Process for the recovery of organic acids

Abstract

The present invention relates to a process for the recovery of an organic acid from a fermentation broth which comprises drying the fermentation broth to obtain a dried product, adding the dried product to a lower alcohol in the presence of an acid, and then removing the insoluble material to obtain an organic acid. In accordance with the recovery process of the present invention, organic acids of a high purity can be recovered in high yields from the whole fermentation solution containing various impurities with fewer steps as compared with conventional methods.

1 - 45 . (canceled)  
     
     
         46 . A process for the recovery of an organic acid from a fermentation broth comprising: 
 (a) drying said fermentation broth to obtain a dried product;    (b) adding said dried product to a lower alcohol in the presence of an acid; and    (c) removing insolubles to obtain an organic acid, wherein the process of removing insolubles comprises filtration.    
     
     
         47 . The process of  claim 46 , further comprising removing the insolubles in said fermentation broth prior to the drying of step (a).  
     
     
         48 . The process of  claim 47 , wherein said insolubles are removed prior to the drying step (a) by filtration.  
     
     
         49 . The process of  claim 48 , wherein said insolubles are removed prior to the drying step (a) by ultrafiltration.  
     
     
         50 . The process of  claim 46 , wherein at step (b) the concentration of said organic acid added to said lower alcohol is from about 50 g/L to about 100 g/L.  
     
     
         51 . The process of  claim 46 , wherein at step (a) the process for drying comprises spray drying said fermentation broth.  
     
     
         52 . The process of  claim 46 , wherein the reaction temperature at step (b) is from about 25° C. to about 60° C.  
     
     
         53 . The process of  claim 46 , wherein at step (b) said dried product is added to a lower alcohol prior to the addition of said acid.  
     
     
         54 . The process of  claim 46 , wherein at step (b) about 1.2 equivalents of acid is added.  
     
     
         55 . The process of  claim 46 , wherein at step (b) said lower alcohol is selected from the group consisting of methanol, ethanol, propanol, butanol and glycol.  
     
     
         56 . The process of  claim 46 , wherein at step (b) said acid is selected from the group consisting of sulphuric acid, nitric acid, hydrobromic acid, hydrochloric acid and phosphoric acid.  
     
     
         57 . The process of  claim 56 , wherein at step (b) said acid is sulphuric acid.  
     
     
         58 . The process of  claim 46 , wherein said organic acid comprises lactic acid, 2-keto-L-gulonic acid, citric acid or gluconic acid.  
     
     
         59 . The process of  claim 58 , wherein said organic acid is 2-keto-L-gulonic acid.  
     
     
         60 . The process of  claim 46 , further comprising esterifying said organic acid (c) to the corresponding ester.  
     
     
         61 . A process for the recovery of an organic acid from a fermentation broth comprising: 
 (a) drying said fermentation broth to obtain a dried product;    (b) adding said dried product to a lower alcohol to obtain an alcoholic suspension;    (c) adding an acid to said alcoholic suspension (b); and    (d) removing the insolubles to obtain an organic acid, wherein the process of removing insolubles comprises filtration.    
     
     
         62 . The process of  claim 61 , further comprising removing the insolubles in said fermentation broth prior to the drying of step (a).  
     
     
         63 . The process of  claim 62 , wherein said insolubles are removed prior to the drying step (a) by filtration.  
     
     
         64 . The process of  claim 63 , wherein said insolubles are removed prior to the drying step (a) by ultrafiltration.  
     
     
         65 . The process of  claim 61 , wherein at step (b) the concentration of said organic acid added to said lower alcohol is from about 50 g/L to about 100 g/L.  
     
     
         66 . The process of  claim 61 , wherein at step (a) the process for drying comprises spray drying said fermentation broth.  
     
     
         67 . The process of  claim 61 , wherein the reaction temperature at steps (b) and (c) is from about 25° C. to about 60° C.  
     
     
         68 . The process of  claim 61 , wherein at step (b) said lower alcohol is selected from the group consisting of methanol, ethanol, propanol, butanol and glycol.  
     
     
         69 . The process of  claim 61 , wherein at step (c) about 1.2 equivalents of acid is added.  
     
     
         70 . The process of  claim 61 , wherein at step (c) said acid is selected from the group consisting of sulphuric acid, nitric acid, hydrobromic acid, hydrochloric acid and phosphoric acid.  
     
