CA1192141A - Concentration of organic chemicals from dilute aqueous solutions - Google Patents
Concentration of organic chemicals from dilute aqueous solutionsInfo
- Publication number
- CA1192141A CA1192141A CA000414773A CA414773A CA1192141A CA 1192141 A CA1192141 A CA 1192141A CA 000414773 A CA000414773 A CA 000414773A CA 414773 A CA414773 A CA 414773A CA 1192141 A CA1192141 A CA 1192141A
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- Prior art keywords
- organic compound
- carbon
- solvent
- volatile solvent
- column
- Prior art date
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P7/00—Preparation of oxygen-containing organic compounds
- C12P7/02—Preparation of oxygen-containing organic compounds containing a hydroxy group
- C12P7/04—Preparation of oxygen-containing organic compounds containing a hydroxy group acyclic
- C12P7/06—Ethanol, i.e. non-beverage
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C59/00—Compounds having carboxyl groups bound to acyclic carbon atoms and containing any of the groups OH, O—metal, —CHO, keto, ether, groups, groups, or groups
- C07C59/01—Saturated compounds having only one carboxyl group and containing hydroxy or O-metal groups
- C07C59/08—Lactic acid
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P7/00—Preparation of oxygen-containing organic compounds
- C12P7/02—Preparation of oxygen-containing organic compounds containing a hydroxy group
- C12P7/04—Preparation of oxygen-containing organic compounds containing a hydroxy group acyclic
- C12P7/16—Butanols
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P7/00—Preparation of oxygen-containing organic compounds
- C12P7/40—Preparation of oxygen-containing organic compounds containing a carboxyl group including Peroxycarboxylic acids
- C12P7/54—Acetic acid
-
- C—CHEMISTRY; METALLURGY
- C12—BIOCHEMISTRY; BEER; SPIRITS; WINE; VINEGAR; MICROBIOLOGY; ENZYMOLOGY; MUTATION OR GENETIC ENGINEERING
- C12P—FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE
- C12P7/00—Preparation of oxygen-containing organic compounds
- C12P7/40—Preparation of oxygen-containing organic compounds containing a carboxyl group including Peroxycarboxylic acids
- C12P7/56—Lactic acid
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E50/00—Technologies for the production of fuel of non-fossil origin
- Y02E50/10—Biofuels, e.g. bio-diesel
Abstract
ABSTRACT
A dilute aqueous solution of an organic compound is concentrated by adsorbing the compound on an adsorbent carbon bed and eluting the compound from the carbon by applying vapors of a volatile solvent to the bed maintained at or slightly below the condensation temperature of the solvent, at a rate of less than about one half bed volume per hour, until the solvent is detected in the eluate. The elution is then continued until about one half additional bed volume of eluate is collected which contains a concentrated aqueous solution of the compound in the solvent. Solvent is then evaporated to obtain an aqueous solution of the compound containing at least 30% of the compound by weight.
A dilute aqueous solution of an organic compound is concentrated by adsorbing the compound on an adsorbent carbon bed and eluting the compound from the carbon by applying vapors of a volatile solvent to the bed maintained at or slightly below the condensation temperature of the solvent, at a rate of less than about one half bed volume per hour, until the solvent is detected in the eluate. The elution is then continued until about one half additional bed volume of eluate is collected which contains a concentrated aqueous solution of the compound in the solvent. Solvent is then evaporated to obtain an aqueous solution of the compound containing at least 30% of the compound by weight.
Description
g~!~Z14~
3 COI~CE~ITRATION OF ORG~NIC CHEMICALS
4 F~:~OM DILUTE AQUEOUS SCLUTIONS
.7 . . ' .
8 This invention relates to a method for the concentration of organic -chemicals which are present in dilute aqueous solutions such as fermentation liquors.
1i'' . ' ' ' ' ' ` '' ' .
1~ BACKGROUND OF THE II~VENTION
l3 14~ The production of or~anic chemicals b~ microor~anisms is well known to those familiar with the fermentation art.
16 These chemicals are produced by the microorganisms in dilute 17 aaueous solutions, generally from about 1% to 10% by weight, 18 so that their recovery in pure form involves separatior. ~rom 19 a large quantity of water~. The expense of such separation h2s been so great that production of these chemicals by 21 ~ermentation has ~ot been able to compete with their 22 production based on petroleum fossil luel sources. However, 23 the gradual depletion o~ petroleum fossil fuel with the 24 resultant increase in prices of oetrochemical feeds~ocks has revived interests in such fermentation reactions which can ~6 convert carbohydrates that are renewable raw materials into 27 simple organic chem~cals.
i For these reasons, it is desirable to develop a low-cost process ~or separation o~ organic chemicals from 3 dilute aqueous solutions. Various methods have been proposed 4 for such separations. These include solvent extraction, ~ freeze crystallization, distillation and selective adsorption.
6 ~ ' 7 It is well known that activated carbon selectively .. ,., .- .-8 adsor'~s organic chemicals from aqueous solutions. The 9 adsorbed chemicals can then-be desorbed by various techniques 1'0 such as heating, displacing the adsorbed material with steam 11 or desorbinG the material with a sol~ent. Spence, U.S.
12 Patent 2,422,504, disclosed a process for recoverlng lower 13 fatty acids from a dilute aoueous solution. This involved 14 first adsorbing khe material on activated carbon. Then the carbon wa~ heated'to 100C under vacuum to remove a 16 part of the water plus some acid. Finally, the acid and 17 remaining water were extracted with a solvent and'the 18 solvent and acids were separated. The expensive heating 9 step detracts from this process.
21 Baieri, Canadian Patent 978,308, disclos~d a 22 method for recovering acetic acid and furfural from 23 sulfite waste liquors obtained as a by-product of paper 24 manufacture. In his process 9 the liquor was passed through a stream stripper and then through a carbon column to adsorb 26 some of the organic chemicals present- The chemicals were 27 subsequently desorbed using a solvent which was at leas~
3o l ' -2-~l 1 pzrtially vaporîzed. Suggested solvents were the lower
3 COI~CE~ITRATION OF ORG~NIC CHEMICALS
4 F~:~OM DILUTE AQUEOUS SCLUTIONS
.7 . . ' .
8 This invention relates to a method for the concentration of organic -chemicals which are present in dilute aqueous solutions such as fermentation liquors.
1i'' . ' ' ' ' ' ` '' ' .
1~ BACKGROUND OF THE II~VENTION
l3 14~ The production of or~anic chemicals b~ microor~anisms is well known to those familiar with the fermentation art.
16 These chemicals are produced by the microorganisms in dilute 17 aaueous solutions, generally from about 1% to 10% by weight, 18 so that their recovery in pure form involves separatior. ~rom 19 a large quantity of water~. The expense of such separation h2s been so great that production of these chemicals by 21 ~ermentation has ~ot been able to compete with their 22 production based on petroleum fossil luel sources. However, 23 the gradual depletion o~ petroleum fossil fuel with the 24 resultant increase in prices of oetrochemical feeds~ocks has revived interests in such fermentation reactions which can ~6 convert carbohydrates that are renewable raw materials into 27 simple organic chem~cals.
i For these reasons, it is desirable to develop a low-cost process ~or separation o~ organic chemicals from 3 dilute aqueous solutions. Various methods have been proposed 4 for such separations. These include solvent extraction, ~ freeze crystallization, distillation and selective adsorption.
