracted with 100 ml ethyl acetate. Following the first extraction step, the aqueous and organic solvent layers were separated, the top organic solvent layer was washed with 30 ml brine solution, dried over sodium sulfate, and concentrated under vacuum to provide a residue. The aqueous layer was extracted twice with ethyl acetate, 100 ml each. For each extraction, the layers are separated. The top organic layer was washed with 30 ml of brine solution, dried over sodium sulfate, and concentrated under vacuum. The three residues, 3.08 g, were combined.

[0077] Comparative Example 3 A - Esterification Reaction

[0078] A sample of the broth residue from Comparative Example 3 obtained through the first ethyl acetate extraction step and which did not undergo the further hydro-distillation or second ethyl acetate extraction steps was used in an esterification reaction with ethanol to determine the presence of cyclohexane carboxylic acid. In a 250 ml round bottom flask, 2.34 g of the broth residue, 20 ml of absolute ethanol, and 0.36 g Amberlyst 17 polymer catalyst were added. 90 g of molecular sieves and 150 ml ethanol were added to a Soxhlet extractor. The round bottom flask was heated to reflux condition. After 24 hours, the heater was turned off and a sample was analyzed by gas chromatography. The esterification product cyclohexanoate was detected at 23%.

[0079] Comparative Example 3B - Esterification Reaction

[0080] A sample of the broth residue from Comparative Example 3 obtained through the first ethyl acetate extraction step and which did not undergo the further hydro-distillation or second ethyl acetate extraction steps was used in an esterification reaction with ethanol to determine the presence of cyclohexane carboxylic acid. In a 250 ml round bottom flask, 1.20 g of the broth residue, 40 ml of absolute ethanol, and 0.24 g Amberlyst 17 polymer catalyst were added. 90 g of molecular sieves and 150 ml ethanol were added to a Soxhlet extractor. The round bottom flask was heated to reflux condition. After 24 hours, the heater was turned off and a sample was analyzed by gas chromatography. The esterification product cyclohexanoate was detected at 6%.

[0081] Comparative Example 3C-Esterification Reaction

[0082] A sample of the broth residue from Comparative Example 3 that was prepared by both the first and second ethyl acetate extraction steps and the hydro-distillation step was used in an esterification reaction. In a 250 ml round bottom flask, 3.08 g of the broth residue, 40 ml of absolute ethanol, and 0.36 g Amberlyst 17 polymer catalyst were added. 90 g of molecular sieves and 150 ml ethanol were added to a Soxhlet extractor. The round bottom flask was heated to reflux condition. After 24 hours, the molecular sieves were discarded. 90 g of fresh molecular sieves and 150 ml of ethanol were added to the flask and heating was resumed. After another 30 hours of heating and sample was taken and analyzed by gas chromatography. The peak area percent was 75 percent for cyclohexanoate, 0.6 percent for cyclohexeneoate, 4 percent for benzoate, 18 percent for crotonate, and 10 percent for acetate.

[0083] Comparative Example 4

[0084] A fermentation broth containing cyclohexane carboxylic acid (0.58 g / L), benzoic acid (0.63) g / L, cyclohexene carboxylic acid (0.014 g / L), crotonic acid (0.43 g / L), and acetic acid (2 g / L) was subject to hydro-distillation and liquid-liquid extraction. The pH of the fermentation broth was 7.36 and was adjusted to 2.5 with a solution of 40% phosphoric acid (53 g). The biomass was removed from the broth by centrifugation at 4500 RPM and 20°C for 30 minutes. The fermentation broth containing the organic acids was extracted with 500 ml of ethyl acetate. Following the first extraction step, the aqueous and organic solvent layers were separated, the top organic solvent layer was washed with 30 ml brine solution, dried over sodium sulfate, and concentrated under vacuum to provide a residue 1. The aqueous layer from the first extraction step was extracted with 500 ml ethyl acetate. Following the second extraction step, the aqueous and organic solvent layers were separated, the top organic solvent layer was washed with 30 ml brine solution, dried over sodium sulfate, and concentrated under vacuum to provide a residue 2. The aqueous layer from the second extraction step was extracted with 500 ml ethyl acetate. Following the third extraction step, the aqueous and organic solvent layers were separated, the top organic solvent layer was washed with 30 ml brine solution, dried over sodium sulfate, and concentrated under vacuum to provide a residue 1. Residues 1- 3 (6.25 g) were combined and suspended in 285 ml of deionized water in a 500 ml round bottom flask. The pH of the suspended residue was 2.65, and was adjusted to 4.5 with 10% sodium carbonate (9g). The pH adjusted solution was subjected to hydro-distillation. The distillation fractions were collected and subject to another round of liquid-liquid extraction. The collected distillate (293 g) was extracted with 100 ml ethyl acetate. Following the fourth extraction step, the aqueous and organic solvent layers were separated, the top organic solvent layer was washed with 30 ml brine solution, dried over sodium sulfate, and concentrated under vacuum to provide a residue 4. The aqueous layer from the fourth extraction step was extracted with 100 ml ethyl acetate. Following the fifth extraction step, the aqueous and organic solvent layers were separated, the top organic solvent layer was washed with 30 ml brine solution, dried over sodium sulfate, and concentrated under vacuum to provide a residue 5. The aqueous layer from the fifth extraction step was extracted with 100 ml ethyl acetate. Following the sixth extraction step, the aqueous and organic solvent layers were separated, the top organic solvent layer was washed with 30 ml brine solution, dried over sodium sulfate, and concentrated under vacuum to provide a residue 6. Comparative Example 4A-Esterification Reaction

