US20030000894A1 - Process for treating liquid - Google Patents
Process for treating liquid Download PDFInfo
- Publication number
- US20030000894A1 US20030000894A1 US10/225,016 US22501602A US2003000894A1 US 20030000894 A1 US20030000894 A1 US 20030000894A1 US 22501602 A US22501602 A US 22501602A US 2003000894 A1 US2003000894 A1 US 2003000894A1
- Authority
- US
- United States
- Prior art keywords
- citric acid
- less desirable
- desirable component
- process according
- centrifuge
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000000034 method Methods 0.000 title claims abstract description 52
- 239000007788 liquid Substances 0.000 title claims abstract description 18
- KRKNYBCHXYNGOX-UHFFFAOYSA-N citric acid Chemical compound OC(=O)CC(O)(C(O)=O)CC(O)=O KRKNYBCHXYNGOX-UHFFFAOYSA-N 0.000 claims abstract description 440
- 238000001914 filtration Methods 0.000 claims abstract description 37
- 238000001728 nano-filtration Methods 0.000 claims abstract description 28
- 239000012466 permeate Substances 0.000 claims abstract description 18
- 239000012452 mother liquor Substances 0.000 claims description 35
- 238000000855 fermentation Methods 0.000 claims description 28
- 230000004151 fermentation Effects 0.000 claims description 28
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 claims description 24
- 239000008103 glucose Substances 0.000 claims description 24
- 238000011084 recovery Methods 0.000 claims description 22
- 239000000047 product Substances 0.000 claims description 19
- 238000002425 crystallisation Methods 0.000 claims description 16
- 230000008025 crystallization Effects 0.000 claims description 16
- 229930091371 Fructose Natural products 0.000 claims description 15
- 239000005715 Fructose Substances 0.000 claims description 15
- RFSUNEUAIZKAJO-ARQDHWQXSA-N Fructose Chemical compound OC[C@H]1O[C@](O)(CO)[C@@H](O)[C@@H]1O RFSUNEUAIZKAJO-ARQDHWQXSA-N 0.000 claims description 15
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 14
- 239000007787 solid Substances 0.000 claims description 13
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 13
- 239000012465 retentate Substances 0.000 claims description 12
- 239000013078 crystal Substances 0.000 claims description 9
- 238000011144 upstream manufacturing Methods 0.000 claims description 9
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 8
- 150000001768 cations Chemical class 0.000 claims description 8
- 239000012263 liquid product Substances 0.000 claims description 8
- 238000001035 drying Methods 0.000 claims description 7
- 150000001720 carbohydrates Chemical class 0.000 claims description 6
- 239000002904 solvent Substances 0.000 claims description 6
- 238000004587 chromatography analysis Methods 0.000 claims description 5
- 238000004090 dissolution Methods 0.000 claims description 5
- 238000004064 recycling Methods 0.000 claims description 5
- 239000011347 resin Substances 0.000 claims description 5
- 229920005989 resin Polymers 0.000 claims description 5
- PXRKCOCTEMYUEG-UHFFFAOYSA-N 5-aminoisoindole-1,3-dione Chemical compound NC1=CC=C2C(=O)NC(=O)C2=C1 PXRKCOCTEMYUEG-UHFFFAOYSA-N 0.000 claims description 4
- 238000005341 cation exchange Methods 0.000 claims description 4
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims description 3
- 235000011941 Tilia x europaea Nutrition 0.000 claims description 3
- 238000005349 anion exchange Methods 0.000 claims description 3
- FNAQSUUGMSOBHW-UHFFFAOYSA-H calcium citrate Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O.[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O FNAQSUUGMSOBHW-UHFFFAOYSA-H 0.000 claims description 3
- 239000001354 calcium citrate Substances 0.000 claims description 3
- 150000001860 citric acid derivatives Chemical class 0.000 claims description 3
- 238000010828 elution Methods 0.000 claims description 3
- 238000000605 extraction Methods 0.000 claims description 3
- 239000004571 lime Substances 0.000 claims description 3
- 238000001556 precipitation Methods 0.000 claims description 3
- 235000013337 tricalcium citrate Nutrition 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 2
- 238000005342 ion exchange Methods 0.000 claims description 2
- 238000000638 solvent extraction Methods 0.000 claims description 2
- 125000002791 glucosyl group Chemical group C1([C@H](O)[C@@H](O)[C@H](O)[C@H](O1)CO)* 0.000 claims 3
- 235000010633 broth Nutrition 0.000 description 28
- 239000012528 membrane Substances 0.000 description 14
- 238000005119 centrifugation Methods 0.000 description 8
- 238000012360 testing method Methods 0.000 description 8
- WQZGKKKJIJFFOK-VFUOTHLCSA-N beta-D-glucose Chemical compound OC[C@H]1O[C@@H](O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-VFUOTHLCSA-N 0.000 description 7
- 239000002699 waste material Substances 0.000 description 7
- 239000012535 impurity Substances 0.000 description 6
- GUBGYTABKSRVRQ-QKKXKWKRSA-N Lactose Natural products OC[C@H]1O[C@@H](O[C@H]2[C@H](O)[C@@H](O)C(O)O[C@@H]2CO)[C@H](O)[C@@H](O)[C@H]1O GUBGYTABKSRVRQ-QKKXKWKRSA-N 0.000 description 5
- 125000000129 anionic group Chemical group 0.000 description 5
- 239000008101 lactose Substances 0.000 description 5
- 150000001450 anions Chemical class 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 4
- 238000012216 screening Methods 0.000 description 3
- 239000002028 Biomass Substances 0.000 description 2
- JLVVSXFLKOJNIY-UHFFFAOYSA-N Magnesium ion Chemical compound [Mg+2] JLVVSXFLKOJNIY-UHFFFAOYSA-N 0.000 description 2
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 2
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 description 2
- 229930006000 Sucrose Natural products 0.000 description 2
- 150000001413 amino acids Chemical class 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 229940041514 candida albicans extract Drugs 0.000 description 2
- -1 citrate ions Chemical class 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 150000004676 glycans Chemical class 0.000 description 2
- 230000003179 granulation Effects 0.000 description 2
- 238000005469 granulation Methods 0.000 description 2
- 229910001425 magnesium ion Inorganic materials 0.000 description 2
- 229920001282 polysaccharide Polymers 0.000 description 2
- 239000005017 polysaccharide Substances 0.000 description 2
- 239000011591 potassium Substances 0.000 description 2
- 229910001414 potassium ion Inorganic materials 0.000 description 2
- 108090000765 processed proteins & peptides Proteins 0.000 description 2
- 230000008929 regeneration Effects 0.000 description 2
- 238000011069 regeneration method Methods 0.000 description 2
- 239000005720 sucrose Substances 0.000 description 2
- 239000001117 sulphuric acid Substances 0.000 description 2
- 235000011149 sulphuric acid Nutrition 0.000 description 2
- 239000012138 yeast extract Substances 0.000 description 2
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 1
- 241000228245 Aspergillus niger Species 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- 101100340769 Homo sapiens ILF2 gene Proteins 0.000 description 1
- 102000049951 Nuclear Factor 45 Human genes 0.000 description 1
- 108700031302 Nuclear Factor 45 Proteins 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 239000003463 adsorbent Substances 0.000 description 1
- 239000002518 antifoaming agent Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910001424 calcium ion Inorganic materials 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 239000013065 commercial product Substances 0.000 description 1
- 239000012809 cooling fluid Substances 0.000 description 1
- 238000011026 diafiltration Methods 0.000 description 1
- 239000000284 extract Substances 0.000 description 1
- 239000000706 filtrate Substances 0.000 description 1
- 229910052602 gypsum Inorganic materials 0.000 description 1
- 239000010440 gypsum Substances 0.000 description 1
- 239000003456 ion exchange resin Substances 0.000 description 1
- 229920003303 ion-exchange polymer Polymers 0.000 description 1
- 238000001032 ion-exclusion chromatography Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 244000005700 microbiome Species 0.000 description 1
- 230000003278 mimic effect Effects 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 102000004196 processed proteins & peptides Human genes 0.000 description 1
- 102000004169 proteins and genes Human genes 0.000 description 1
- 108090000623 proteins and genes Proteins 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 239000001509 sodium citrate Substances 0.000 description 1
- NLJMYIDDQXHKNR-UHFFFAOYSA-K sodium citrate Chemical compound O.O.[Na+].[Na+].[Na+].[O-]C(=O)CC(O)(CC([O-])=O)C([O-])=O NLJMYIDDQXHKNR-UHFFFAOYSA-K 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
- 239000012265 solid product Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/42—Separation; Purification; Stabilisation; Use of additives
Definitions
- This invention relates to a process for treating a liquid. It also relates to a process for recovering citric acid.