6 ~ ' 7 It is well known that activated carbon selectively .. ,., .- .-8 adsor'~s organic chemicals from aqueous solutions. The 9 adsorbed chemicals can then-be desorbed by various techniques 1'0 such as heating, displacing the adsorbed material with steam 11 or desorbinG the material with a sol~ent. Spence, U.S.
12 Patent 2,422,504, disclosed a process for recoverlng lower 13 fatty acids from a dilute aoueous solution. This involved 14 first adsorbing khe material on activated carbon. Then the carbon wa~ heated'to 100C under vacuum to remove a 16 part of the water plus some acid. Finally, the acid and 17 remaining water were extracted with a solvent and'the 18 solvent and acids were separated. The expensive heating 9 step detracts from this process.
21 Baieri, Canadian Patent 978,308, disclos~d a 22 method for recovering acetic acid and furfural from 23 sulfite waste liquors obtained as a by-product of paper 24 manufacture. In his process 9 the liquor was passed through a stream stripper and then through a carbon column to adsorb 26 some of the organic chemicals present- The chemicals were 27 subsequently desorbed using a solvent which was at leas~
3o l ' -2-~l 1 pzrtially vaporîzed. Suggested solvents were the lower
2 alcohols, acetone, benzene, and ether. However, the examples were directed to the recovery of acetlc acid with 4 an alcohol which gave an ester or mixtures Or ester, alcohol and acid. The mixed product made th~s process 6 unattractive.
8 Baieri, U.S. Patent 4,016,180, disclosed a two-stage 9 adsorption-desorption process for concentrating sulfite waste liquors. The liquors are passed through a carbon column to 11 adsorb the organic chemicals. A more concentrated solution 12 of the chemicals was then obtained by the use of either 13 steam or a solvent to desorb the material. Examples include 14 the use of steam, methanol or ethanol to remove acetic acid from the carbon. When alcohols were used as desorbents, 16 mixtures containing esters~were obtained. The process 17 described by Baieri requlres quite complex equipment with 18 both upflow and downflow of the eluting solvent.
19 ' We have now discovered a greatly simplified 21. adsorption process for the concentration of organic 22 compounds ~rom dilute aqueous solutions which ls 23 ener~y-efficient and which permits the use of simple 2~ equipment. This process is particularly suitable for the concentration of or~anic compounds obtained by 26 microbial fermentations.
2g .
3o -3 ~ i 1 SU~ARY OF THE II~Vr.NTION
8 Baieri, U.S. Patent 4,016,180, disclosed a two-stage 9 adsorption-desorption process for concentrating sulfite waste liquors. The liquors are passed through a carbon column to 11 adsorb the organic chemicals. A more concentrated solution 12 of the chemicals was then obtained by the use of either 13 steam or a solvent to desorb the material. Examples include 14 the use of steam, methanol or ethanol to remove acetic acid from the carbon. When alcohols were used as desorbents, 16 mixtures containing esters~were obtained. The process 17 described by Baieri requlres quite complex equipment with 18 both upflow and downflow of the eluting solvent.
19 ' We have now discovered a greatly simplified 21. adsorption process for the concentration of organic 22 compounds ~rom dilute aqueous solutions which ls 23 ener~y-efficient and which permits the use of simple 2~ equipment. This process is particularly suitable for the concentration of or~anic compounds obtained by 26 microbial fermentations.
2g .
3o -3 ~ i 1 SU~ARY OF THE II~Vr.NTION
3 In accordance with the present invention, there
4 is provided a process for concentrating a dilute aqueous solution of an organic compound. The or~anic compound is 6 adsorbed on adsorbent carbon and then eluted from the 7 carbon with a volatile solvent before the volatile solvent 8 is separated from the mixture of solvent and eluted or&anic 9 compound. The improvement in the process comprises eluting the organic compound from the carbon by applying 11 va~ors o~ the volatile solvent to a bed of the carbon 12 maintained at a temperature a~ or slightly below the 13 condensation temperature of the solvent, at a rate of less 14 than about one-half bed volume per hour,until the volatile solvent is detected in the eluate. Then elution is 16 continued until about one-half additional bed volume of 17 eluate is collected which contains a concentrated aqueous 18 solution of the organic compound in the volatile solvent.
19 Volatile solvent is then evaporated to obtain an aqueous solution of the organic compound containing at least about 21 30% of the organic compound by weight.
23 ~ETAIL~D D~SCRIPTION OF THE INVF~TION
._ The process of this invention is suitable for the 26 - concentration of a varie~y of organic compounds from dilute 27 aqueous solutions. It can be used to concentrate any organic z~
compound which is readily adsorbed from solution by ac~iYa~ed 2 carbon and which can De desorbed by vapors Or a volatile 3 solvent. It is suitable ~or the concentration of dilute 4 solutions of acetic.acid, butanol, lactic acid, and ethanol.
It is particularly suitable ~or extraction o~ these compounds 6 from fermentation broths where they are produced by 7 microorganisms.
9 Any activated carbon can be used as an adsorbent, provided tha~ it adsorbs practical amounts of the organic 11 compound from dilute aqueous solution. It is preferably a 12 granular or beaded carbon of a mesh s,ze that permits good 13 flow of liquids through a bed of the carbon- Suitable carbons 14 are CPG~carbon, a granular carbon available from PPG Industriec Nuchzr HW-4 ~ a granular carbon available from khe ~estvaco 16 Chemical Corporation, and G~BAC, a beaded carbon available 17 from Union Carbide Corporation.
19 The organic compound is adsorbed from solution by mixing the solution with the adsorbent carbon. A convenient 21 method for carrying out this process is to place the carbon 22 in a column. The àilute solution of the organic compound 23 is then added.to the too of the column and allowed to flow 24 through the column by gravity. Alternatively, the material can be adsorbed by passin~ the solukion upward through the 26 column. The process is continued until the carbon is 27 saturated or nearly saturated with the or~anic compound. Once 28 ~ ~e ma~ks l the r"2terial has been adsorbed on the carbon, excess water and 2 unadsorbed material is allowed to drain from the column.
3 Passa~e of air or an inert g25 downward through the column can be used to increase the drainage rate and remove some additlonal water from the carbon.
7 Following the drainage step, a mixture of water and the organic compound is held by the carbon. Elution is 9 accomplished by passing the vapors Or a volatile solvent through the carbon. This step is conveniently carried out 11 by passing vapors of the volatile solvent in at the top 12 of a column containing the carbon with adsorbed material.
13 The solvent vapors condense in the column and pass from 14 the bottom of the column as a liquid.
16 In conducting the elution step, the column is 17 maintained at or slightly below the condensation temperature 18 of the volatile solvent. This means that the column 19 temperature ls between about 10C below, preferably about 5C belo~l, the boiling point and the boiling point of the 21 volatile solvent. The column is maintained at the desired 22 temperature ~y means of a heated jacket or similar device 23 and by the latent heat of vaporization ~iven up by the 24 condensing vapor.