[0085] Residues 4-6 were combined and was used in an esterification reaction. In a 250 ml round bottom flask, combined residues 4-6 (2.34 g), 40 ml of absolute ethanol, and 0.36 g Amberlyst 17 polymer catalyst were added. 90 g of molecular sieves and 150 ml ethanol were added to a Soxhlet extractor. The round bottom flask was heated to reflux condition. After 20 hours, the molecular sieves were discarded. 90 g of fresh molecular sieves and 150 ml of ethanol were added to the flask and heating was resumed. After another 24 hours, the molecular sieves were discarded. 90 g of fresh molecular sieves and 150 ml of ethanol were added to the flask and heating was resumed. After another 24 hours of heating a sample was taken and analyzed by gas chromatography. The peak area percent was 79 percent for cyclohexanoate, 0.6 percent for cyclohexeneoate, 2 percent for benzoate, 10 percent for crotonate, and 3 percent for acetate.

[0086] Comparative Example 5

[0087] A simulated fermentation broth containing 0.58 g / L cyclohexane carboxylic acid, 0.63 g / L benzoic acid, 0.014 g / L cyclohexene carboxylic acid, 1.12 g / L crotonic acid and 2 g / L acetic acid was prepared. The simulated fermentation broth was prepared by dissolving 1.5958 g cyclohexane carboxylic acid, 1.7312 g benzoic acid, 21.175 mg cyclohexene carboxylic acid, and 5.5137 g acetic acid in 2.75 kg of a fermentation broth. The pH was 5.95 and was adjusted to 2.48 with a phosphoric acid solution (50 g). The biomass was removed by centrifugation at 4,5000 RPM at 20°C for 30 minutes. The carboxylic acid containing fermentation broth was extracted three times with ethyl acetate, 500 ml each time. After separating the aqueous and organic solvent layers, the top organic solvent layers were combined, washed with brine (100 ml), dried over sodium sulfate and concentrated under vacuum evaporation to form a residue. The residue (11.5 g) was suspended in 250 ml of deionized water in a 500 ml round bottom flask. The pH was 2.55 and was adjusted to 4.5 with 10% sodium carbonate solutions (16.3 g). Simultaneous distillation extraction was conducted as follows:

[0088] Extraction 1 : In a 250-ml round bottom flask, 150 ml of ethyl acetate was added. The extraction was run for 5 hours. The extract was dried over sodium sulfate and concentrated by vacuum evaporation providing a residue (2.4 g);

[0089] Extraction 2: In a 250-ml round bottom flask, 150 ml of ethyl acetate was added. The extraction was run for 8 hours. The extract was dried over sodium sulfate and concentrated by vacuum evaporation providing a residue (1.6 g);

[0090] Extraction 3: In a 250-ml round bottom flask, 150 ml of ethyl acetate was added. The extraction was run for 5 hours. The extract was dried over sodium sulfate and concentrated by vacuum evaporation providing a residue (0.4 g);

[0091] Extraction 4: In a 250-ml round bottom flask, 150 ml of ethyl acetate was added. The extraction was run for 8 hours. The extract was dried over sodium sulfate and concentrated by vacuum evaporation providing a residue (0.3 g);

[0092] Extraction 5: In a 250-ml round bottom flask, 150 ml of ethyl acetate was added. The extraction was run for 24 hours. The extract was dried over sodium sulfate and concentrated by vacuum evaporation providing a residue (0.4 g).

[0093] Methyl tert-butyl ether (MtBE) solvent (80 ml) was added to the combined liquid residues and washed with 3 ml brine. The top layer was dried over sodium sulfate and concentrated by vacuum evaporation to provide a residue (3.50 g).