- a process for treating a liquid comprises: (a) subjecting a liquid containing solution, citric acid as well as a less desirable component having a similar molecular weight to citric acid, to nanofiltration in a filtration step; and (b) obtaining, from the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution.
- nanofiltration will normally involve contacting the liquid with a nanofiltration membrane. Nanofiltration will naturally also separate the citric acid from any component with a molecular weight which is significantly greater than that of citric acid.
- the molecular weight or relative molecular mass of the less desirable component may be within 20% of that of citric acid.
- the molecular weight of the less desirable component may be within 10%, and even within about 7%, of that of citric acid.
- the molecular weight of the second component may range from 0.8MW-1.2MW, e.g., 0.9MW-1.1MW, or even about 0.93MW—about 1.07MW, where MW is the molecular weight of the citric acid.
- the process will have particular, but not necessarily exclusive, application in the treatment of fermentation broth to separate citric acid present therein as a fermentation product from residual glucose and/or fructose, thereby recovering the citric acid. It has been found that, with the process of the invention, the citric acid can be separated from residual glucose and/or fructose as well as other impurities such as medium and higher molecular weight by-products such as peptide and polysaccharides, produced by fermentation microorganisms, and which can be undesirable. In other words, the process has specific application in the recovery of citric acid from a fermentation broth, particularly from a clarified citric acid fermentation broth.
- the clarified citric acid fermentation broth can typically be that obtained by fermenting a carbohydrate feedstock to produce citric acid-rich fermentation broth and waste solids, and separating the broth from the solids.
- Citric acid has a similar molecular mass to glucose and fructose and can preferentially be separated from glucose and/or fructose in the process according to the invention, as a result of its greater permeability through the nanofiltration membrane as compared to that of glucose and/or fructose.
- the filtration step may be carried out at a concentration of the citric acid in the broth of 5%-30% by mass, preferably 10%-20% by mass, and the nanofiltration may be carried out at a temperature of 10° C.-100° C., preferably 20° C.-50° C.
- the pressure drop across the nanofiltration membrane will depend on the nature of the membrane and one the nature of the citric acid and the less desirable component to be separated and can be established by routine experimentation.
- the clarified citric acid fermentation broth may, before the filtration step, be subjected to cation exchange to remove cations, such as potassium and magnesium ions, therefrom.
- the process may include further treating the citric acid solution from the filtration step to purify it and/or to obtain a more concentrated citric acid fraction, or solid citric acid or a derivative of citric acid, such as sodium citrate.
- the citric acid solution from the filtration step may be purified by anion exchange, e.g., to remove traces of anionic impurities, and/or by contacting it with activated carbon to remove traces of organic matter.
- the purified citric acid solution may then be concentrated. This may include treating the solution to obtain solid pure citric acid and residual mother liquor.
- the concentration may include subjecting the solution to at least one evaporation and crystallization sequence.
- the concentration may include passing the solution sequentially through an evaporator; a first crystallizer; a first centrifuge; optionally a dissolution tank, a second crystallizer and a second centrifuge; and producing mother liquor in the first centrifuge and, when present, in the second centrifuge.
- a portion of the mother liquor from the second centrifuge, when present, may then be recycled to the first crystallizer, while the mother liquor from the fist centrifuge is withdrawn.
- the contacting of the citric acid solution with the activated carbon hereinbefore referred to may instead, or additionally, be effected after the purified citric acid solution has been concentrated at least partially, e.g., after it has passed through the evaporator.
- the process may also include: (i) recycling a portion of the mother liquor from the first centrifuge to upstream of the evaporator; and/or (ii) withdrawing at least a portion of the mother liquor from the first centrifuge as a liquid product; and/or (iii) drying and/or granulating at least a portion of the mother liquor from the first centrifuge to obtain a solid citric acid/carbohydrate product; and/or (iv) treating at least a portion of the mother liquor from the first centrifuge, in a recovery step, to recover citric acid for recycle, or citrate salts as product.
- this citric acid may be recycled to upstream and/or downstream of the nanofiltration step.
- the treatment in the recovery step may then comprise one of the following: calcium citrate precipitation by adding lime thereto and redissolving with sulphuric acid; solvent extraction of citric acid utilizing a suitable solvent, followed by re-extraction of citric acid from the solvent into water using concentration differences or heating; ion exchange using a resin which selectively adsorbs citric acid, followed by elution; or various types of chromatography.
- At least a portion of the retentate from the filtration step may be withdrawn as a liquid product. Instead, or additionally, at least a portion of the retentate from the filtration step may be dried or granulated to obtain a solid citric acid product. Instead, or additionally, at least a portion of the retentate from the filtration step may be treated in a citric acid recovery step, which may then be the same as the citric acid recovery step, hereinbefore described, to recover citric acid or a derivative thereof therefrom.
- the retentate from the filtration step may be combined with the mother liquor from the first centrifuge for withdrawal as a liquid product and/or for drying or granulating and/or for treatment in a recovery step, as hereinbefore described.