26 A num~ber Or volatile solvents can be used in the 27 process of this invention- It is preferred to use a solvent l . ll `
:
that distills at a te.~perature sufficiently below the 2 boiling point of the organic material bein~ desorbed to 3 per~it separation of ~he solvent by distillation. A
4 solvent with a low specific heat and a low heat of , va~orization is par~icularl~ desirable. Furthermore, the 6 solvent should be one th~.t does not react with the organic compound and tha~ does not form an ~azeotrope with the . organic compound. It is also preferred to use a volatile 9 solvent which has a high degree of polarity. A solvent - which is most preferred for use in this process is acetone;
11 Other suitable solvents include diethyl ether; ethyl acetate, 12 isopropyl alcohol~ methanol and 2-butanone.
14 During the elu~ion step, the vapors of the volatile solvent are passed through the carbon, maintained at the 16 desired temperature, at such a rate th~t the solvent 17 condenses before it leaves the carb~n column. At first, 18 the rate at which the vapors are added to the column is 19 adjusted so that less than 0.5, preferably about 0.2 to 0.5, bed volumes per hour (BVH) of eluate is collected. This rate 21 of flow is maintained at lezst until the volatile solvent is 22 detected in the eluate. The first fraction eluted is mainly 23 ~ter. This greatly increases the concentration of the 24 organic compound in the material still adsorbed on the carbon.
3o -7-.`
1 There is an additional advantage of the pres~nt process when it is used to recover products froJn fermentations.
3 The first eluted fraction is pure enough so ~hat it can be 4 recycled ~irectly to the fermentor or reactor from which it came. This reduces the amount of fresh water needed and 6 the amount of wastewater produced by the process.
After the first fraction is eluted, the rate of 9 flow of solvent vapor can be increased !vo about 1.0 BVH, if desired, to accelerate the rate of desorpkion. The 11 second portion of eluate contains a mixture of organic 12 compound, water and volatile solvent. After about an 13 additional one-half bed volume of this mixture is collected, 14 elution is stQpped. The effluent mixture is now a concentrated aqueous solution of the or~anic compound in 16 the volatile solvent. Up to about 96~ of ~he water originally 17 associated ~;Jith the organic compound has ~een removed 18 without water distillation, thereby saving the ener~y cost 19 of this expensive process. The solvent then can be distilled from the effluent mixture and recovered for reuse.
21 The residue, after solvent removal, is an aqueous solu~ion 22 containing 2t least about 30% of the or~anic ~ompound by 23 weight. If the original solution contained 5~J or more of 24 the organic compound, the residue will con~ain from about 40~ to about 50% of the or~anic compound by weight.
3 _~_ l Thus, it ~s possible to concentrate a dilute 2 aqueous solution of an organic compound to a concentration 3 of about, 30~ or greater. Furthermore, the energJ
requirements of the process are low when the preferred solvent, acetone, is used due to the low boiling point, 6 low specific heat and,small latent heat of vaporization 7 of this solvent. The process is particularly suitable for 8 the concentration of organic compounds produced by 9 fermentation such as acetic acid and butanol.
1~0 .' ll The carbon can be regenerated after elution by 12 passing steam through it to remove solvent. Carbon so 13 regenerated after acetone elution regains its original '14 adsorptive capaclty. It can be reused many times.
- ~
16 The procedure of this inven~ion is further 17 illustrated by the following examples in which all parts 18 and percentages are by weight unless expressly stated to l9 be otherwise.
20' 21 EXAMPLE_l 23 In a 'jacketed column of 2.2 cm internal diameter 24' was placed 70 g (185 ml bed volume) of CPG carbon, a granular carbon available from the Pittsburgh Plate Glass Company.
26 The carbon was saturated with a 5% acetic acid solution at 27 pH 4.8. Twelve grams of acetic acid was adsorbed by the ~8 , 3 _g_ ' '~
c2rbon. After adsorption was complete, the carbon column 2 ~as drained and additional water was removed by pzssing an a-ir s~ream downward through the column. The column W25 4 ' then heated to a te~,perature of between 50 and 60C before acetone vapor was passed in at the top o~ the carbon 6 column. The effluent was removed from the bottom o~ the7 colu~n. The first 50-ml fractioll contained 2.33 g of 8 acetic acid and 47.2 g water by weight. A second fraction 9 (45 ml') contained 8.86 g of acetic acid and 8.05 g water by weight. The third fraction (50 ml) contained 0.87 g of 11 acetic acid and 2.15 g water by weight. A fihal 50-ml 12 fr~ction contained only 0.12 g of acetic acid.
14 This example illustrates that acetone vapor ~irst displaces nonadsorbed feed liquor from a carbon col~mn 16 which has been saturated with aa,ueous acetic acid. Then 17 the main amount of adsorbed acetic acid is eluted. This-18 second eluate on evaporation of the ace~one leaves an 19 aqu~ous acetic acid solution containing nearly 50~ acetic acid. The process is thus seen to be sui~able for the rapid 21 concer.tration of a solution of acetic acid.
- ' 23 EXAMPLE 2r 24 ' .The,process of Example 1 ~as re~eated except that 26 the temperature of the column during adsor~tion W25 ~aintained 27 carefully within a narrow temperature ran~e and the carbon 3o -10-11'.3Zl~1 ~
1 was satur2ted with 7.5% acetic acid solution at pH 2.5.
2 Experiments were run in which the temperature of the column 3 was maintained at 51C, 53~C~ 56C and 60C. When the 4 columns were maintained at 51C, 53C and 56C, all of the acetic acid adsorbed on the column was eluted in the 6 first 200 ml of eluate. However, when the column was held 7 at a temperature of 60C, only 77~D of acetic acid was 8 eluted in the f~rst 200 ml of eluate.
9 . ' .- ., .
This indicates that the column should be held at ll or slightly below the condensation temperature of the 12 acetone vapor (56C) in order for the rapi.d elution of the 13 acetic acid to occur.
~ .
17 In a ~acketed column of 2.2 cm internal diameter 18 was placed 70 g (180 ml bed volume) of ~luchar HW-40, a l9 granular carbon available from the Westvaco Chemical Corporation. The carbon was saturated with a 10% acetic 21 acid solution at pH 4.8. Af~er adsorption was comolete, 22 the carbon column was drained and additional water was 23 removed by passing an air stream downward througn the 24 column. The column was then heated to a specified tempera~ure be~ore acetone vapor was passed in at the top of the carbon 26 column. The effluent was removed from the bottom of the 27 column. Four fractions of approximately 25 ml, 20 ml, l ~
~ .
50 ~.1 and 50 ml respectiveIy were collected. The co~ents ecch fraction were an21yzed for acetic zcid and w2ter~
Resul~s of experiments run at v2rious temperatures between 4 30C ~nd 55C are reported in Table I.
-6 . TABL~ I
7 ~LUTIO;~ OF ACETIC ACID FROI~ N~CHAR H~T-40 CARBON
Fraction 1 _ Fraction 2 Fraction 3 Fraction 4 9 Column Acetic. Acetic Acetic Acetic Temp Acid Wa~er Acid Water Acid Wate~ Acid Wate~
1C) (%) (~) (%) (%) (%) (~o) (%) (%) . _ 11 -30 2.9~ 88.6612.54 75.49 15.1~3 18.83 3.06 2.46 12 30 2.52 g2.1112.24 77.60 15.12 17.28 2.88 1.77 ~.~8 89.92 9.9 81.9~ 17.76 20.94 3.3 1.87 13 40 3.78 88.44 6.1 86.72 19.68 23.79 3.3 2.37 4.14 88.2710.38 80.39 17.94 18.42 2.76 1;78 14 50 4.26 89.206.42 88.67 20.82 21.10 2.76 1.04 53 2.52 90.118.76 84.35 18.54 17.76 2.94 1.50 16 54 3.42 91.1 5.25 90.51 20.11 21.63 2.94 1.24 54 4.02 88.385.46 86.2 20.64 2~.70 2.58 0.89 17 54 3.54 90.564.86 87.8 21.6 22.47 2.7 0.87 1~ 55 3.36 89.593.54 89.54 lg.3~ 22.47 2.4 2.19 ~ 55 3.54 89.01 4.2 87.~ 19.92 2~.8 Z.7 1.~3 24 ~
26 . .