[0094] Comparative Example 5 A - Esterification Reaction

[0095] The combined liquid residues from Comparative Example 5 was used in an esterification reaction. In a 250 ml round bottom flask, the combined liquid residues (3.50 g), 40 ml of absolute ethanol, and 0.36 g Amberlyst 17 polymer catalyst were added. 90 g of molecular sieves and 150 ml ethanol were added to a Soxhlet extractor. The round bottom flask was heated to reflux condition. After 15 hours, the molecular sieves were discarded. 90 g of fresh molecular sieves and 50 ml of ethanol were added to the flask and heating was resumed. After another 8 hours, the molecular sieves were discarded. 90 g of fresh molecular sieves and 50 ml of ethanol were added to the flask and heating was resumed. After another 15 hours, the molecular sieves were discarded. 90 g of fresh molecular sieves and 50 ml of ethanol were added to the flask and heating was resumed. After another 8 hours of heating a sample was taken and analyzed by gas chromatography and no carboxylic acids remained. The peak area percent was 67.2 percent for cyclohexanoate, 0.7 percent for cyclohexenoate, 4.6 percent for benzoate, 27.5 percent for crotonate, and 3 percent for acetate. The results of Example 1 and Comparative Examples 2-5 are summarized in Table 1 below:

[0096] Table 1 CE = continuous extraction

[0097] HD = hydro-distillation

[0098] SDE = simultaneous distillation extraction

[0099] CHC = cyclohexane carboxylic acid d-CHC =delta-cyclohexene carboxylic acid (also, 1 -cyclohexene- 1 -carboxylic acid)

[0100] Bz = benzoic acid

[0101] Cr = crotonic acid

[0102] Comparative Example 6A

[0103] A study was conducted to determine the effect of pH on the extraction of carboxylic acids from a fermentation broth containing the carboxylic acids cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid. 250 g of fermentation broth containing cyclohexane carboxylic acid having a pH 6.91 was evaluated. 92 g of trisodium citrate solution was added to the fermentation broth in a round bottom flask to increase the pH of the fermentation broth to 7.40. Extraction was conducted as follows:

[0104] -Extraction solvent ethyl acetate was added to the extractor;

[0105] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0106] -After 1 hour, the pH of the fermentation broth was 6.71;

[0107] -After two hours, the pH was 6.63 and extraction was stopped.

[0108] A sample of the fermentation broth was taken and analyzed by liquid chromatography for the presence of the carboxylic acids. All carboxylic acids were detected in the sample of the broth: cyclohexanecarboxylic acid, 1-cyclohexene-l-carboxylic acid, benzoic acid, crotonic acid, and acetic acid remained in the boiling round bottom flask. These results indicate that the carboxylic acids cannot be extracted from the fermentation broth at a pH of 6 or greater. Comparative Example 6B

[0109] A study was conducted to determine the effect of pH 6 on the extraction of carboxylic acids from a fermentation broth containing the carboxylic acids cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid. 250 g of fermentation broth containing cyclohexane carboxylic acid having a pH 6 was evaluated. The fermentation broth of Example 6A was cooled and 2.6 g of citric acid solution was added to the fermentation broth in a round bottom flask to decrease the pH of the fermentation broth to 6. Extraction was conducted as follows:

[0110] -Extraction solvent ethyl acetate (190 ml) was added to the extractor;

[0111] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0112] -After 1 hour, the pH of the fermentation broth was 6.0;

[0113] -After two hours, the pH was 6.01 and extraction was stopped.

[0114] A sample of the broth was taken and analyzed by liquid chromatography for the presence of the carboxylic acids. About 2% of the carboxylic acid cyclohexane carboxylic acid was expected in the extract. Most of the cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid remained in the boiling round bottom flask. These results indicate that very little carboxylic acids are extracted from the fermentation broth at a pH of 6.

[0115] Comparative Example 6C

[0116] A study was conducted to determine the effect of pH 5.5 on the extraction of carboxylic acids from a fermentation broth containing the carboxylic acids cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid. The fermentation broth of Example 6B was cooled and 5.3 g of saturated citric acid solution was added to the fermentation broth in a round bottom flask to increase the pH of the fermentation broth to 5.5. Extraction was conducted as follows:

[0117] -Extraction solvent ethyl acetate (190 ml) was added to the extractor;

[0118] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0119] -After 1 hour, the pH of the fermentation broth was 5.51;

[0120] -After two hours, the pH was 5.53 and extraction was stopped.

[0121] A sample of the broth was taken and analyzed by liquid chromatography for the presence of the carboxylic acids. About 20% of cyclohexane carboxylic acid and 15% crotonic acid were expected in the extract. Most of the cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid remained in the boiling round bottom flask. These results indicate that only a small portion of the carboxylic acids are extracted from the fermentation broth at a pH of 5.5.

[0122] Example 6D

[0123] A study was conducted to determine the effect of pH less than 5 on the extraction of carboxylic acids from a fermentation broth containing the carboxylic acids cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid. The fermentation broth of Example 6C was cooled and 19 g of saturated citric acid solution and 60 g of citric acid were added to the fermentation broth in a round bottom flask to increase the pH of the fermentation broth to 3.22. Extraction was conducted as follows:

[0124] -Extraction solvent ethyl acetate (190 ml) was added to the extractor;

[0125] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0126] -After 1 hour, the pH of the fermentation broth was 3.21;

[0127] -After two hours, the pH was 3.21 and extraction was stopped. A sample of the broth was taken and analyzed by liquid chromatography for the presence of the carboxylic acids. No cyclohexane carboxylic acid remained in the flask. These results indicate that all carboxylic acids are extracted from the fermentation broth at a pH of 3.1.