- a process for recovering citric acid comprises subjecting a clarified citric acid fermentation broth to nanofiltration in a filtration step to obtain as a permeate, a purified citric acid solution.
- the clarified citric acid fermentation broth may, before the filtration step, be subjected to cation exchange as hereinbefore described.
- the citric acid solution from the filtration step may be treated further to purify it and/or to obtain a more concentrated citric acid fraction, or solid citric acid or a derivative of citric acid, as hereinbefore described.
- the filtration step may also be as hereinbefore described.
- FIG. 1 is a flow diagram of a process for treating a fermentation broth.
- reference numeral 10 generally indicates a process according to the invention for treating a fermentation broth.
- the process 10 includes a cation exchanger stage 32 .
- a clarified citric acid fermentation broth feed line 30 leads from a fermentation stage (not shown) into the stage 32 .
- a regeneration water/acid flow line 34 also leads into the stage 32 , while a waste product withdrawal line 36 leads from the stage 32 .
- a flow line 38 also leads from the stage 32 .
- the flow line 38 leads to a nanofiltration step or stage 40 , with a waste product or retentate withdrawal line 42 leading from the stage 40 .
- a cleaning water/base and diafiltration flow line 41 leads into the nanofiltration stage 40 .
- a filtrate flow line 44 leads from the stage 40 to an anion exchanger 46 , with a regeneration water/base flow line 48 leading into the exchanger 46 .
- a waste product withdrawal line 49 leads from the stage 46 , while a flow line 50 leads from the exchanger 46 to an activated carbon bed stage 52 .
- a flow line 54 leads from the stage 52 to an evaporation stage 56 , with a steam flow line 58 leading into the stage 56 .
- a condensate line 60 leads from the stage 56 .
- a flow line 62 leads from the stage 56 to a first crystallization stage 64 .
- a flow line 66 leads from the crystallization stage 64 to a first centrifugation stage 68 .
- a flow line 70 leads from the first centrifugation stage 68 to a dissolution tank 72 , with a water make-up line 74 leading into the tank 72 .
- a flow line 76 leads from the tank 72 to a second crystallization stage 78 , with a flow line 80 leading from the second crystallization stage 78 to a second centrifugation stage 82 .
- a mother liquor recycle line 84 leads from the stage 82 to the crystallization stages 64 , 78 .
- a flow line 86 leads from the second centrifugation stage 82 to a drier 88 , with a flow line 90 leading from the drier 88 to a screening stage 92 .
- a solid product withdrawal line 94 leads from the screening stage 92 .
- the second crystallization stage 78 and second centrifugation stage 82 are used to improve crystal quality and are optional; they can be dispensed with, if necessary.
- a mother liquor withdrawal line 96 leads from the first centrifugation stage 68 .
- the line 96 can be routed back to the flow line 50 for recycling a portion of the mother liquor.
- the flow line 96 can lead to a drying and granulation stage 100 .
- the flow line 96 can lead to a recovery stage 102 .
- a waste product withdrawal line 104 leads from the stage 102 .
- a citric acid recycle line 106 leads from the stage 102 back to upstream and/or downstream of stage 40 .
- first, second, third and fourth embodiments described hereinbefore are optional and can be used individually, or a combination of two or more of the embodiments can be used, as desired.
- a flow line 108 can, if desired, lead from the flow line 42 to the flow line 96 upstream of the product withdrawal stage 98 , the drying and granulation stage 100 , and/or the citric acid recovery unit 102 .
- clarified citric acid fermentation broth produced in known fashion in the fermentation stage, passes to the cation exchanger 32 where it is contacted with a suitable resin to remove cations such as calcium and sodium ions. If these ions are not removed they would form complexes with the citrate ions and be retained by the nanofilter element in the subsequent filtration stage 40 leading to product losses.
- the resin bed can be regenerated in known fashion, when required.
- the broth then passes to the nanofiltration stage 40 where the citric acid is separated, by contacting the broth with a nanofiltration membrane, from glucose, fructose, and higher molcular weight components in the broth such as protein, residual anti-foaming agents, sucrose, peptides and polysaccharides which thus form the retentate. Smaller molecules as well as some anions pass through the nanofiltration membrane and, together with the citric acid and most of the water, form the permeate.
- the permeate is thus in the form of a purified citric acid solution in which the ratio or proportion of the concentration of citric acid to that of glucose and fructose is greater than the ratio or proportion or the concentration of citric acid to that of the glucose and fructose in the feed to the stage 40 .
- glucose and fructose which have a similar molecular weight ( 180 ) to citric acid ( 192 ) are separated therefrom.
- the permeate from the filtration stage 40 passes to the anionic exchanger 46 where anionic impurities are removed and withdrawn.
- the resin bed of the anionic exchanger 46 is regenerated in known fashion, when required.
- the citric acid containing solution from the exchanger 46 passes to the activated carbon bed stage 52 where traces of organics are removed.
- the citric acid solution thereafter passes to the evaporator where it is concentrated, using steam, from a concentration of 10% to 20% by mass citric acid, typically up to about 65% to 80% by mass citric acid. Condensate from the evaporation stage 56 leaves along the line 60 .
- the concentrated citric acid solution passes to the first crystallization stage 64 where crystallization of the citric acid is effected.
- the stream then passes to the first centrifuge stage 68 where the citric acid crystals are separated from the mother liquor.
- the citric acid crystals pass into the dissolution tank 72 where they are redissolved in make-up water, whereafter they are recrystallized in the second crystallization stage 78 to improve crystal quality.
- the make-up water may be obtained from any suitable source, such as process condensate, a dilute citric acid stream, or the like.
- the stream from the crystallization stage 78 passes to the second centrifugation stage 82 where mother liquor is again removed.
- the moist crystals pass to the drier 88 , with dried crystals passing to the screening stage 92 .
- Dried solid substantially pure citric acid crystals are withdrawn along the flow line 94 .
- the crystallization stages 64 , 78 typically comprise known crystallizers, and will thus include ancillary equipment normally associated therewith such as steam feed/condensate outlet lines, cooling fluid lines, and the like.
- Mother liquor from the first centrifugation stage 68 is withdrawn along the flow line 96 .
- a portion of this mother liquor can be recycled to the activated carbon bed 52 .
- this mother liquor can be withdrawn as a liquid product in the stage 98 .
- this mother liquor can be dried and granulated in the stage 100 to obtain a citric acid/carbohydrate solid commercial product.
- this mother liquor can pass to the recovery stage 102 .
- Waste product, e.g., glucose and trace impurities, from the recovery stage 102 is withdrawn, while if pure citric acid is recovered, it may be recycled to upstream or downstream of stage 40 ; or if citrate salts are recovered, they will be recovered as product.
- a portion of the retentate from the nanofiltration stage 40 can be routed, by means of the flow line 108 , to the stream 96 and then routed to any of the optional stages 98 , 100 and/or 102 , If desired, to recover residual citric acid or a derivative thereof present in this stream.