~ -12-L4.~ I
When the temperature of the column ls held ct 30C
2 or 40C by means of cooling ~ater in the ~acket, the acetone 3 vapor is confiensed so rapidly at the elu~ion rate used that 4 channeling tends to occur and separation of the water in the ~irst.two fractions is less complete. ~hen ~he temperature 6 of the column is maintained between 50C and 55C during the elution, the bulk of the water is eluted in the first tt"o fractions- and the adsorbed acetic acid is eluted in 9 the last two fractions. When the column temperature is maint2ined at 50 to 55C, Fractions 3 and 4, which contain ll over 95%- of the adsorbed acetic acid, can be combined to 12 give acetic acid solutions which, a'ter removal of acetone, 13 consist of approximately 50% aqueous solu~ions of acetic acid.
COMPARATIVE TEST
16 ~-7 The procedure of Example l was repeated except 18 that Nuchar HW-40 was used as the adsorbent and elution 19 was acco~plished using liquid acetone at 54-55C. The temperature o~ the column was maintained at 54-55C during 21 elu~ion. Again, the acetic acid t~as eluted in ~he first 22 200 ml of eluate -- mainly in the second 50-ml fraction.
23 Hot~ever, .this ~raction on an acetone-free basis t~as an 24 aqueous solution containing only about 35~ àcetic acid.
This comparative test demcnstrates that a much less 26 concentrated aqueous acetic 2cid solution is obtained when 27 acetone liquid rather than acetone vapor is applied to the 28 column to elute the acid.
2~
3o -13--l ~ ~ l EXAMPL~ 4 The carbon column described in Example 3 ~"as 4 saturated with a 2.5% acetic acid solution at pH 4.8.
After adsorption was complete, the carbon column was 6 drained and additional water was removed by ~assing an air 7 stream downward through the column. The column w2s ne2ted 8~ to 54C before acetone vapor was passed in at the top of 9 the column. The effluent was removed from the bottom of the column. Four fractions of approximately 50 ml each 1 were collected. The first fraction (average of 3 runs) 12 contained 96.5% water and only l.43% acetic acid. Combined 13 Fractions 2 and 3 (average of 3 runs) contained 13.5% acetic .14 acid and 21.0% water. Only traces of zcetic acid were present in Frac~ion 4.
17 -This example demonstrates.that a 39% acekiG acid 18 solution can be-obtained from a 2.5% acetic acid solution 19 (pH 4.8) by this process, which removes about 96~ Or the 2Q water originally associated with this acetic acid.
24 The procedure of Example 4 was repeated except that the carbon column was saturated with a 1.25~ acetic 26 acid solution at pH 4-8. A~ain, the bulk of the acetic 27 2cid was recovered in Fractions 2 and 3 which, af~er --,O -14-1 combinin3 and subtracting the acetone, give a 34% aqueous 2 so].ution o~ acetic acid. This process removes over 97%
3 of the wzter originally associated with this acetic acid.
4 This example further demonstrates the usefulness of this process for concentrating very dilute acetic acid solutions.
9 The experiment of Example 2 was repeated except that the carbon W2S saturated with 5% acetic acid solution 11 at pH 2.5, me~hanol vapor (condensation temperature 65C) 12 was used for the elution and the column temperatures were 13 held at 61C~ 66C and 70C respectively. A quantitative 14 elution of acetic acid was achieved only when the temperature was a~ 61C. When the temperatures were at 66C and 70C, 16 acetic acid recoveries of 78% and 61.5% respectively were 17 observed.
19 These tests further emphasize the importance of conducting the elution of the acetic acid at a temperature ~1 at or slightly below the condensation tem~erature o~ the 22 vapor of the eluting solvent.
23 . . .
26 The procedure of Example 4 W2S repeated using a 27 5g acetic acid solution at pH 4.8 except that the elua'ce 3o ~15-1 ~as isopropyl alcohol vapor (conàensa'tion ~emperature ~2C) nd the temperature of the column was held at 80C during 3 the elution. Analysis of ~he eluate was as follows:
Acetic .. Volume AcidWater 6 Fract~on (ml) (g) (%~
7 1 40 1.85 94.~
2 50 5.61 23-S
8 3 5 0.60 2.1 9 4 50 0.12 1.2 11 . ~XAMPLE 8 13 The elution procedure of Example 7 was repeated 14 except that the eluate W2S ethyl acetate vapor (condensation te`mperature 77C) and the temperature of the column was held 16 at 70C durin~ the elution. Analysis of the eluate is as 17 ollows:
.19 .. ..
Acetic Volume Acid ~ater 21 . Fraction (ml) (~
22 . 1 25 1.94 88.3 2 20 2.5~ 14.5 23 3 50 3.75 8.8 4 50 1.71 6-5 24 5 5 o.63 4,7 . .
28 .
1, 2g ..
3 -16- `
3 The elution procedure of Example 7 was repeated 4 except that 2-butanone vapor (condensation temperature 30C) was used as the eluate and the column was held at 76C.
6 Analysis of the eluate W2S as follows:
8 Acetic Volume AcidWater g Fraction (ml~ (g) (%) 1 25 1.85 92.8 . 2 20 4.o8 64.2 '~1 - 3 50 4.26 16;2 12 l~ 50 o.60 4.3 14 Examples 6, 7~ 8 and 9 demonstrate that vapors f solvents other than acetone can be used in the process 16 of this invention.
19 , . The elution procedure of Example 7 was followed 21 except that diethyl ether vapor (condensa~ion temperature 22 35C) was used as the eluate and the column was held at 23 34C during the elution. The ~irst fraction of eluate 24 separated into two layers which were analyzed separately.
Analysis of the eluate was as follows:
3~ -17-1 Acetic Volume Acid Water 2 ~action (ml) (~
3 1 50 (upper 30) 1.82 4.2 (lower 20) 1.50 92.0 4 2 50 2.79 3.6 3 5 1.50 2.6 4 50 0.75 1.8 .50 0.36 1.5 7 Ether vapor appears to be less sa~isfactor~J than 8 the oJher eluates. ~ater is retained on the carbon ionger 9 when ~his solvent is used, and it is more difficult to remove the acetic acid.
14 The general procedure of Example 3 wa~ followed except thzt 400 ml of a 5.1% solution of lactic acid was 16 applied to the column and tbe tempera~ure of the column 17 was held at 54G during elution. Analysis of the eluate 18 was as follows:
Lactic Volume Acid Water 21 Fraction (ml) (g) (%) 22 1 40 1.98 95.0 2 50 10.13 28.~ .
23 ~ . 50 1.44 1.
. 4 50 0.45 o.8 2g 3o -18-1 Combined Fractions 2 and 3, a~ter evapor2tion o.
2 acetone, ~ive an aqueous solution containing about 40~
3 lactic acid. It is thus seen that the ~resent invention 4 is suitabie for the concentration of a dilute lact~c acid solution.