[0128] Example 7

[0129] A study was conducted to determine the effect of pH of about 2 on the extraction of carboxylic acids from a fermentation broth containing the carboxylic acids cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid. 250 g of fermentation broth containing 4.91 g / L of cyclohexane carboxylic acid having a pH 6.91 was evaluated. The pH was adjusted to 4.20 by the addition of saturated citric acid solution (16.8 g). The pH was subsequently adjusted to 2.10 by the addition of 40% phosphoric acid (26.5 g). Extraction was conducted as follows:

[0130] -Extraction solvent ethyl acetate was added to the extractor;

[0131] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0132] -After 1 hour, the pH of the fermentation broth was 2.13;

[0133] -After two hours, the pH was 2.13 and extraction was stopped.

[0134] A sample of the broth was taken and analyzed by liquid chromatography for the presence of the carboxylic acids. 21% of the cyclohexane carboxylic acid, 44% of the cyclohexene carboxylic acid, 31% of the benzoic acid and 46% of the crotonic acid remained in the boiling flask.

[0135] Example 8

[0136] A study was conducted to extract carboxylic acids from a fermentation broth containing the carboxylic acids cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid, and to use an extracted and purified carboxylic acid in a downstream esterification reaction to prepare a desired esterification reaction product. 250 g of fermentation broth containing cyclohexane carboxylic acid having a pH 6.91 was evaluated. 8 g of citric acid was added to the fermentation broth in a round bottom flask with stirring to decrease the pH of the fermentation broth to 4.29. The mixture was transferred a 3 -neck 500- ml round bottom flask for extraction. The pH of the mixture was adjusted to 4.2 with 1.5 g of citric acid. Extraction 1 was conducted as follows:

[0137] -Extraction solvent ethyl acetate (190 ml )was added to the extractor;

[0138] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0139] -After 3 hours, the pH of the fermentation broth was 4.33;

[0140] -After 4 hours, the pH of the fermentation broth was 4.35;

[0141] -After 5 hours, the pH was 4.35 and extraction was stopped.

[0142] The mixture in the extractor was added to a separatory funnel and the aqueous and organic solvent extraction layers were separated. The lower aqueous layer was returned to the boiling flask, the pH was 4.25 and was adjusted to 4.20 with 2.3 g of citric acid solution. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 8-1 (3.4640 g).190 ml of fresh ethyl acetate was added to the extractor and extraction was resumed. After 3 hours, the pH was 4.26 and no cyclohexane carboxylic acid remained in the boiling flask. The mixture in the extractor was transferred to a separatory funnel and the aqueous and organic solvent layers were separated. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate, and concentrated by vacuum evaporation to provide a residue 8-2 (0.1320 g). Residues 8-1 and 8-2 were combined with 100 ml of deionized water.3.7 g of citric was added to the mixture with stirring to dissolve. The pH of the mixture was 2.10 and was adjusted to 4.18 by the slow addition of saturated trisodium citrate (21 g). An additional 160 g of deionized water was added to the mixture and the resulting pH was 4.20. A sample of the mixture was taken and analyzed by liquid chromatography, which results show the following composition of acids: 3.93 g / L cyclohexane carboxylic acid, 0.044 g / L cyclohexene carboxylic acid, 1.80 g / L benzoic acid, and 2.31 g / L crotonic acid.

[0143] Extraction 2 was conducted on the re-solvated residue mixture obtained from Extraction 1 as follows:

[0144] -Extraction solvent ethyl acetate (190 ml )was added to the extractor;

[0145] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0146] -After 3 hours, the pH of the fermentation broth was 4.30;

[0147] -After 4 hours, the pH of the fermentation broth was 4.32;

[0148] -After 5 hours, the pH was 4.33 and extraction was stopped.

[0149] The mixture in the extractor was added to a separatory funnel and the aqueous and organic solvent extraction layers were separated. The lower aqueous layer was returned to the boiling flask, the pH was 4.38 and was adjusted to 4.20 with 1.8 g of citric acid solution. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 8-3 (2.1521 g).190 ml of fresh ethyl acetate was added to the extractor and extraction was resumed. After 2 hours, the pH was 4.22 and no cyclohexane carboxylic acid remained in the boiling flask. The mixture in the extractor was transferred to a separatory funnel and the aqueous and organic solvent layers were separated. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate, and concentrated by vacuum evaporation to provide a residue 8-4 (0.3024 g). Residues 8-3 and 8-4 were combined with 100 ml of deionized water. 2.9 g of citric was added to the mixture with stirring to dissolve. The pH of the mixture was 2.10 and was adjusted to 4.21 by the slow addition of saturated trisodium citrate (14 g). An additional 128 g of deionized water was added to the mixture and the resulting pH was 4.20. A sample of the mixture was taken and analyzed by liquid chromatography, which results show the following composition of acids: 4.68 g / L cyclohexane carboxylic acid, 0.037 g / L cyclohexene carboxylic acid, 0.49 g / L benzoic acid, and 1.68 g / L crotonic acid.