- the recovery stag 102 may utilize calcium citrate precipitation after lime addition; followed by sulphuric acid addition to form citric acid as well as the by product gypsum, to recover citric acid.
- the citric acid in the mother liquor may, in the stage 102 , be extracted using a suitable solvent, followed by re-extraction citric acid from the solvent phase into water using concentration differences or with the aid of heat.
- the recovery stage 102 may comprise an ion exchange resin which selectively adsorbs citric acid, with elution of the product into water thereafter taking place.
- the citric acid recovery stage may comprise various types of chromatography.
- Clarified citric acid fermentation broth containing 18.4 weight percent citric acid can be obtained by fermentating various cultures, such as Aspergillus niger , on a purified carbohydrate feedstock, and filtering off the resultant biomass.
- the broth leaving the fermenters can contain 0.2% (w/w) unfermented glucose or 0.2% (w/w) unfermented fructose.
- the clarified citric acid fermentation broth is then subjected to cation exchange, to remove cations such as potassium and magnesium ions.
- the clarified decationized citric acid fermentation broth is then contacted with a nanofiltration membrane, and 80 or more percent of the citric acid transfers to the permeate, which contains up to 18 weight percent citric acid.
- the permeate also contains the following from the clarified decationized citric acid fermentation broth: a portion of the glucose and fructose, anions, cations, amino acids and sucrose, as well as 80 or more percent of the water.
- the retentate can be treated in a citric acid recovery step, using the UOPTM Citric Acid SorbexTM Process (CitrexTM), to recover the remaining citric acid,
- the permeate from the nanofiltration step can be subjected to anion exchange, to remove traces of anionic impurities, followed by contacting with activated carbon, to remove traces of organics.
- the permeate can thereafter be concentrated by evaporation in an evaporator, followed by a first crystallizer, a first centrifuge, a dissolution tank, a second crystallizer and a second centrifuge; with 20% by weight of the mother liquor from the second centrifuge being recycled to the first crystallizer, while the mother liquor from the first centrifuge is withdrawn.
- the process can include (i) recycling 25% (w/w) of the mother liquor from the first centrifuge to upstream of the evaporator, (ii) withdrawing 10.0% (w/w) of the mother liquor from the first centrifuge as a liquid product, (iii) drying and granulating 21.6% (w/w) of the mother liquor from the first centrifuge to obtain a solid citric acid/carbohydrate product; and (iv) treating the remainder of the mother liquor from the first centrifuge, together with 80% (w/w) of the nanofiltration retentate, using the UOPTM Citric Acid SorbexTM Process (CitrexTM) process (this process revolves around any one of various chromatographic techniques, such as ion exclusion chromatography, whereby citric acid is separated from the feed stream by selective adsorption onto a solid adsorbent) in a recovery step, to recover citric acid which can be recycled to downstream of the nanofiltration step.
- the extract can contain, from the feed stream, on a weight to weight basis: 92% of the citric acid, 1% of the glucose and fructose, 1% of the cations and anions, 1% of the amino acids and biomass, negligible sulfuric acid, and 44% of the water from both the feed stream and the desorbent stream.
- the balance of the above mentioned components report to the raffinate (waste stream).
- This feature thus provides the basis for a simple and efficient means of separating citric acid from high and medium molecular weight impurities as well as removing most of the residual glucose, in respect of fermentation broth.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Preparation Of Compounds By Using Micro-Organisms (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
A process for treating a liquid comprising subjecting a liquid containing, in solution, citric acid as well as a less desirable component having a similar molecular weight to citric acid, to nanofiltration in a filtration step. From the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution, is obtained.
Description
- This application is a continuation of copending PCT Application PCT/US96/12160, filed Sep. 12, 1995, designating the United States, which claims priority from South African application no. 94/0711, filed Sep. 12, 1994, both of which are incorporated herein by reference.
- This invention relates to a process for treating a liquid. It also relates to a process for recovering citric acid.
- According to a first aspect of the invention, there is provided a process for treating a liquid, which process comprises: (a) subjecting a liquid containing solution, citric acid as well as a less desirable component having a similar molecular weight to citric acid, to nanofiltration in a filtration step; and (b) obtaining, from the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution.
- In other words, there is a greater degree of rejection of the less desirable component than of the citric acid in the filtration step. The nanofiltration will normally involve contacting the liquid with a nanofiltration membrane. Nanofiltration will naturally also separate the citric acid from any component with a molecular weight which is significantly greater than that of citric acid.
- The molecular weight or relative molecular mass of the less desirable component may be within 20% of that of citric acid. For example, the molecular weight of the less desirable component may be within 10%, and even within about 7%, of that of citric acid. In other words, the molecular weight of the second component may range from 0.8MW-1.2MW, e.g., 0.9MW-1.1MW, or even about 0.93MW—about 1.07MW, where MW is the molecular weight of the citric acid.
- The Applicant believes that the process will have particular, but not necessarily exclusive, application in the treatment of fermentation broth to separate citric acid present therein as a fermentation product from residual glucose and/or fructose, thereby recovering the citric acid. It has been found that, with the process of the invention, the citric acid can be separated from residual glucose and/or fructose as well as other impurities such as medium and higher molecular weight by-products such as peptide and polysaccharides, produced by fermentation microorganisms, and which can be undesirable. In other words, the process has specific application in the recovery of citric acid from a fermentation broth, particularly from a clarified citric acid fermentation broth.
- The clarified citric acid fermentation broth can typically be that obtained by fermenting a carbohydrate feedstock to produce citric acid-rich fermentation broth and waste solids, and separating the broth from the solids.
- Citric acid has a similar molecular mass to glucose and fructose and can preferentially be separated from glucose and/or fructose in the process according to the invention, as a result of its greater permeability through the nanofiltration membrane as compared to that of glucose and/or fructose.
- The filtration step may be carried out at a concentration of the citric acid in the broth of 5%-30% by mass, preferably 10%-20% by mass, and the nanofiltration may be carried out at a temperature of 10° C.-100° C., preferably 20° C.-50° C. The pressure drop across the nanofiltration membrane will depend on the nature of the membrane and one the nature of the citric acid and the less desirable component to be separated and can be established by routine experimentation.
- The clarified citric acid fermentation broth may, before the filtration step, be subjected to cation exchange to remove cations, such as potassium and magnesium ions, therefrom.
- The process may include further treating the citric acid solution from the filtration step to purify it and/or to obtain a more concentrated citric acid fraction, or solid citric acid or a derivative of citric acid, such as sodium citrate.
- Thus, the citric acid solution from the filtration step may be purified by anion exchange, e.g., to remove traces of anionic impurities, and/or by contacting it with activated carbon to remove traces of organic matter.