7 _XA~LE 12 9 mhe general procedure of Example 3 W25 ~ollowed except that 400 ml of a clarified ferment2tion broth 11 containing 8.3% ethanol was applied to the column, and 12 the temperature o~ the column was held at 54C during elution.
13 The broth was obtained by the fermentation of a starch 14 hydrolyzate solution with the yeast Saccharo~yces cerevisiae.
The fermentation broth also contained 1.2% glycerol and 16 0.4% lactic acid. Analysis of the eluate was as follows:
VolumeEthanol ~7ater 19 Fraction (ml) (%) (~) 1 25 9.6 90.~
2 15 13.0 87.0 21 3 50 13.5 19.8 22 4 50 0.1 1.8 24 This example demonstrates that the process of the present invention is suitable ~or concentrating the ethanol 226 solution produced by a fermentation reaction.
'O -1 9-! I
1 1 ~YA~PLE 13 ' 2 .' 3 The general procedure of Example 3 was followed 4 . ' except that 1750 ml of a crude fermentation broth containing 1.4,~ butanol and lesser amounts of acetone, ethanol and fatty 6 ~cids was~used and the temperature of the column was held at 7 54C during elution. This broth wa,s obtained by the 8 fermentation of a starch hydrolyzate solution by the 9 bacterium Clostridium acetobutylicum. The broth also contained 4.9% carbohydrate. Analysis of the eluate ~1as 11 as follows:
13 .
Volume Butanol Water Carbohydrate 14 Fraction,. (ml) (%) (P) (%) . 1 25 . 1.3 84.0 7OQ
2 , 15 13.9 57-3 6.5 16 3 50 17-7 22.5 1.5 . 4 50 2.6 2.8 0.2 .
17 5 50 0.1 o.8 o.l 18 .
i9 In some parallel experiments, the second fraction separated into two layers with the upper layer contalning 21 more butanol and the lower layer containing more carbohydrate.
23 This example demonstrates that the process of .
24 this invention can be used to concentr~te butanol obtained by fermentation even when the crude fermentation broth 26 contains much unfermented carbohydrate material.
27 ' .
19 Volatile solvent is then evaporated to obtain an aqueous solution of the organic compound containing at least about 21 30% of the organic compound by weight.
23 ~ETAIL~D D~SCRIPTION OF THE INVF~TION
._ The process of this invention is suitable for the 26 - concentration of a varie~y of organic compounds from dilute 27 aqueous solutions. It can be used to concentrate any organic z~
compound which is readily adsorbed from solution by ac~iYa~ed 2 carbon and which can De desorbed by vapors Or a volatile 3 solvent. It is suitable ~or the concentration of dilute 4 solutions of acetic.acid, butanol, lactic acid, and ethanol.
It is particularly suitable ~or extraction o~ these compounds 6 from fermentation broths where they are produced by 7 microorganisms.
9 Any activated carbon can be used as an adsorbent, provided tha~ it adsorbs practical amounts of the organic 11 compound from dilute aqueous solution. It is preferably a 12 granular or beaded carbon of a mesh s,ze that permits good 13 flow of liquids through a bed of the carbon- Suitable carbons 14 are CPG~carbon, a granular carbon available from PPG Industriec Nuchzr HW-4 ~ a granular carbon available from khe ~estvaco 16 Chemical Corporation, and G~BAC, a beaded carbon available 17 from Union Carbide Corporation.
19 The organic compound is adsorbed from solution by mixing the solution with the adsorbent carbon. A convenient 21 method for carrying out this process is to place the carbon 22 in a column. The àilute solution of the organic compound 23 is then added.to the too of the column and allowed to flow 24 through the column by gravity. Alternatively, the material can be adsorbed by passin~ the solukion upward through the 26 column. The process is continued until the carbon is 27 saturated or nearly saturated with the or~anic compound. Once 28 ~ ~e ma~ks l the r"2terial has been adsorbed on the carbon, excess water and 2 unadsorbed material is allowed to drain from the column.
3 Passa~e of air or an inert g25 downward through the column can be used to increase the drainage rate and remove some additlonal water from the carbon.
7 Following the drainage step, a mixture of water and the organic compound is held by the carbon. Elution is 9 accomplished by passing the vapors Or a volatile solvent through the carbon. This step is conveniently carried out 11 by passing vapors of the volatile solvent in at the top 12 of a column containing the carbon with adsorbed material.
13 The solvent vapors condense in the column and pass from 14 the bottom of the column as a liquid.
16 In conducting the elution step, the column is 17 maintained at or slightly below the condensation temperature 18 of the volatile solvent. This means that the column 19 temperature ls between about 10C below, preferably about 5C belo~l, the boiling point and the boiling point of the 21 volatile solvent. The column is maintained at the desired 22 temperature ~y means of a heated jacket or similar device 23 and by the latent heat of vaporization ~iven up by the 24 condensing vapor.
26 A num~ber Or volatile solvents can be used in the 27 process of this invention- It is preferred to use a solvent l . ll `
:
that distills at a te.~perature sufficiently below the 2 boiling point of the organic material bein~ desorbed to 3 per~it separation of ~he solvent by distillation. A
4 solvent with a low specific heat and a low heat of , va~orization is par~icularl~ desirable. Furthermore, the 6 solvent should be one th~.t does not react with the organic compound and tha~ does not form an ~azeotrope with the . organic compound. It is also preferred to use a volatile 9 solvent which has a high degree of polarity. A solvent - which is most preferred for use in this process is acetone;
11 Other suitable solvents include diethyl ether; ethyl acetate, 12 isopropyl alcohol~ methanol and 2-butanone.
14 During the elu~ion step, the vapors of the volatile solvent are passed through the carbon, maintained at the 16 desired temperature, at such a rate th~t the solvent 17 condenses before it leaves the carb~n column. At first, 18 the rate at which the vapors are added to the column is 19 adjusted so that less than 0.5, preferably about 0.2 to 0.5, bed volumes per hour (BVH) of eluate is collected. This rate 21 of flow is maintained at lezst until the volatile solvent is 22 detected in the eluate. The first fraction eluted is mainly 23 ~ter. This greatly increases the concentration of the 24 organic compound in the material still adsorbed on the carbon.
3o -7-.`
1 There is an additional advantage of the pres~nt process when it is used to recover products froJn fermentations.
3 The first eluted fraction is pure enough so ~hat it can be 4 recycled ~irectly to the fermentor or reactor from which it came. This reduces the amount of fresh water needed and 6 the amount of wastewater produced by the process.
After the first fraction is eluted, the rate of 9 flow of solvent vapor can be increased !vo about 1.0 BVH, if desired, to accelerate the rate of desorpkion. The 11 second portion of eluate contains a mixture of organic 12 compound, water and volatile solvent. After about an 13 additional one-half bed volume of this mixture is collected, 14 elution is stQpped. The effluent mixture is now a concentrated aqueous solution of the or~anic compound in 16 the volatile solvent. Up to about 96~ of ~he water originally 17 associated ~;Jith the organic compound has ~een removed 18 without water distillation, thereby saving the ener~y cost 19 of this expensive process. The solvent then can be distilled from the effluent mixture and recovered for reuse.
21 The residue, after solvent removal, is an aqueous solu~ion 22 containing 2t least about 30% of the or~anic ~ompound by 23 weight. If the original solution contained 5~J or more of 24 the organic compound, the residue will con~ain from about 40~ to about 50% of the or~anic compound by weight.