[0150] Extraction 3 was conducted on the re-solvated residue mixture obtained from Extraction 2 as follows:

[0151] -Extraction solvent ethyl acetate (190 ml )was added to the extractor;

[0152] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0153] -After 3 hours, the pH of the fermentation broth was 4.25;

[0154] -After 4 hours, the pH of the fermentation broth was 4.29 and extraction was stopped.

[0155] The mixture in the extractor was added to a separatory funnel and the aqueous and organic solvent extraction layers were separated. The lower aqueous layer was returned to the boiling flask, the pH was adjusted to 4.20 with 1.0 g of citric acid solution. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 8-5 (1.8244 g). 190 ml of fresh ethyl acetate was added to the extractor and extraction was resumed. After 2 hours, the pH was 4.18 and no cyclohexane carboxylic acid remained in the boiling flask and the extraction was stopped. The mixture in the extractor was transferred to a separatory funnel and the aqueous and organic solvent layers were separated. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 8-6 (0.1752 g). Residues 8-5 and 8-6 were combined. A portion of the residue was resolvated in deionized water (pH 4.2). A sample of the resolvated combined residue was taken and analyzed by liquid chromatography, which results show the following composition of acids: 4.95 g / L cyclohexane carboxylic acid, 0.028 g / L cyclohexene carboxylic acid, 0.10 g / L benzoic acid, and 1.05 g / L crotonic acid. Example 8A - Esterification

[0156] Esterification Reaction

[0157] The 2.00 g residue of the combined residues 8-5 and 8-6 obtained in Example 8 was added to a 100 ml round bottom 3-neck flask along with 60 ml of absolute ethanol and 0.35 g of polymer catalyst (Amberlyst 17). The esterification reaction proceeded under the following conditions:

[0158] -15 g of molecular sieves was added to a 50-ml Soxhlet extractor and the flask was heated to reflux condition;

[0159] -after 24 hours, a sample was tested and 0% cyclohexane carboxylic acid, 0% cyclohexene carboxylic acid, 0% benzoic acid and 7.5% crotonic acid remained;

[0160] -after another 24 hours, a sample was tested and 0% cyclohexane carboxylic acid, 0% cyclohexene carboxylic acid, 0% benzoic acid and 7.5% crotonic acid remained;

[0161] -0.1 g of Amberlyst 17 was added and the heating was resumed;

[0162] -after another 24 hours, a sample was tested and 0% cyclohexane carboxylic acid, 0% cyclohexene carboxylic acid, 0% benzoic acid and 7.5% crotonic acid remained.

[0163] -A sample was analyzed by gas chromatography. The peak area percent of the esters was 79.5 percent cyclohexanoate, 12.9 percent crotonate, 0 percent benzoate, and 0 percent cyclohexenoate.

[0164] Example 9 A

[0165] A study was conducted to extract carboxylic acids from a fermentation broth containing the carboxylic acids cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid, and to use an extracted and purified carboxylic acid in a downstream esterification reaction to prepare a desired esterification reaction product by an extraction method that uses a liquid-liquid extraction unit without a distillation column. 250 g of fermentation broth containing 4.91 g / L of cyclohexane carboxylic acid having a pH 6.91 was added to a 3-neck 500-ml round bottom flask for extraction. 18 g of citric acid was added with stirring to dissolve. The pH of the mixture was adjusted to 4.2 with 38 g of saturated trisodium citrate solution. Extraction 1 was conducted as follows:

[0166] -Extraction solvent ethyl acetate (190 ml )was added to the extractor;

[0167] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0168] -After 3 hours, the pH of the fermentation broth was 4.23 and extraction was stopped.

[0169] The mixture in the extractor was added to a separatory funnel and the aqueous and organic solvent extraction layers were separated. The lower aqueous layer was returned to the boiling flask, the pH was 4.26 and was used for further extraction. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 9-1 (2.88 g).190 ml of fresh ethyl acetate was added to the extractor and extraction was resumed. After 2 hours, the pH was 4.26 and no cyclohexane carboxylic acid remained in the boiling flask. The mixture in the extractor was transferred to a separatory funnel and the aqueous and organic solvent layers were separated. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 9-2 (0.9810 g). Residues 9-1 and 9-2 were combined with 100 ml of deionized water. 18 g of citric was added to the mixture with stirring to dissolve. The pH of the mixture was 1.42 and was adjusted to 4.197 by the slow addition of saturated trisodium citrate (87 g). An additional 41 g of deionized water was added to the mixture and the resulting pH was 4.20.