- The purified citric acid solution may then be concentrated. This may include treating the solution to obtain solid pure citric acid and residual mother liquor. The concentration may include subjecting the solution to at least one evaporation and crystallization sequence. In particular, the concentration may include passing the solution sequentially through an evaporator; a first crystallizer; a first centrifuge; optionally a dissolution tank, a second crystallizer and a second centrifuge; and producing mother liquor in the first centrifuge and, when present, in the second centrifuge. A portion of the mother liquor from the second centrifuge, when present, may then be recycled to the first crystallizer, while the mother liquor from the fist centrifuge is withdrawn. The contacting of the citric acid solution with the activated carbon hereinbefore referred to may instead, or additionally, be effected after the purified citric acid solution has been concentrated at least partially, e.g., after it has passed through the evaporator.
- The process may also include: (i) recycling a portion of the mother liquor from the first centrifuge to upstream of the evaporator; and/or (ii) withdrawing at least a portion of the mother liquor from the first centrifuge as a liquid product; and/or (iii) drying and/or granulating at least a portion of the mother liquor from the first centrifuge to obtain a solid citric acid/carbohydrate product; and/or (iv) treating at least a portion of the mother liquor from the first centrifuge, in a recovery step, to recover citric acid for recycle, or citrate salts as product.
- When the process includes treating at least a portion of the mother liquid from the first centrifuge in a recovery step to recover citric acid, this citric acid may be recycled to upstream and/or downstream of the nanofiltration step. The treatment in the recovery step may then comprise one of the following: calcium citrate precipitation by adding lime thereto and redissolving with sulphuric acid; solvent extraction of citric acid utilizing a suitable solvent, followed by re-extraction of citric acid from the solvent into water using concentration differences or heating; ion exchange using a resin which selectively adsorbs citric acid, followed by elution; or various types of chromatography.
- At least a portion of the retentate from the filtration step may be withdrawn as a liquid product. Instead, or additionally, at least a portion of the retentate from the filtration step may be dried or granulated to obtain a solid citric acid product. Instead, or additionally, at least a portion of the retentate from the filtration step may be treated in a citric acid recovery step, which may then be the same as the citric acid recovery step, hereinbefore described, to recover citric acid or a derivative thereof therefrom.
- The retentate from the filtration step may be combined with the mother liquor from the first centrifuge for withdrawal as a liquid product and/or for drying or granulating and/or for treatment in a recovery step, as hereinbefore described.
- According to a second aspect of the invention, there is provided a process for recovering citric acid, which process comprises subjecting a clarified citric acid fermentation broth to nanofiltration in a filtration step to obtain as a permeate, a purified citric acid solution.
- The clarified citric acid fermentation broth may, before the filtration step, be subjected to cation exchange as hereinbefore described. The citric acid solution from the filtration step may be treated further to purify it and/or to obtain a more concentrated citric acid fraction, or solid citric acid or a derivative of citric acid, as hereinbefore described. The filtration step may also be as hereinbefore described.
- The invention will now be described by way of example, with reference to the accompanying simplified flow diagram in FIG. 1 of a process according to the invention for treating a fermentation broth, and with reference to the non-limiting examples.
- FIG. 1 is a flow diagram of a process for treating a fermentation broth.
- In FIG. 1,
reference numeral 10 generally indicates a process according to the invention for treating a fermentation broth. - The
process 10 includes acation exchanger stage 32. A clarified citric acid fermentationbroth feed line 30 leads from a fermentation stage (not shown) into thestage 32. A regeneration water/acid flow line 34 also leads into thestage 32, while a wasteproduct withdrawal line 36 leads from thestage 32. Aflow line 38 also leads from thestage 32. - The
flow line 38 leads to a nanofiltration step orstage 40, with a waste product or retentatewithdrawal line 42 leading from thestage 40. A cleaning water/base anddiafiltration flow line 41 leads into thenanofiltration stage 40. Afiltrate flow line 44 leads from thestage 40 to ananion exchanger 46, with a regeneration water/base flow line 48 leading into theexchanger 46. A wasteproduct withdrawal line 49 leads from thestage 46, while aflow line 50 leads from theexchanger 46 to an activatedcarbon bed stage 52. - A
flow line 54 leads from thestage 52 to anevaporation stage 56, with asteam flow line 58 leading into thestage 56. Acondensate line 60 leads from thestage 56. Aflow line 62 leads from thestage 56 to afirst crystallization stage 64. Aflow line 66 leads from thecrystallization stage 64 to afirst centrifugation stage 68. Aflow line 70 leads from thefirst centrifugation stage 68 to adissolution tank 72, with a water make-upline 74 leading into thetank 72. Aflow line 76 leads from thetank 72 to asecond crystallization stage 78, with aflow line 80 leading from thesecond crystallization stage 78 to asecond centrifugation stage 82. A motherliquor recycle line 84 leads from thestage 82 to thecrystallization stages flow line 86 leads from thesecond centrifugation stage 82 to adrier 88, with aflow line 90 leading from thedrier 88 to ascreening stage 92. A solidproduct withdrawal line 94 leads from thescreening stage 92. - The
second crystallization stage 78 andsecond centrifugation stage 82 are used to improve crystal quality and are optional; they can be dispensed with, if necessary. - A mother
liquor withdrawal line 96 leads from thefirst centrifugation stage 68. - In a first embodiment of the invention, the
line 96 can be routed back to theflow line 50 for recycling a portion of the mother liquor. - In a second embodiment of the invention, the
flow line 96 call lead to a suitable liquidproduct withdrawal stage 98. - In a third embodiment of The invention, the
flow line 96 can lead to a drying andgranulation stage 100. - In a fourth embodiment of the invention, the
flow line 96 can lead to arecovery stage 102. A wasteproduct withdrawal line 104 leads from thestage 102. A citric acid recycleline 106 leads from thestage 102 back to upstream and/or downstream ofstage 40. - It will be appreciated that the first, second, third and fourth embodiments described hereinbefore are optional and can be used individually, or a combination of two or more of the embodiments can be used, as desired.