3 _~_ l Thus, it ~s possible to concentrate a dilute 2 aqueous solution of an organic compound to a concentration 3 of about, 30~ or greater. Furthermore, the energJ
requirements of the process are low when the preferred solvent, acetone, is used due to the low boiling point, 6 low specific heat and,small latent heat of vaporization 7 of this solvent. The process is particularly suitable for 8 the concentration of organic compounds produced by 9 fermentation such as acetic acid and butanol.
1~0 .' ll The carbon can be regenerated after elution by 12 passing steam through it to remove solvent. Carbon so 13 regenerated after acetone elution regains its original '14 adsorptive capaclty. It can be reused many times.
- ~
16 The procedure of this inven~ion is further 17 illustrated by the following examples in which all parts 18 and percentages are by weight unless expressly stated to l9 be otherwise.
20' 21 EXAMPLE_l 23 In a 'jacketed column of 2.2 cm internal diameter 24' was placed 70 g (185 ml bed volume) of CPG carbon, a granular carbon available from the Pittsburgh Plate Glass Company.
26 The carbon was saturated with a 5% acetic acid solution at 27 pH 4.8. Twelve grams of acetic acid was adsorbed by the ~8 , 3 _g_ ' '~
c2rbon. After adsorption was complete, the carbon column 2 ~as drained and additional water was removed by pzssing an a-ir s~ream downward through the column. The column W25 4 ' then heated to a te~,perature of between 50 and 60C before acetone vapor was passed in at the top o~ the carbon 6 column. The effluent was removed from the bottom o~ the7 colu~n. The first 50-ml fractioll contained 2.33 g of 8 acetic acid and 47.2 g water by weight. A second fraction 9 (45 ml') contained 8.86 g of acetic acid and 8.05 g water by weight. The third fraction (50 ml) contained 0.87 g of 11 acetic acid and 2.15 g water by weight. A fihal 50-ml 12 fr~ction contained only 0.12 g of acetic acid.
14 This example illustrates that acetone vapor ~irst displaces nonadsorbed feed liquor from a carbon col~mn 16 which has been saturated with aa,ueous acetic acid. Then 17 the main amount of adsorbed acetic acid is eluted. This-18 second eluate on evaporation of the ace~one leaves an 19 aqu~ous acetic acid solution containing nearly 50~ acetic acid. The process is thus seen to be sui~able for the rapid 21 concer.tration of a solution of acetic acid.
- ' 23 EXAMPLE 2r 24 ' .The,process of Example 1 ~as re~eated except that 26 the temperature of the column during adsor~tion W25 ~aintained 27 carefully within a narrow temperature ran~e and the carbon 3o -10-11'.3Zl~1 ~
1 was satur2ted with 7.5% acetic acid solution at pH 2.5.
2 Experiments were run in which the temperature of the column 3 was maintained at 51C, 53~C~ 56C and 60C. When the 4 columns were maintained at 51C, 53C and 56C, all of the acetic acid adsorbed on the column was eluted in the 6 first 200 ml of eluate. However, when the column was held 7 at a temperature of 60C, only 77~D of acetic acid was 8 eluted in the f~rst 200 ml of eluate.
9 . ' .- ., .
This indicates that the column should be held at ll or slightly below the condensation temperature of the 12 acetone vapor (56C) in order for the rapi.d elution of the 13 acetic acid to occur.
~ .
17 In a ~acketed column of 2.2 cm internal diameter 18 was placed 70 g (180 ml bed volume) of ~luchar HW-40, a l9 granular carbon available from the Westvaco Chemical Corporation. The carbon was saturated with a 10% acetic 21 acid solution at pH 4.8. Af~er adsorption was comolete, 22 the carbon column was drained and additional water was 23 removed by passing an air stream downward througn the 24 column. The column was then heated to a specified tempera~ure be~ore acetone vapor was passed in at the top of the carbon 26 column. The effluent was removed from the bottom of the 27 column. Four fractions of approximately 25 ml, 20 ml, l ~
~ .
50 ~.1 and 50 ml respectiveIy were collected. The co~ents ecch fraction were an21yzed for acetic zcid and w2ter~
Resul~s of experiments run at v2rious temperatures between 4 30C ~nd 55C are reported in Table I.
-6 . TABL~ I
7 ~LUTIO;~ OF ACETIC ACID FROI~ N~CHAR H~T-40 CARBON
Fraction 1 _ Fraction 2 Fraction 3 Fraction 4 9 Column Acetic. Acetic Acetic Acetic Temp Acid Wa~er Acid Water Acid Wate~ Acid Wate~
1C) (%) (~) (%) (%) (%) (~o) (%) (%) . _ 11 -30 2.9~ 88.6612.54 75.49 15.1~3 18.83 3.06 2.46 12 30 2.52 g2.1112.24 77.60 15.12 17.28 2.88 1.77 ~.~8 89.92 9.9 81.9~ 17.76 20.94 3.3 1.87 13 40 3.78 88.44 6.1 86.72 19.68 23.79 3.3 2.37 4.14 88.2710.38 80.39 17.94 18.42 2.76 1;78 14 50 4.26 89.206.42 88.67 20.82 21.10 2.76 1.04 53 2.52 90.118.76 84.35 18.54 17.76 2.94 1.50 16 54 3.42 91.1 5.25 90.51 20.11 21.63 2.94 1.24 54 4.02 88.385.46 86.2 20.64 2~.70 2.58 0.89 17 54 3.54 90.564.86 87.8 21.6 22.47 2.7 0.87 1~ 55 3.36 89.593.54 89.54 lg.3~ 22.47 2.4 2.19 ~ 55 3.54 89.01 4.2 87.~ 19.92 2~.8 Z.7 1.~3 24 ~
26 . .
~ -12-L4.~ I
When the temperature of the column ls held ct 30C
2 or 40C by means of cooling ~ater in the ~acket, the acetone 3 vapor is confiensed so rapidly at the elu~ion rate used that 4 channeling tends to occur and separation of the water in the ~irst.two fractions is less complete. ~hen ~he temperature 6 of the column is maintained between 50C and 55C during the elution, the bulk of the water is eluted in the first tt"o fractions- and the adsorbed acetic acid is eluted in 9 the last two fractions. When the column temperature is maint2ined at 50 to 55C, Fractions 3 and 4, which contain ll over 95%- of the adsorbed acetic acid, can be combined to 12 give acetic acid solutions which, a'ter removal of acetone, 13 consist of approximately 50% aqueous solu~ions of acetic acid.
COMPARATIVE TEST
16 ~-7 The procedure of Example l was repeated except 18 that Nuchar HW-40 was used as the adsorbent and elution 19 was acco~plished using liquid acetone at 54-55C. The temperature o~ the column was maintained at 54-55C during 21 elu~ion. Again, the acetic acid t~as eluted in ~he first 22 200 ml of eluate -- mainly in the second 50-ml fraction.
23 Hot~ever, .this ~raction on an acetone-free basis t~as an 24 aqueous solution containing only about 35~ àcetic acid.
This comparative test demcnstrates that a much less 26 concentrated aqueous acetic 2cid solution is obtained when 27 acetone liquid rather than acetone vapor is applied to the 28 column to elute the acid.
2~
3o -13--l ~ ~ l EXAMPL~ 4 The carbon column described in Example 3 ~"as 4 saturated with a 2.5% acetic acid solution at pH 4.8.