[0170] Extraction 2 was conducted on the aqueous layer obtained from Extraction 1 as follows: -Extraction solvent ethyl acetate (190 ml )was added to the extractor; -The round botom flask containing the fermentation broth was heated to reflux condition;

[0171] -After 2 hours, the pH of the fermentation broth was 4.249;

[0172] -After 3 hours, the pH of the fermentation broth was 4.174 and extraction was stopped. The mixture in the extractor was added to a separatory funnel and the aqueous and organic solvent extraction layers were separated. The lower aqueous layer was returned to the boiling flask, the pH was 4.265. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 9-3 (2.1220 g). 190 ml of fresh ethyl acetate was added to the extractor and extraction was resumed. After 2 hours, the pH was 4.22 and no cyclohexane carboxylic acid remained in the boiling flask and the extracted was stopped. The mixture in the extractor was transferred to a separatory funnel and the aqueous and organic solvent layers were separated. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 9-4 (0.3517 g). Residues 9-3 and 9-4 were combined with 100 ml of deionized water. 9 g of citric was added to the mixture with stirring to dissolve. The pH of the mixture was 2.10 and was adjusted to 4.209 by the slow addition of saturated trisodium citrate (41.2 g). An additional 97 g of deionized water was added to the mixture and the resulting pH was 4.243.

[0173] Extraction 3 was conducted on the aqueous layer obtained from Extraction 2 as follows: -Extraction solvent ethyl acetate (190 ml ) was added to the extractor;

[0174] -The round botom flask containing the fermentation broth was heated to reflux condition;

[0175] -After 3 hours, the pH of the fermentation broth was 4.279;

[0176] -After 4 hours, the pH of the fermentation broth was 4.258 and extraction was stopped. The mixture in the extractor was added to a separatory funnel and the aqueous and organic solvent extraction layers were separated. The lower aqueous layer was returned to the boiling flask. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 9-5 (1.7671 g). 190 ml of fresh ethyl acetate was added to the extractor and extraction was resumed. After 2 hours, the pH was 4.289 and no cyclohexane carboxylic acid remained in the boiling flask and the extraction was stopped. The mixture in the extractor was transferred to a separatory funnel and the aqueous and organic solvent layers were separated. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 9-6 (0.2133 g). Residues 9-5 and 9-6 were combined with deionized water to re-solvate. Residues 9-5 and 9-6 were combined with 100 ml of deionized water. 9 g of citric was added to the mixture with stirring to dissolve. The pH of the mixture was 2.10 and was adjusted to 4.209 by the slow addition of saturated trisodium citrate (41.2 g). An additional 97 g of deionized water was added to the mixture and the resulting pH was 4.246. This re-solvated mixture was extracted 3 times with ethyl acetate, 200 ml each. The extract was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 9-7 (1.4352 g). In an esterification reaction, 1.44 g of residue 9-7, 60 ml absolute ethanol and 0.35 g of a polymer catalyst (Amberlyst 17) were added to a 3-neck, 100 -ml round bottom flask. 15 g of molecular sieves were added to a Soxhlet reactor. The round bottom flask was heated to reflux condition. After 48 hours, a sample was analyzed by gas chromatography. The peak area percent of the esters was 81.7 percent cyclohexanoate, 10.9 percent crotonate, 0 percent benzoate, 0 percent cyclohexenoate, and 6.5% ethyl butyrate.

[0177] Example 9B

[0178] A study was conducted to extract carboxylic acids from a fermentation broth containing the carboxylic acids cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylic acid, benzoic acid, crotonic acid, and acetic acid, and to use an extracted and purified carboxylic acid in a downstream esterification reaction to prepare a desired esterification reaction product by an extraction method that uses a distillation column in combination with a liquid-liquid extraction unit. 250 g of fermentation broth containing 4.91 g / L of cyclohexane carboxylic acid having a pH 6.803 was added to transferred a 3-neck 500-ml round bottom flask for extraction. The pH of the mixture was adjusted to 3.561 by the addition of 18 g of citric acid with stirring. The pH of the mixture was adjusted to 4.198 with 35.3 g trisodium citrate solution. Extraction 1 was conducted as follows:

[0179] -Extraction solvent ethyl acetate (190 ml ) was added to the extractor;

[0180] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0181] -After 3 hours, the pH of the fermentation broth was 4.199 and extraction was stopped.

