DE102009019248A1 - Processing organic acid from fermentation broth in which biomass is separated and filtrate is treated with acid to obtain a mixture, comprises applying the mixture on chromatography resin, rinsing with mobile phase and obtaining fractions - Google Patents

Abstract

Method for processing organic acid from fermentation broth, where the pH-value during the fermentation is adjusted by the addition of a base, the biomass from the fermentation broth is separated and the resulting filtrate is treated with acid to obtain a mixture, which releases organic acid and further components, comprises: (a) applying the mixture on chromatography resin that is equilibrated with a suitable mobile phase and comprises one or more interconnected columns; (b) rinsing the columns with the mobile phase; and (c) obtaining different fractions. Method for processing organic acid from fermentation broth, where the pH-value during the fermentation is adjusted by the addition of a base that binds as a salt to the resulting organic acid, the biomass from the fermentation broth is separated and the resulting filtrate is treated with acid to obtain a mixture, which releases organic acid and further components, comprises: (a) applying the mixture on a chromatography resin (a continuously operated simulated moving bed chromatography) that is equilibrated with a suitable mobile phase and comprises one or more interconnected columns; (b) rinsing the columns with the mobile phase; and (c) obtaining different fractions, in which each components of the mixture are collected separately from each other based on their different retention times.

Description

The The invention relates to a process for working up organic acids from fermenter broths using chromatographic methods. The invention aims in particular at the conventional Chromatography methods for the purification of organic acids to optimize by using Simulated Continuous Chromatography Moving Bed is performed.

in the Generally, to control the pH during the Fermentation usually added to a base, which is the resulting Acid binds as salt. For example, calcium hydroxide is used for neutralization in the fermentative production of citric acid and lactic acid.

By Acidifying the fermentation broth, for example with sulfuric acid, you get the free organic Acid and it precipitates gypsum. For the further work-up and concentration of the organic acid now, if possible, all other components be removed. These are the residues of the used for fermentation Substances like sugar, amino acids and others as well as the sulphation and the cation of the base used in the fermentation, such as sodium or ammonium.

in the classic lactic acid process becomes neutralization the resulting lactic acid calcium carbonate or calcium hydroxide used.

at The workup of the broth makes you the low solubility of calcium sulfate, which is used in the acidification with Sulfuric precipitates as precipitate and by Filtration can be separated. As the accumulating calcium sulfate in this method are significant and the resulting plaster often difficult to be recycled and thus usually needs to be disposed of intensively according to alternative procedures sought, which make the separation more effective.

Examples Such alternative methods of the prior art are the Electrodialysis and various extraction methods. Also the esterification the acid with a short-chain alcohol with subsequent Distillation was tested. All enumerated So far, procedures have not been successful in large-scale plants.

It has also been found that lactic acid can be isolated from the mixture described above, that is to say, for example, a fermentation broth acidified with sulfuric acid, which in addition to free lactic acid still contains ammonium and sulfate ions, can be isolated by means of chromatographic methods. DE 69815369 T2 describes, inter alia, the separation of lactic acid from aqueous mixtures by adsorption to a solid adsorbent, preferably a solid adsorbent is used here, which adsorbs lactic acid versus lactate. In particular, according to the above document weak anion exchangers for lactic acid isolation come into question.

are the affinity differences of the molecules to be separated very small, a change of mobile or stationary ranges Phase often fails to effectively separate the to be separated To reach molecules. The problem of generating different Retention times of the molecules to be separated must therefore other way to be solved. It is also an ion exchange process on a large scale much too expensive and expensive.

The The object of the invention is therefore the conventional Process of processing organic acids so to optimize that above-mentioned problems that primarily with the high accumulating amounts of calcium sulfate in the workup of the Fermentation broth are connected to be solved. The target product is the organic acid selectively be isolated from the salt-containing fermenter broth, the also other components, such as residual sugar, dyes and others May contain substances.

This is achieved by a process for working up organic acids from fermenter broths, with the pH during the fermentation is adjusted by the addition of a base which is the resulting organic acid as a salt binds the biomass separated from the fermentation broth is treated, and the resulting filtrate is treated with acid, creating a mixture that releases the released organic acid and other components by adding the mixture a chromatographic resin equilibrated with a suitable mobile phase, a continuously operated Simulated Moving Bed Chromatography, comprising one or more interconnected columns, is applied, the column rinsed with the mobile phase , and various fractions are obtained in which individual components the mixture separated due to different retention times collected from each other.

Under Circumstances, the resulting filtrate after separation The biomass of a filtration are subjected to as possible remove all particles. In particular, would be suitable a microfiltration, but also an ultrafiltration, whereby in usually also a partial discoloration of the resulting Filtrats can be achieved.

The technique of Simulated Moving Bed Chromatography represents an improved version of High Performance Liquid Chromatography For example, a succession of columns interconnected by valves produces an infinitely extensible stationary phase, which drastically improves the separation of the molecules to be separated, since a large number of theoretical plates can be formed. In this case, the sample inlet device and the analyte outlet device are moved continuously.

It could be one for organic acids, in particular Lactic acid, suitable chromatography resin can be found This allows a very pure acid fraction to obtain without this being very diluted or it comes to larger product losses. It acts it is a weakly basic anion exchanger, such as. B. LEWATIT MP62, 64 or Amberlite FPA 51; 53 or 54. Preferably the mobile phase is water.

at the organic acid to be isolated in the process it is citric acid or lactic acid. there this acid is in a purity of 80-98% obtained by the individual components of the mixture on the basis of the characteristic Retention times are separated. The salts remain in the second fraction and may further work up be supplied.

The The present invention will be described below with reference to an embodiment described in detail.

A filtered fermenter broth from a lactic acid fermentation was concentrated by evaporation. The lactic acid content was then 20.6% by mass. By acidification with sulfuric acid The solution contained 10.5 mass% sulfate ions which were removed had to be. For this, the mixture was simulated over Moving Bed Chromatography given, consisting of 8 interconnected Columns and filled with 3 liters of resin per column were. In this example, Amberlite FPA 53 resin was the company Rohm & Haas used. To control the lactic acid content was a refractometer used. As a result of the separation, about 85% of lactic acid could be obtained in a sulfate-free fraction. The concentration the lactic acid in this fraction was 10% by mass.

• • effektive Isolierung der organischen Säuren möglich
• • die organischen Säuren können nach ihrer Chiralität aufgetrennt werden

Advantages resulting from the invention:

• • effective isolation of organic acids possible
• • The organic acids can be separated according to their chirality

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 69815369 T2 [0007]

Claims (4)

Process for working up organic acids from fermenter broths, wherein the pH is adjusted during the fermentation by the addition of a base which binds the resulting organic acid as salt, the biomass is separated from the fermentation broth, and the resulting filtrate is treated with acid to form a mixture containing the released organic acid and other components, characterized in that the mixture is applied to a chromatography resin equilibrated with a suitable mobile phase, a continuously operated Simulated Moving Bed Chromatography comprising one or more interconnected columns • rinsing the column with the mobile phase, • obtaining different fractions in which individual components of the mixture are collected separately due to different retention times. Method according to claim 1, characterized in that that it is the organic acid to be isolated is citric acid or lactic acid. Method according to claim 2, characterized in that that the acid to be isolated with a purity of 80-98% is obtained. Method according to one of claims 1 to 3, characterized in that as the mobile phase preferably water is used.