- A flow line108 can, if desired, lead from the
flow line 42 to theflow line 96 upstream of theproduct withdrawal stage 98, the drying andgranulation stage 100, and/or the citricacid recovery unit 102. - In use, clarified citric acid fermentation broth, produced in known fashion in the fermentation stage, passes to the
cation exchanger 32 where it is contacted with a suitable resin to remove cations such as calcium and sodium ions. If these ions are not removed they would form complexes with the citrate ions and be retained by the nanofilter element in thesubsequent filtration stage 40 leading to product losses. The resin bed can be regenerated in known fashion, when required. - The broth then passes to the
nanofiltration stage 40 where the citric acid is separated, by contacting the broth with a nanofiltration membrane, from glucose, fructose, and higher molcular weight components in the broth such as protein, residual anti-foaming agents, sucrose, peptides and polysaccharides which thus form the retentate. Smaller molecules as well as some anions pass through the nanofiltration membrane and, together with the citric acid and most of the water, form the permeate. The permeate is thus in the form of a purified citric acid solution in which the ratio or proportion of the concentration of citric acid to that of glucose and fructose is greater than the ratio or proportion or the concentration of citric acid to that of the glucose and fructose in the feed to thestage 40. Thus, in thefiltration stage 40, glucose and fructose, which have a similar molecular weight (180) to citric acid (192) are separated therefrom. - The permeate from the
filtration stage 40 passes to theanionic exchanger 46 where anionic impurities are removed and withdrawn. The resin bed of theanionic exchanger 46 is regenerated in known fashion, when required. - The citric acid containing solution from the
exchanger 46 passes to the activatedcarbon bed stage 52 where traces of organics are removed. - The citric acid solution thereafter passes to the evaporator where it is concentrated, using steam, from a concentration of 10% to 20% by mass citric acid, typically up to about 65% to 80% by mass citric acid. Condensate from the
evaporation stage 56 leaves along theline 60. The concentrated citric acid solution passes to thefirst crystallization stage 64 where crystallization of the citric acid is effected. The stream then passes to thefirst centrifuge stage 68 where the citric acid crystals are separated from the mother liquor. The citric acid crystals pass into thedissolution tank 72 where they are redissolved in make-up water, whereafter they are recrystallized in thesecond crystallization stage 78 to improve crystal quality. The make-up water may be obtained from any suitable source, such as process condensate, a dilute citric acid stream, or the like. The stream from thecrystallization stage 78 passes to thesecond centrifugation stage 82 where mother liquor is again removed. The moist crystals pass to the drier 88, with dried crystals passing to thescreening stage 92. Dried solid substantially pure citric acid crystals are withdrawn along theflow line 94. - The crystallization stages64, 78 typically comprise known crystallizers, and will thus include ancillary equipment normally associated therewith such as steam feed/condensate outlet lines, cooling fluid lines, and the like.
- Mother liquor from the
first centrifugation stage 68 is withdrawn along theflow line 96. - In a first embodiment, a portion of this mother liquor can be recycled to the activated
carbon bed 52. - In a second embodiment, at least a portion of this mother liquor can be withdrawn as a liquid product in the
stage 98. - In a third embodiment, at least a portion of this mother liquor can be dried and granulated in the
stage 100 to obtain a citric acid/carbohydrate solid commercial product. - In a fourth embodiment, at least a portion of this mother liquor can pass to the
recovery stage 102. Waste product, e.g., glucose and trace impurities, from therecovery stage 102 is withdrawn, while if pure citric acid is recovered, it may be recycled to upstream or downstream ofstage 40; or if citrate salts are recovered, they will be recovered as product. A portion of the retentate from thenanofiltration stage 40 can be routed, by means of the flow line 108, to thestream 96 and then routed to any of theoptional stages - In one version of the invention, the
recovery stag 102 may utilize calcium citrate precipitation after lime addition; followed by sulphuric acid addition to form citric acid as well as the by product gypsum, to recover citric acid. - In another version, the citric acid in the mother liquor may, in the
stage 102, be extracted using a suitable solvent, followed by re-extraction citric acid from the solvent phase into water using concentration differences or with the aid of heat. - In yet another version, the
recovery stage 102 may comprise an ion exchange resin which selectively adsorbs citric acid, with elution of the product into water thereafter taking place. - In yet a further version of the invention, the citric acid recovery stage may comprise various types of chromatography.
- The Applicant believes that with the
process 10, citric acid can be recovered effectively and at relatively low cost. In addition it is believed that theprocess 10 will be relatively simple to operate. - The following examples are provided for illustrative purposes, and are not intended to limit the scope of the invention as claimed herein. Any variations in the exemplified methods which occur to the skilled artisan are intended to fall within the scope of the present invention.
- The
process 10 of the invention was simulated theoretically as follows. - Clarified citric acid fermentation broth containing 18.4 weight percent citric acid, can be obtained by fermentating various cultures, such asAspergillus niger, on a purified carbohydrate feedstock, and filtering off the resultant biomass. The broth leaving the fermenters can contain 0.2% (w/w) unfermented glucose or 0.2% (w/w) unfermented fructose.
- The clarified citric acid fermentation broth is then subjected to cation exchange, to remove cations such as potassium and magnesium ions.
- The clarified decationized citric acid fermentation broth is then contacted with a nanofiltration membrane, and 80 or more percent of the citric acid transfers to the permeate, which contains up to 18 weight percent citric acid. The permeate also contains the following from the clarified decationized citric acid fermentation broth: a portion of the glucose and fructose, anions, cations, amino acids and sucrose, as well as 80 or more percent of the water. The retentate can be treated in a citric acid recovery step, using the UOP™ Citric Acid Sorbex™ Process (Citrex™), to recover the remaining citric acid,
- The permeate from the nanofiltration step can be subjected to anion exchange, to remove traces of anionic impurities, followed by contacting with activated carbon, to remove traces of organics.
- The permeate can thereafter be concentrated by evaporation in an evaporator, followed by a first crystallizer, a first centrifuge, a dissolution tank, a second crystallizer and a second centrifuge; with 20% by weight of the mother liquor from the second centrifuge being recycled to the first crystallizer, while the mother liquor from the first centrifuge is withdrawn.
- The process can include (i) recycling 25% (w/w) of the mother liquor from the first centrifuge to upstream of the evaporator, (ii) withdrawing 10.0% (w/w) of the mother liquor from the first centrifuge as a liquid product, (iii) drying and granulating 21.6% (w/w) of the mother liquor from the first centrifuge to obtain a solid citric acid/carbohydrate product; and (iv) treating the remainder of the mother liquor from the first centrifuge, together with 80% (w/w) of the nanofiltration retentate, using the UOP™ Citric Acid Sorbex™ Process (Citrex™) process (this process revolves around any one of various chromatographic techniques, such as ion exclusion chromatography, whereby citric acid is separated from the feed stream by selective adsorption onto a solid adsorbent) in a recovery step, to recover citric acid which can be recycled to downstream of the nanofiltration step.
- In the Citrex recovery step, which uses a very dilute solution of sulfuric acid as desorbent, the extract can contain, from the feed stream, on a weight to weight basis: 92% of the citric acid, 1% of the glucose and fructose, 1% of the cations and anions, 1% of the amino acids and biomass, negligible sulfuric acid, and 44% of the water from both the feed stream and the desorbent stream. The balance of the above mentioned components report to the raffinate (waste stream).
- In a simulation of the nanofiltration step or
stage 40, laboratory scale tests were conducted on simulated citric acid fermentation broths coding, by mass, 18-19% citric acid, 1% lactose, 0.2% glucose and 0.05% yeast extract. The yeast extract was used to mimic other components normally present in commercial formation broths. Each test was conducted with a pair of membranes, by treating a batch of the simulated broth. - Concentrations of each of the components were measured, and the rejections calculated. The results are set out in Tables 1. 2 and 3 (all percentages are on a mass bases).