[0182] The mixture in the extractor was added to a separatory funnel and the aqueous and organic solvent extraction layers were separated. The lower aqueous layer was returned to the boiling flask, the pH was 4.199 and was used for further extraction. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate, and concentrated by vacuum evaporation to provide a residue 9-9 (2.50 g). Extraction 2 was conducted on the aqueous layer obtained from Extraction 1 as follows:

[0183] -Extraction solvent ethyl acetate (190 ml )was added to the extractor;

[0184] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0185] -After 2 hours, the pH of the fermentation broth was 4.187;

[0186] -After 3 hours, the pH of the fermentation broth was 4.152;

[0187] -After 4 hours, the pH of the fermentation broth was 4.153 and extraction was stopped. The mixture in the extractor was added to a separatory funnel and the aqueous and organic solvent extraction layers were separated. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate, and concentrated by vacuum evaporation to provide a residue 9-10 (0.5497 g). Residues 9-9 and 9-10 were combined with 100 ml of deionized water. 18 g of citric was added to the mixture with stirring to dissolve. The pH of the mixture was 1.589 and was adjusted to 4.200 by the slow addition of saturated trisodium citrate (82 g). An additional 47 g of deionized water was added to the mixture. Extraction 3 was conducted on the aqueous layer obtained from Extraction 2 as follows:

[0188] -190 ml of fresh ethyl acetate was added to the extractor and extraction was resumed.

[0189] -After 2 hours, the pH of the fermentation broth was 4.209;

[0190] -After 3 hours, the pH of the fermentation broth was 4.232;

[0191] After 4 hours, the pH of the fermentation broth was 4.219 and the extraction was stopped.

[0192] The mixture in the extractor was transferred to a separatory funnel and the aqueous and organic solvent layers were separated. The lower aqueous layer having a pH of 4.219 was returned to the flask for further extraction. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 9-11 (1.9955 g). Extraction 4 was conducted on the aqueous layer obtained from Extraction 3 as follows:

[0193] -Extraction solvent ethyl acetate (190 ml ) was added to the extractor;

[0194] -The round bottom flask containing the fermentation broth was heated to reflux condition;

[0195] -After 2 hours, the pH of the fermentation broth was 4.226 and extraction was stopped.

[0196] The mixture in the extractor was added to a separatory funnel and the aqueous and organic solvent extraction layers were separated. The top organic solvent layer was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 9-12 (0.1029 g). Residues 9-11 and 9-12 were combined with deionized water to resolvate. Residues 9-11 and 9-12 were combined with 100 ml of deionized water. 9 g of citric was added to the mixture with stirring to dissolve. The pH of the mixture was adjusted to 4.174 by the slow addition of saturated trisodium citrate (38.6 g). An additional 102 g of deionized water was added to the mixture and the resulting pH was 4.231. This re-solvated mixture was extracted 3 times with ethyl acetate, 200 ml each. The extract was dried over sodium sulfate and magnesium sulfate and concentrated by vacuum evaporation to provide a residue 9-13 (2.0365 g). In an esterification reaction, 2.04 g of residue 9-13, 60 ml absolute ethanol and 0.35 g of a polymer catalyst (Amberlyst 17) were added to a 3 -neck, 100 -ml round bottom flask.

[0197] 15 g of molecular sieves were added to a Soxhlet reactor. The round bottom flask was heated to reflux condition. After 48 hours, a sample was analyzed by gas chromatography. The peak area percent of the esters was 81.3 percent cyclohexanoate, 10.3 percent crotonate, 0 percent benzoate, 0 percent cyclohexenoate, and 7.3% ethyl butyrate. Table 2 While the method of separating compounds been described in connection with various embodiments, it is to be understood that other similar embodiments may be used or modifications and additions may be made to the described embodiments for performing the same function. Furthermore, the various illustrative embodiments may be combined to produce the desired results. Therefore, the disclosed methods, uses, compositions, and consumables should not be limited to any single embodiment, but rather construed in breadth and scope in accordance with the recitation of the appended claims. It will be understood that the embodiments described herein are merely exemplary, and that one skilled in the art may make variations and modifications without departing from the spirit and scope of the invention. All such variations and modifications are intended to be included within the scope of the invention as described hereinabove. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments of the invention may be combined to provide the desired result.

Claims

CLAIMS1. A method for extracting a cyclohexane carboxylic acid from a blend of carboxylic acid compounds comprising the cyclohexane carboxylic acid and carboxylic acid impurities present in an aqueous fermentation broth, the method comprising: providing a fermentation broth comprising the blend of carboxylic acids; adjusting the pH of the aqueous fermentation broth containing the blend of carboxylic acids to a more acidic pH; heating the aqueous fermentation broth containing the blend of carboxylic acid compounds to create water vapor from the water in the aqueous fermentation broth; providing an organic extraction solvent having a density less than the density of water; condensing the water vapor into condensed water droplets containing cyclohexane carboxylic acid; extracting at least a portion of the cyclohexane carboxylic acid from the condensed water droplets by contacting the condensed water vapor droplets with the organic extraction solvent; and separating the organic extraction solvent layer containing the cyclohexane carboxylic acid from the aqueous layer containing the carboxylic acid impurities.