After adsorption was complete, the carbon column was 6 drained and additional water was removed by ~assing an air 7 stream downward through the column. The column w2s ne2ted 8~ to 54C before acetone vapor was passed in at the top of 9 the column. The effluent was removed from the bottom of the column. Four fractions of approximately 50 ml each 1 were collected. The first fraction (average of 3 runs) 12 contained 96.5% water and only l.43% acetic acid. Combined 13 Fractions 2 and 3 (average of 3 runs) contained 13.5% acetic .14 acid and 21.0% water. Only traces of zcetic acid were present in Frac~ion 4.
17 -This example demonstrates.that a 39% acekiG acid 18 solution can be-obtained from a 2.5% acetic acid solution 19 (pH 4.8) by this process, which removes about 96~ Or the 2Q water originally associated with this acetic acid.
24 The procedure of Example 4 was repeated except that the carbon column was saturated with a 1.25~ acetic 26 acid solution at pH 4-8. A~ain, the bulk of the acetic 27 2cid was recovered in Fractions 2 and 3 which, af~er --,O -14-1 combinin3 and subtracting the acetone, give a 34% aqueous 2 so].ution o~ acetic acid. This process removes over 97%
3 of the wzter originally associated with this acetic acid.
4 This example further demonstrates the usefulness of this process for concentrating very dilute acetic acid solutions.
9 The experiment of Example 2 was repeated except that the carbon W2S saturated with 5% acetic acid solution 11 at pH 2.5, me~hanol vapor (condensation temperature 65C) 12 was used for the elution and the column temperatures were 13 held at 61C~ 66C and 70C respectively. A quantitative 14 elution of acetic acid was achieved only when the temperature was a~ 61C. When the temperatures were at 66C and 70C, 16 acetic acid recoveries of 78% and 61.5% respectively were 17 observed.
19 These tests further emphasize the importance of conducting the elution of the acetic acid at a temperature ~1 at or slightly below the condensation tem~erature o~ the 22 vapor of the eluting solvent.
23 . . .
26 The procedure of Example 4 W2S repeated using a 27 5g acetic acid solution at pH 4.8 except that the elua'ce 3o ~15-1 ~as isopropyl alcohol vapor (conàensa'tion ~emperature ~2C) nd the temperature of the column was held at 80C during 3 the elution. Analysis of ~he eluate was as follows:
Acetic .. Volume AcidWater 6 Fract~on (ml) (g) (%~
7 1 40 1.85 94.~
2 50 5.61 23-S
8 3 5 0.60 2.1 9 4 50 0.12 1.2 11 . ~XAMPLE 8 13 The elution procedure of Example 7 was repeated 14 except that the eluate W2S ethyl acetate vapor (condensation te`mperature 77C) and the temperature of the column was held 16 at 70C durin~ the elution. Analysis of the eluate is as 17 ollows:
.19 .. ..
Acetic Volume Acid ~ater 21 . Fraction (ml) (~
22 . 1 25 1.94 88.3 2 20 2.5~ 14.5 23 3 50 3.75 8.8 4 50 1.71 6-5 24 5 5 o.63 4,7 . .
28 .
1, 2g ..
3 -16- `
3 The elution procedure of Example 7 was repeated 4 except that 2-butanone vapor (condensation temperature 30C) was used as the eluate and the column was held at 76C.
6 Analysis of the eluate W2S as follows:
8 Acetic Volume AcidWater g Fraction (ml~ (g) (%) 1 25 1.85 92.8 . 2 20 4.o8 64.2 '~1 - 3 50 4.26 16;2 12 l~ 50 o.60 4.3 14 Examples 6, 7~ 8 and 9 demonstrate that vapors f solvents other than acetone can be used in the process 16 of this invention.
19 , . The elution procedure of Example 7 was followed 21 except that diethyl ether vapor (condensa~ion temperature 22 35C) was used as the eluate and the column was held at 23 34C during the elution. The ~irst fraction of eluate 24 separated into two layers which were analyzed separately.
Analysis of the eluate was as follows:
3~ -17-1 Acetic Volume Acid Water 2 ~action (ml) (~
3 1 50 (upper 30) 1.82 4.2 (lower 20) 1.50 92.0 4 2 50 2.79 3.6 3 5 1.50 2.6 4 50 0.75 1.8 .50 0.36 1.5 7 Ether vapor appears to be less sa~isfactor~J than 8 the oJher eluates. ~ater is retained on the carbon ionger 9 when ~his solvent is used, and it is more difficult to remove the acetic acid.
14 The general procedure of Example 3 wa~ followed except thzt 400 ml of a 5.1% solution of lactic acid was 16 applied to the column and tbe tempera~ure of the column 17 was held at 54G during elution. Analysis of the eluate 18 was as follows:
Lactic Volume Acid Water 21 Fraction (ml) (g) (%) 22 1 40 1.98 95.0 2 50 10.13 28.~ .
23 ~ . 50 1.44 1.
. 4 50 0.45 o.8 2g 3o -18-1 Combined Fractions 2 and 3, a~ter evapor2tion o.
2 acetone, ~ive an aqueous solution containing about 40~
3 lactic acid. It is thus seen that the ~resent invention 4 is suitabie for the concentration of a dilute lact~c acid solution.
7 _XA~LE 12 9 mhe general procedure of Example 3 W25 ~ollowed except that 400 ml of a clarified ferment2tion broth 11 containing 8.3% ethanol was applied to the column, and 12 the temperature o~ the column was held at 54C during elution.
13 The broth was obtained by the fermentation of a starch 14 hydrolyzate solution with the yeast Saccharo~yces cerevisiae.
The fermentation broth also contained 1.2% glycerol and 16 0.4% lactic acid. Analysis of the eluate was as follows:
VolumeEthanol ~7ater 19 Fraction (ml) (%) (~) 1 25 9.6 90.~
2 15 13.0 87.0 21 3 50 13.5 19.8 22 4 50 0.1 1.8 24 This example demonstrates that the process of the present invention is suitable ~or concentrating the ethanol 226 solution produced by a fermentation reaction.
'O -1 9-! I
1 1 ~YA~PLE 13 ' 2 .' 3 The general procedure of Example 3 was followed 4 . ' except that 1750 ml of a crude fermentation broth containing 1.4,~ butanol and lesser amounts of acetone, ethanol and fatty 6 ~cids was~used and the temperature of the column was held at 7 54C during elution. This broth wa,s obtained by the 8 fermentation of a starch hydrolyzate solution by the 9 bacterium Clostridium acetobutylicum. The broth also contained 4.9% carbohydrate. Analysis of the eluate ~1as 11 as follows:
13 .
Volume Butanol Water Carbohydrate 14 Fraction,. (ml) (%) (P) (%) . 1 25 . 1.3 84.0 7OQ
2 , 15 13.9 57-3 6.5 16 3 50 17-7 22.5 1.5 . 4 50 2.6 2.8 0.2 .
17 5 50 0.1 o.8 o.l 18 .
i9 In some parallel experiments, the second fraction separated into two layers with the upper layer contalning 21 more butanol and the lower layer containing more carbohydrate.
23 This example demonstrates that the process of .
24 this invention can be used to concentr~te butanol obtained by fermentation even when the crude fermentation broth 26 contains much unfermented carbohydrate material.
27 ' .
