# US 8,772,440 B2 · Process for manufacturing lactic acid > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,772,440 B2 - Document ID: US8772440B2 - Status: Granted - Kind: B2 - Application number: 13/577,398 - Filed: 2011-02-08 - Published: 2013-08-29 - Granted: 2014-07-08 - Earliest claimed: 2010-02-08 - Assignees: Purac Biochem B.V. - Applicants: Peter Johannes Marie Baets; Willem Jacob Groot - Inventors: Peter Johannes Marie Baets; Willem Jacob Groot - Web page: https://patentgrep.com/patent/US8772440B2 ## CPC - C07D 319/12: not condensed with other rings - C07C 51/412: {by conversion of the acids, their salts, esters or anhydrides with the same carboxylic acid part} - C07C 51/44: by distillation - C07C 51/48: by liquid-liquid treatment - C08G 63/06: derived from hydroxycarboxylic acids - C12P 7/56: Lactic acid - Y02A 20/124: Water desalination - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - C12P: FERMENTATION OR ENZYME-USING PROCESSES TO SYNTHESISE A DESIRED CHEMICAL COMPOUND OR COMPOSITION OR TO SEPARATE OPTICAL ISOMERS FROM A RACEMIC MIXTURE {(brewing of beer C12C; producing vinegar C12J; producing specific peptides or proteins C07K; producing enzymes C12N9/00; DNA or RNA concerning genetic engineering, vectors, e.g. plasmids, or their isolation, preparation or purification C12N15/00; measuring or testing processes involving enzymes or microorganisms C12Q; measuring or testing processes involving nucleic acid amplification reactions C12Q1/6844; fermentation processes to form a food composition, A21 or A23; compounds in general, see the relevant compound class, e.g. C01, C07)} - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE ## Abstract A process for the preparation of lactic acid includes: a) providing an aqueous medium comprising magnesium lactate; b) adding to the aqueous medium a monovalent base to form an aqueous medium comprising a water soluble monovalent lactate salt and a solid magnesium base; c) separating the magnesium base from the aqueous medium; d) adjusting the concentration of the monovalent lactate salt in the aqueous medium, e) subjecting the aqueous medium to water-splitting electrodialysis, to produce a first solution comprising monovalent base and a second solution comprising lactic acid and monovalent lactate salt, the electrodialysis being carried out to a partial conversion of 40 to 98 mole %; f) separating the second solution into lactic acid and a solution comprising the monovalent lactate salt by vapour-liquid separation; g) recycling the solution of step f) comprising the monovalent lactate salt to step d). ## Claims ### Claim 1 A process for the preparation of lactic acid comprising the: a) providing an aqueous medium comprising magnesium lactate; b) adding to the aqueous medium comprising magnesium lactate a monovalent base to form an aqueous medium comprising a water soluble monovalent lactate salt and a solid magnesium base; c) separating the magnesium base from the aqueous medium comprising the water soluble monovalent lactate salt; d) adjusting the concentration of the monovalent lactate salt in the aqueous medium to a value between 10 and 30 wt. %, e) subjecting the aqueous medium comprising the monovalent lactate salt to water-splitting electrodialysis, to produce a first solution comprising monovalent base and a second solution comprising lactic acid and monovalent lactate salt, the electrodialysis being carried out to a partial conversion of 40 to 98 mole %; f) separating the second solution comprising lactic acid and monovalent lactate salt into lactic acid and a solution comprising the monovalent lactate salt by vapour-liquid separation; g) recycling the solution of step f) comprising the monovalent lactate salt to step d). ### Claim 2 (depends on 1) The process according to claim 1, wherein the vapour-liquid separation comprises distillation. ### Claim 3 (depends on 1) The process according to claim 1, wherein the electrodialysis is carried out to a partial conversion of 40 to 95 mole %. ### Claim 4 (depends on 3) The process according to claim 3, wherein the electrodialysis is carried out to a partial conversion of about 85 mole %. ### Claim 5 (depends on 1) The process according to claim 1, wherein concentration of the monovalent lactate salt in the aqueous medium of d) is adjusted to a value between 20 and 25 wt. %. ### Claim 6 (depends on 1) The process according to claim 1, wherein the first solution comprising the monovalent base produced by the water-splitting electrodialysis of step e) is recycled to step b). ### Claim 7 (depends on 1) The process according to claim 1, wherein the water-splitting electrodialysis is carried out in an electrodialysis apparatus provided with a cation exchange membrane and a bipolar membrane. ### Claim 8 (depends on 1) The process according to claim 1, wherein the aqueous medium comprising the magnesium lactate is provided by fermentation, wherein a carbohydrate source is fermented by means of a micro-organism to form lactic acid, a magnesium base being added as neutralising agent during fermentation to provide the magnesium lactate. ### Claim 9 (depends on 8) The process according to claim 8, wherein the magnesium base is magnesium hydroxide. ### Claim 10 (depends on 8) The process according to claim 8, wherein the aqueous medium comprising the magnesium lactate is subjected to a separation step to remove microbial cell matter prior to step b). ### Claim 11 (depends on 1) The process according to claim 1, wherein the monovalent base in step b) comprises a cation that is a sodium, potassium, lithium, ammonium, monoalkylammonium, dialkylammonium, trialkylammonium or tetraalkylammonium cation. ### Claim 12 (depends on 1) The process according to claim 1, wherein the lactic acid obtained after the separation step f) comprises at least 95 wt. % of lactic acid. ### Claim 13 (depends on 1) A process for the preparation of lactide and/or polylactic acid, comprising preparing lactic acid using the process according to claim 1 and reacting the lactic acid to form lactide and/or polylactic acid. ### Claim 14 (depends on 1) The process according to claim 1, wherein the vapour-liquid separation comprises distillation carried out in a vacuum distillation unit. ### Claim 15 (depends on 1) The process according to claim 1, wherein the electrodialysis is carried out to a partial conversion of 50 to 95 mole %. ### Claim 16 (depends on 1) The process according to claim 1, wherein the electrodialysis is carried out to a partial conversion of 60 to 95 mole %. ### Claim 17 (depends on 1) The process according to claim 1, wherein the electrodialysis is carried out to a partial conversion of 80 to 90 mole %. ### Claim 18 (depends on 1) The process according to claim 1, wherein the monovalent base in step b) comprises a cation that is a sodium or potassium cation. ### Claim 19 (depends on 1) The process according to claim 1, wherein the monovalent base in step b) comprises a cation that is a sodium cation. ### Claim 20 (depends on 1) The process according to claim 1, wherein the lactic acid obtained after the separation step f) comprises at least 97 wt. % of lactic acid. ### Claim 21 (depends on 1) The process according to claim 1, wherein the lactic acid obtained after the separation step f) comprises at least 99 wt. % of lactic acid. ### Claim 22 (depends on 1) The process according to claim 1, wherein the lactic acid obtained after the separation step f) comprises at least 99.5 wt. % of lactic acid. ### Claim 23 (depends on 1) The process according to claim 1, wherein the lactic acid obtained after the separation step f) comprises at least 99.9 wt. % of lactic acid.