TABLE 1 Results of Nanofiltration Test 1 Experiment 1 Citric Acid % Lactose % Glucose % Feed 18.8 0.88 0.22 Permeate- Membrane A 12.3 0.01 0.03 Permeate- Membrane B 14.6 0.18 0.09 Concentrate 29 2.1 0.47 -
TABLE 2 Results of Nanofiltration Test 2 Experiment 2 Citric acid % Lactose % Glucose % Feed 18 0.88 0 Permeate- Membrane A 11.4 0.01 none Permeate- Membrane B 11.7 0.05 0.07 Concentrate 28 1.9 0.38 -
TABLE 3 Rejections of the two membranes Rejections expressed as percentages Citric acid Lactose % Glucose % Filmtec NF45 Test 1 34.6 98.9 86.4 Test 2 36.7 98.9 >90 MPKW MPF23 Test 1 22.3 79.5 59.1 Test 2 35.0 94.3 65.0 - One of the key parameters in nanofiltration is the rejection. For the simulated citric acid fermentation broths, it was expected, according to literature and product information, that membrane rejections would be in the order lactose>citric acid>glucose, However, as can be seen from Table 3, the actual rejection of citric acid was surprisingly found to be lower than that of glucose.
- This feature thus provides the basis for a simple and efficient means of separating citric acid from high and medium molecular weight impurities as well as removing most of the residual glucose, in respect of fermentation broth.
- It is to be appreciated that, together with the citric acid, other more valuable fermentation products can be separated from the glucose.
Claims (20)
1. A process for treating a liquid, which process comprises
subjecting a liquid containing, in solution, citric acid as well as a less desirable component having a molecular weight similar to that of citric acid, to nanofiltration in a filtration step;
obtaining, from the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution; and
concentrating the permeate by subjecting it to crystallization without treating the permeate to remove the remaining less desirable component prior to the crystallization.
2. A process according to claim 1 , wherein the molecular weight of the less desirable component is within 20% of that of citric acid.
3. A process according to claim 2 , wherein the molecular weight of the less desirable component is within 10% of that of citric acid.
4. A process of claim 1 , wherein the molecular weight of the less desirable component is less than that of citric acid.
5. A process according to claim 4 , wherein the liquid is clarified citric acid fermentation broth so that the permeate is a purified citric acid solution, and the less desirable component is glucose and/or fructose.
6. A process according to claim 5 , wherein the filtration step is carried out at a concentration of the citric acid in the broth of 5% -30% by mass, and wherein the filtration is carried out at a temperature of 10° C.-100° C.
7. A process according to claim 5 , wherein the clarified citric acid fermentation broth is, before the filtration step, subjected to cation exchange to remove cations therefrom.
8. A process according to claim 5 , wherein the citric acid solution from the filtration step is purified by anion exchange and/or by contacting it with activated carbon.
9. A process according to claim 5 , which includes concentrating the purified citric acid solution by subjecting it to crystallization.
10. A process according to claim 9 , wherein the concentration is effected by passing the purified citric acid solution sequentially through an evaporator; a first crystallizer; a first centrifuge; optionally, a dissolution tank, a second crystallizer and a second centrifuge; and producing mother liquor in the first centrifuge and, when present, in the second centrifuge, with a portion of the mother liquor from the second centrifuge then being recycled to the first crystallizer, while the mother liquor from the first centrifuge is withdrawn.
11. A process according to claim 10 , which includes (i) recycling a portion of the mother liquor from the first centrifuge to upstream of the evaporator; and/or (ii) withdrawing at least a portion of the mother liquid from the first centrifuge as a liquid product; and/or (iii) drying and grating at least a portion of the mother liquor from the first centrifuge to obtain a solid citric acid/carbohydrate product; and/or (iv) treating at least a portion of the mother liquor from the first centrifuge, in a recovery step, to recover citric acid for recycle, or citrate salts as product.
12. A process according to claim 10 , which includes treating at least a portion of the mother liquid from the first centrifuge, in a recovery step, to recover citric acid, with the citric acid being recycled to upstream and/or downstream of the nanofiltration step, and with treatment in the recovery step comprising one of the following: calcium citrate precipitation by adding lime thereto and redissolving with sulfuric acid; solvent extraction of citric acid utilizing a suitable solvent, followed by re-extraction of citric acid from the solvent into water using concentration differences or heating; ion exchange using a resin which selectively adsorbs citric acid, followed by elution; or chromatography.
13. A process according to claim 12 , which includes (i) withdrawing at least a portion of the retentate from the filtration step as a liquid product, and/or (ii) drying or granulating at least a portion of the retentate from the filtration step to obtain a solid citric acid product, and/or (iii) treating at least a portion of the retentate from the filtration step in a citric acid recovery step.
14. A process for treating a liquid, which process comprises
subjecting a liquid containing, in solution, citric acid as well as a less desirable component having a similar molecular weight to citric acid, to filtration in a filtration step;
obtaining, from the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution;
concentrating the permeate by subjecting it to crystallization in at least one crystallizer, with citric acid crystals and mother liquor being produced in the crystallizer;
separating the citric acid crystals from the mother liquor;
treating at least a portion of the mother liquor to recover citric acid therefrom; and
recycling at least a portion of the recovered citric acid to upstream and/or down stream of the filtration step.
15. A process according to claim 14 , wherein the molecular weight of the less desirable component is within 20% of that of citric acid, and wherein the liquid is clarified citric acid fermentation broth so that the permeate is a purified citric acid solution, and the less desirable component is glucose and/or fructose.
16. A process according to claim 15 , wherein the filtration is nanofiltration.
17. A process according to claim 15 , wherein recovery of the citric acid is effected by means of chromatography.
18. A process according to claim 15 , wherein the molecular weight of the less desirable component is less than that of citric acid.
19. A process for treating a liquid, which process comprises
subjecting a liquid containing, in solution, citric acid as well as a less desirable component having a molecular weight less than that of citric acid, to nanofiltration in a filtration step; and
obtaining, from the filtration step, a permeate in which the ratio of the concentration of the citric acid to that of the less desirable component is greater than the ratio of the concentration of the citric acid to that of the less desirable component in the solution.