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for concentrating a dilute aqueous solution of an organic compound by adsorbing the organic compound on an adsorbent carbon, eluting the organic compound from the carbon with a volatile solvent, and separating the volatile solvent from the mixture of solvent and eluted organic compound, characterized in that it comprises applying vapors of the volatile solvent to a bed of the carbon containing adsorbed organic compound, said bed being maintained at a temperature at or slightly below the condensation temperature of -the solvent, at a rate of less than about one-half bed volume per hour until the volatile solvent is detected in the eluate, continuing to apply said vapors until about one-half bed volume of eluate containing a concentrated aqueous solution of the organic compound in the volatile solvent is collected, and evaporating the volatile solvent from said one-half bed volume of eluate to obtain an aqueous solution of the organic compound containing at least about 30% of the organic compound by weight.
2. The process of claim 1 characterized in that the adsorbent carbon is held in a column, the vapors of the volatile solvent are introduced into the top of the carbon column, and the condensate is removed from the bottom of the column.
3. The process of claim 1 characterized in that air is passed through the bed of carbon containing adsorbed organic compound before the vapors of volatile solvent are passed through the bed of carbon.
4. The process of claims 1 or 2 or 3 characterized in that the volatile solvent is acetone.
5. The processes of claims 1, 2 or 3 characterized in that the volatile solvent is selected from the group consisting of 2-butanone, ethyl acetate, isopropyl alcohol, methanol and diethyl ether.
6. The process of claim 1 characterized in that the organic compound is acetic acid, and the dilute aqueous acetic acid solution is a fermentation broth obtained by cultivating an acetic acid-producing microorganism.
7. The process of claim 1 characterized in that the organic compound is butanol, and the dilute aqueous butanol solution is a fermentation broth obtained by cultivating a butanol-producing microorganism.
8. The process of claim 1 characterized in that the organic compound is ethanol, and the dilute aqueous ethanol solution is a fermentation broth obtained by cultivating an ethanol-producing microorganism.
9. The process of claim 1 characterized in that the organic compound is lactic acid, and the dilute aqueous lactic acid solution is a fermentation broth obtained by cultivating a lactic acid-producing microorganism.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/327,849 US4691055A (en) | 1981-12-07 | 1981-12-07 | Concentration of organic chemicals from dilute aqueous solutions |
| US327,849 | 1989-03-23 |
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| Publication Number | Publication Date |
|---|---|
| CA1192141A true CA1192141A (en) | 1985-08-20 |
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| US (1) | US4691055A (en) |
| EP (1) | EP0081211B1 (en) |
| JP (1) | JPS58116687A (en) |
| KR (1) | KR880002537B1 (en) |
| AR (1) | AR228109A1 (en) |
| AT (1) | ATE19474T1 (en) |
| AU (1) | AU556123B2 (en) |
| BR (1) | BR8207045A (en) |
| CA (1) | CA1192141A (en) |
| DE (1) | DE3270897D1 (en) |
| DK (1) | DK161123C (en) |
| ES (1) | ES8401858A1 (en) |
| FI (1) | FI76700C (en) |
| GB (1) | GB2112775B (en) |
| IE (1) | IE53565B1 (en) |
| IN (1) | IN158318B (en) |
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| MY (1) | MY8600483A (en) |
| NZ (1) | NZ202207A (en) |
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| DE3415141A1 (en) * | 1984-04-21 | 1985-10-31 | Basf Ag, 6700 Ludwigshafen | METHOD FOR ISOLATING LACTIC ACID FROM SOLID-CONTAINING AQUEOUS SOLUTIONS |
| US4670155A (en) * | 1985-03-06 | 1987-06-02 | The Regents Of The University Of California | Process for sorption solute recovery |
| NZ212523A (en) * | 1985-06-24 | 1989-01-06 | Univ Massey | Mobile phase for purification of proteins by high performance liquid chromatography |
| KR101737325B1 (en) * | 2010-08-19 | 2017-05-22 | 삼성전자주식회사 | Method and apparatus for reducing decreasing of qualitly of experience in a multimedia system |
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| CA529982A (en) * | 1956-09-04 | Spence Oswald | Recovery of lower aliphatic acids from dilute aqueous solutions | |
| US2422504A (en) * | 1944-02-05 | 1947-06-17 | Masonite Corp | Recovery of lower aliphatic acids from dilute aqueous solution |
| NL151348B (en) * | 1966-03-31 | 1976-11-15 | Hoechst Ag | PROCESS FOR THE PURIFICATION OF ACETIC ACID CONTAINING MERIC ACID IN A QUANTITY OF UP TO 10% BY weight. |
| CA978308A (en) * | 1971-09-09 | 1975-11-25 | Scott Paper Company | Use of activated carbon to recover and separate chemicals produced during pulping operations |
| US3965036A (en) * | 1972-12-11 | 1976-06-22 | The Dow Chemical Company | Regeneration of activated carbon with a solution of sorbed species in a solvent |
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1981
- 1981-12-07 US US06/327,849 patent/US4691055A/en not_active Expired - Lifetime
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1982
- 1982-10-18 AU AU89447/82A patent/AU556123B2/en not_active Ceased
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- 1982-10-28 AR AR291132A patent/AR228109A1/en active
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- 1982-12-06 KR KR8205466A patent/KR880002537B1/en active
- 1982-12-06 ES ES517932A patent/ES8401858A1/en not_active Expired
- 1982-12-06 DK DK539482A patent/DK161123C/en not_active IP Right Cessation
- 1982-12-07 JP JP57213483A patent/JPS58116687A/en active Granted
-
1986
- 1986-12-30 MY MY483/86A patent/MY8600483A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| IE53565B1 (en) | 1988-12-07 |
| IE822635L (en) | 1983-06-07 |
| ES517932A0 (en) | 1984-01-01 |
| FI76700C (en) | 1988-12-12 |
| MY8600483A (en) | 1986-12-31 |
| EP0081211A3 (en) | 1984-04-25 |
| KR880002537B1 (en) | 1988-11-29 |
| IN158318B (en) | 1986-10-18 |
| GB2112775B (en) | 1985-10-02 |
| DE3270897D1 (en) | 1986-06-05 |
| EP0081211B1 (en) | 1986-04-30 |
| JPS58116687A (en) | 1983-07-11 |
| DK539482A (en) | 1983-06-08 |
| AR228109A1 (en) | 1983-01-14 |
| BR8207045A (en) | 1983-10-11 |
| US4691055A (en) | 1987-09-01 |
| EP0081211A2 (en) | 1983-06-15 |
| FI76700B (en) | 1988-08-31 |
| JPH0368676B2 (en) | 1991-10-29 |
| FI824006A0 (en) | 1982-11-22 |
| KR840002662A (en) | 1984-07-16 |
| DK161123C (en) | 1991-11-18 |
| MX156851A (en) | 1988-10-06 |
| AU8944782A (en) | 1983-06-16 |
| DK161123B (en) | 1991-06-03 |
| ZA828424B (en) | 1983-09-28 |
| PH20376A (en) | 1986-12-08 |
| NZ202207A (en) | 1985-11-08 |
| ATE19474T1 (en) | 1986-05-15 |
| FI824006L (en) | 1983-06-08 |
| GB2112775A (en) | 1983-07-27 |
| ES8401858A1 (en) | 1984-01-01 |
| AU556123B2 (en) | 1986-10-23 |
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