     
         71 . The process of  claim 70 , wherein at step (c) said acid is sulphuric acid.  
     
     
         72 . The process of  claim 61 , wherein said organic acid comprises lactic acid, 2-keto-L-gulonic acid, citric acid or gluconic acid.  
     
     
         73 . The process of  claim 72 , wherein said organic acid is 2-keto-L-gulonic acid.  
     
     
         74 . The process of  claim 61 , further comprising esterifying said organic acid (d) to the corresponding ester.  
     
     
         75 . A process for the recovery of an organic acid ester from a fermentation broth comprising: 
 (a) drying said fermentation broth to obtain a dried product;    (b) adding said dried product to a lower alcohol in the presence of an acid;    (c) esterifying the free organic acid to the corresponding ester; and    (d) removing insolubles to obtain an organic acid ester, wherein the process of removing insolubles comprises filtration.    
     
     
         76 . The process of  claim 75 , further comprising removing the insolubles in said fermentation broth prior to the drying of step (a).  
     
     
         77 . The process of  claim 76 , wherein said insolubles are removed by filtration.  
     
     
         78 . The process of  claim 77 , wherein said insolubles are removed by ultrafiltration.  
     
     
         79 . The process of  claim 75 , wherein at step (b) the concentration of said organic acid added to said lower alcohol is from about 50 g/L to about 100 g/L.  
     
     
         80 . The process of  claim 75 , wherein at step (a) the process for drying comprises spray drying said fermentation broth.  
     
     
         81 . The process of  claim 75 , wherein the reaction temperature at steps (b) and (c) is from about 25° C. to about 60° C.  
     
     
         82 . The process of  claim 75 , wherein at step (b) said lower alcohol is selected from the group consisting of methanol, ethanol, propanol, butanol and glycol.  
     
     
         83 . The process of  claim 75 , wherein at step (b) about 1.2 equivalents of acid is added.  
     
     
         84 . The process of  claim 75 , wherein at step (b) said acid is selected from the group consisting of sulphuric acid, nitric acid, hydrobromic acid, hydrochloric acid and phosphoric acid.  
     
     
         85 . The process of  claim 84 , wherein at step (b) said acid is sulphuric acid.  
     
     
         86 . The process of  claim 75 , wherein at step (d) the process for removing insolubles comprises filtration.  
     
     
         87 . The process of  claim 75 , wherein said organic acid comprises lactic acid, 2-keto-L-gulonic acid, citric acid or gluconic acid.  
     
     
         88 . The process of  claim 87 , wherein said organic acid is 2-keto-L-gulonic acid.  
     
     
         89 . A process for the recovery of an organic acid from a fermentation broth comprising: 
 (a) drying said fermentation broth to obtain a dried product, wherein said drying occurs without prior removal of insolubles from said organic acid- containing fermentation broth;    (b) adding said dried product (a) to a lower alcohol, selected from the group consisting of methanol, ethanol, propanol, butanol or glycol, in the presence of an acid; and    (c) removing insolubles to obtain an organic acid, where the process of removing insolubles comprises filtration.    
     
     
         90 . The process of  claim 89 , wherein at step (b) the concentration of said organic acid added to said lower alcohol is from 50 g/L to 100 g/L.  
     
     
         91 . The process of  claim 89 , wherein at step (a) the process for drying comprises spray drying said fermentation broth.  
     
     
         92 . The process of  claim 89 , wherein the temperature at step (b) is from 25° C. to 60° C.  
     
     
         93 . The process of  claim 89 , wherein at step (b) 1.2 equivalents of acid is added.  
     
     
         94 . The process of  claim 89 , wherein at step (b) said acid is selected from the group consisting of sulphuric acid, nitric acid, hydrobromic acid, hydrochloric acid and phosphoric acid.  
     
     
         95 . The process of  claim 94 , wherein at step (b) said acid is sulphuric acid.  
     
     
         96 . The process of  claim 89 , wherein said organic acid comprises lactic acid, 2-keto-L-gulonic acid, citric acid or gluconic acid.  
     
     
         97 . The process of  claim 96 , wherein said organic acid is 2-keto-L-gulonic acid.  
     
     
         98 . The process of  claim 89 , further comprising esterifying said organic acid (c) to the corresponding ester.