2. The method according to claim 1, wherein the blend of carboxylic acid compounds present in the fermentation broth comprises a blend of aromatic carboxylic acids and aliphatic carboxylic acids.

3. The method according to claim 2, wherein (a) the aromatic carboxylic acids contained in the fermentation broth comprise cyclohexane carboxylic acid, 1 -cyclohexene- 1 -carboxylicacid, and benzoic acid, and (b) wherein the aliphatic carboxylic acids contained in the fermentation broth comprise crotonic acid and acetic acid.

4. The method according to claim 3, wherein the fermentation broth comprises from 0.1 weight percent to 0.8 weight percent cyclohexane carboxylic acid, from 0.003 weight percent to 0.02 weight percent 1-cyclohexene-l-carboxylic acid, from 0.2 weight percent to 1.2 weight percent benzoic acid, from 0.3 weight percent to 0.7 weight percent crotonic acid, and from 2 weight percent to 3.2 weight percent acetic acid.

5. The method according to claim 1, wherein the organic extraction solvent has a density less than 1 g / ml.

6. The method according to claim 1, wherein the organic extraction solvent has a density less than 0.990 g / ml, or 0.985 g / ml, or 0.980 g / ml, or 0.975 g / ml, or 0.970 g / ml, or 0.970 g / ml, or 0.965 g / ml, or 0.960 g / ml, or 0.955 g / ml, or 0.950 g / ml, or 0.945 g / ml, or 0.940 g / ml, or 0.935 g / ml, or 0.930 g / ml, or 0.925 g / ml, or 0.920 g / ml, or 0.915 g / ml, or 0.910 g / ml, or 0.905 g / ml, or 0.900 g / ml.

7. The method according to claim 6, wherein the organic extraction solvent is selected from the group consisting of diethyl ether, ethyl acetate, hexane, t-butyl methyl ether, toluene, and mixtures thereof.

8. The method according to claim 6, wherein the pH of the fermentation broth is adjusted to a pH in the range of 4 to 5.

9. The method according to claim 1, wherein 90 weight percent or greater, or 91 weight percent or greater, or 92 weight percent or greater, or 93 weight percent or greater, or 94 weight percent or greater, or 95 weight percent or greater, or 96 weight percent or greater, or 97 weight percent or greater, or 98 weight percent or greater, or 99 weight percent or greater, or 99.1 weight percent or greater, or 99.2 weight percent or greater, or 99.3 weight percent or greater, or 99.4 weight percent or greater, or 99.5 weight percent or greater, or 99.6 weight percent or greater, or 99.7 weight percent or greater, or 99.8 weight percent, or greater, or 99.9 weight percent or greater, 100 weight percent, of the cyclohexane carboxylic acid contained in the fermentation broth is extracted.

10. The method according to claim 9, wherein 50 weight percent or greater, or 55 weight percent or greater, or 60 weight percent or greater, or 65 weight percent or greater, or 70 weight percent or greater, or 75 weight percent or greater, or 80 weight percent or greater, or 85 weight percent or greater, or 90 weight percent or greater, or 95 weight percent or greater, of the 1- cyclohexene carboxylic acid contained in the fermentation broth remains in the separated aqueous layer.

11. The method according to claim 9, wherein 90 weight percent or greater, or 91 weight percent or greater, or 92 weight percent or greater, or 93 weight percent or greater, or 94 weight percent or greater, or 95 weight percent or greater, or 96 weight percent or greater, or 97 weight percent or greater, or 98 weight percent or greater, or 99 weight percent or greater, or 99.1 weight percent or greater, or 99.2 weight percent or greater, or 99.3 weight percent or greater, or 99.4 weight percent or greater, or 99.5 weight percent or greater, or 99.6 weight percent or greater, or 99.7 weight percent or greater, or 99.8 weight percent, or greater, or 99.9 weight percent or greater, 100 weight percent, of the benzoic acid contained in the fermentation broth remains in the separated aqueous layer.

12. The method according to claim 9, wherein 50 weight percent or greater, or 55 weight percent or greater, or 60 weight percent or greater, or 65 weight percent or greater, or 70 weight percent or greater, or 75 weight percent or greater, or 80 weight percent or greater, or 85 weight percent or greater, or 90 weight percent or greater, or 95 weight percent or greater, of the crotonic acid contained in the fermentation broth remains in the separated aqueous layer.

13. The method according to claim 1, comprising the step of removing biomass from the fermentation broth before the step of heating the aqueous fermentation broth containing the blend of carboxylic acids.

14. The method according to claim 13, wherein the step of removing the biomass from the fermentation broth before the step of heating the aqueous fermentation broth containing the blend of carboxylic acids comprises filtering the fermentation broth.

15. The method according to claim 14, wherein the step of filtering the fermentation broth is conducted for a period of time from 5 to 20 hours.

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