20. The process of claim 19 wherein the less desirable component is glucose and/or fructose.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/225,016 US20030000894A1 (en) | 1994-09-12 | 2002-08-21 | Process for treating liquid |
US10/943,378 US20050054881A1 (en) | 1994-09-12 | 2004-09-17 | Process for treating a liquid |
Applications Claiming Priority (7)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
ZA94/0711 | 1994-09-12 | ||
ZA947011 | 1994-09-12 | ||
PCT/US1996/012160 WO1997005307A1 (en) | 1995-07-28 | 1996-07-24 | Process for modifying porosity in sheet made from flash spinning olefin polymer |
US08/811,564 US5965028A (en) | 1994-09-12 | 1997-03-04 | Process for treating a liquid |
US34794299A | 1999-07-06 | 1999-07-06 | |
US65692600A | 2000-09-07 | 2000-09-07 | |
US10/225,016 US20030000894A1 (en) | 1994-09-12 | 2002-08-21 | Process for treating liquid |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US65692600A Continuation | 1994-09-12 | 2000-09-07 |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/943,378 Continuation US20050054881A1 (en) | 1994-09-12 | 2004-09-17 | Process for treating a liquid |
Publications (1)
Publication Number | Publication Date |
---|---|
US20030000894A1 true US20030000894A1 (en) | 2003-01-02 |
Family
ID=27123494
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US08/811,564 Expired - Fee Related US5965028A (en) | 1994-09-12 | 1997-03-04 | Process for treating a liquid |
US10/225,016 Abandoned US20030000894A1 (en) | 1994-09-12 | 2002-08-21 | Process for treating liquid |
US10/943,378 Abandoned US20050054881A1 (en) | 1994-09-12 | 2004-09-17 | Process for treating a liquid |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US08/811,564 Expired - Fee Related US5965028A (en) | 1994-09-12 | 1997-03-04 | Process for treating a liquid |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US10/943,378 Abandoned US20050054881A1 (en) | 1994-09-12 | 2004-09-17 | Process for treating a liquid |
Country Status (1)
Country | Link |
---|---|
US (3) | US5965028A (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9352222B2 (en) * | 2002-12-10 | 2016-05-31 | Sony Interactive Entertainment America Llc | System and method for capturing text for an online application |
FI120590B (en) * | 2005-10-28 | 2009-12-15 | Danisco Sweeteners Oy | Difference method |
FI20065363A0 (en) * | 2006-05-30 | 2006-05-30 | Danisco Sweeteners Oy | Difference method |
US8357302B2 (en) * | 2010-08-02 | 2013-01-22 | Ampac Fine Chemicals Llc | Reaction systems with incorporated chromatography units for enhanced product recovery |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5032686A (en) * | 1988-06-06 | 1991-07-16 | Roquette Freres | Method for the recovery of citric acid from a liquor containing the same |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE680595C (en) * | 1931-01-07 | 1939-09-01 | Charles Pfizer & Company | Process for the preparation of crystallized citric acid |
US3799840A (en) * | 1969-01-22 | 1974-03-26 | Takeda Chemical Industries Ltd | Method for producing citric acid |
US4113771A (en) * | 1971-04-07 | 1978-09-12 | Ethyl Corporation | Process for the purification of citric acid |
JPS5231033B2 (en) * | 1972-05-03 | 1977-08-12 | ||
AR207952A1 (en) * | 1973-04-26 | 1976-11-22 | Takeda Chemical Industries Ltd | PROCESS FOR OBTAINING CRITALS OF MONOSODIUM CITRATE MONOHYDRATED |
DE2450670A1 (en) * | 1974-10-25 | 1976-04-29 | Benckiser Gmbh Joh A | PROCESS FOR SEPARATION OF CITRATE OR CITRIC ACID FROM FERMENTATION SOLUTIONS |
DE2543333C2 (en) * | 1975-09-29 | 1985-06-20 | Degussa Ag, 6000 Frankfurt | Process for the simultaneous production of pure grape acid and meso-tartaric acid |
DD232723A5 (en) * | 1984-02-03 | 1986-02-05 | ���k�K@���������@����k�� | PROCESS FOR OBTAINING CITRIC ACID |
US5104799A (en) * | 1990-10-05 | 1992-04-14 | Haarmann & Reimer | Method for the production of granular citric acid and salts thereof |
US5045459A (en) * | 1990-10-05 | 1991-09-03 | Haarmann & Reimer Corp. | Method for the production of granular citric acid |
US5681728A (en) * | 1995-06-07 | 1997-10-28 | Chronopol, Inc. | Method and apparatus for the recovery and purification of organic acids |
US5532148A (en) * | 1995-08-30 | 1996-07-02 | Ntec, Inc. | Process for producing of citric acid and monovalent citrate salts |
-
1997
- 1997-03-04 US US08/811,564 patent/US5965028A/en not_active Expired - Fee Related
-
2002
- 2002-08-21 US US10/225,016 patent/US20030000894A1/en not_active Abandoned
-
2004
- 2004-09-17 US US10/943,378 patent/US20050054881A1/en not_active Abandoned
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5032686A (en) * | 1988-06-06 | 1991-07-16 | Roquette Freres | Method for the recovery of citric acid from a liquor containing the same |
Also Published As
Publication number | Publication date |
---|---|
US20050054881A1 (en) | 2005-03-10 |
US5965028A (en) | 1999-10-12 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
KR101828634B1 (en) | Process for removing, isolating and purifying dicarboxylic acids | |
US9422220B2 (en) | Method for purifying carboxylic acids from fermentation broths | |
JP6303017B2 (en) | Method for purifying aromatic amino acids | |
CN103964989B (en) | The system that amino acid is continuously isolated and purified from the aqueous solution of the alkali metal salt of amino acid | |
JPS6329999B2 (en) | ||
US11685759B2 (en) | Method for obtaining crystalline 2′-fucosyllactose | |
Omwene et al. | Bio-based succinic acid recovery by ion exchange resins integrated with nanofiltration/reverse osmosis preceded crystallization | |
JP3013995B2 (en) | Method for separating 2-keto-L-gulonic acid from fermentation medium | |
CN114853823A (en) | Method for extracting thymidine | |
US5965028A (en) | Process for treating a liquid | |
EP0781264B1 (en) | Process for recovering citric acid | |
JPH02275835A (en) | Method for recovering citric acid from solution containing citric acid | |
US4496703A (en) | Process for recovering amino acids from protein hydrolysates | |
KR20020022789A (en) | Process for purifying 2-keto-l-gulonic acid | |
WO2012013793A1 (en) | Method for recovering an auxiliary used in a fermentation procedure for producing a product | |
RU2410435C1 (en) | Method of extracting l-lysine from culture fluid | |
JP2001011034A (en) | Separation and recovery of optically active amino acid and optically active amino acid amide | |
MXPA97001863A (en) | Process for the recovery of citr acid | |
US10549238B2 (en) | Methods of regenerating a resin used to decolorize a biomass feedstream and related systems | |
CN117902974A (en) | Method for recovering succinic acid and malic acid from succinic acid mother liquor | |
CN118027115A (en) | Purification method of fucosyllactose | |
CN117105796A (en) | Method for recovering glutamic acid, ammonium sulfate and pyroglutamic acid from glutamic acid isoelectric mother solution | |
JPH04183395A (en) | Method for separating and purifying mannitol | |
JPH02169524A (en) | Recovery of organic acid | |
JPS63130580A (en) | Purification of tryptophan |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |
|
AS | Assignment |
Owner name: USTECH, INC., OHIO Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:REILLY INDUSTRIES, INC.;REEL/FRAME:015732/0448 Effective date: 20050214 |