DE1014116B - Process for the production of glutamic acid - Google Patents

Description

GERMAN

The invention relates to a method for obtaining glutamic acid from the in the refining of Sugar from sugar beet waste eyes obtained in such a pure form that they are converted to monosodium glutamate suitable. In the present novel process, in particular the Steffen filtrate or the concentrated filtrate is used as the raw material applied.

In the food industry, glutamic acid is widely used in the form of monosodium glutamate used, which is able to improve the aroma of many foods. So far there are numerous methods for Production and recovery of glutamic acid from Steffen's filtrates have been proposed. At all in these processes there are considerable difficulties in obtaining the glutamic acid in high yields and to purify the crude glutamic acid to such an extent that it is converted into monosodium glutamate really high purity product and is obtained in acceptable yields.

In previous processes, the effective separation of the contaminating inorganic salts has been achieved the hydrolyzate of Steffen's filtrate and the purification of the crude glutamic acid cause considerable difficulties prepares. In particular, lower yields of monosodium glutamate are obtained when the solutions the same certain impurities, e.g. B. contain calcium compounds that prevent crystal growth and thereby retard and decrease the yields of monosodium glutamate. Particular difficulties are in the processing of the waste eye of .Steffenschen Filtrate and the recovery of monosodium glutamate from this occurred because of significant amounts of Impurities in the form of inorganic salts result in the crystallization of monosodium glutamate from them Prevent lyes and reduce the monosodium glutamate yield.

It is known to hydrolyse protein substances that split off glutamic acid with hydrochloric acid and that Then hydrolyzate for the purpose of precipitating alkaline earths with <"> To add sodium carbonate - or hydrolysis and alkaline earth precipitation by treating the starting substances to be carried out with sulfuric acid in one step.

In contrast, the invention generally consists in first precipitating the calcium present in the mixtures from which glutamic acid is to be obtained from the mixture containing glutamic acid in the form of a calcium salt which is insoluble in water, for example calcium carbonate or calcium phosphate. For this purpose, the mixture containing glutamic acid is mixed with an alkali metal carbonate or alkali metal phosphate and the precipitate obtained is separated off from the solution. The reagent is intended to be used prior to the process of manufacture using an alkali hydroxide
of glutamic acid

Applicant:
International

Minerals & Chemical Corporation,
Chicago, 111. (V. St. A.)

Representative: Dr.-Ing. H. Ruschke, Berlin-Friedenau,

and Dipl.-Ing. K. Grentzenberg, Munich 13,

Ainmillerstr. 26, patent attorneys

Ralph W. Shafor, Los Gatos, Calif.,

and Erik V. Heegaard, Menlo Park, Calif. (V. St. Α.),

have been named as inventors

Hydrolysis can be added to the mixture containing glutamic acid.

By adding one of the above reagents to precipitate or remove the water-insoluble calcium salt of the calcium from the mixture containing glutamic acid becomes that caused by incomplete crystallization Loss of monosodium glutamate restricted to a minimum. The second major advantage of the invention lies in the fact that the addition of the alkali metal carbonate or phosphate inherently reduces the effectiveness of the subsequent Hydrolysis with the alkali hydroxide increased.

According to one embodiment, sodium carbonate is added to the Steffen's filtrate and the precipitated Calcium salt e.g. filtered off. The Steffensche filtrate can be before the clarification, concentration or especially before the Hydrolysis can be treated with sodium carbonate.

In a particular embodiment of the invention, sodium carbonate is used with the concentrated Steffenschen The filtrate is mixed, its pn and specific gravity, depending on the origin of the liquor, in a fairly wide range Limits can vary, but in general the specific gravity is around 1.32 and the pn between about 9.0 and 10.5, eliminating the insoluble salts are practically completely precipitated. This salt precipitate is then removed from the Steffen's filtrate e.g. filtered off. The filtrate obtained is then hydrolyzed with alkali metal hydroxide in a manner known per se and the glutamic acid is obtained from the hydrolyzate in the usual manner.

709 658/427

The insoluble salt forming reagent is generally either in solid form or in aqueous form Solution added. If it is preferably added as an aqueous solution, there is no need to stir. if but the reagent or the like is added in the form of a powder, must be stirred so that it dissolves. Man uses between 4.5 and 27 kg of alkali salt per ton of concentrated Steffenschen to precipitate the calcium Filtrate.

After adding the precipitating reagent, the mixture is left to stand until the insoluble calcium salt is practically dissolved has completely deposited, or the mixture is heated in order to accelerate this deposition. If you want to accelerate the separation of the insoluble salts, it is best to heat the mixture until boiling. If necessary, the mixture is also stirred. The density of the mixture that makes up the calcium is to be deposited does not need to be specially adjusted; the formation of the insoluble calcium salts but occurs faster in dilute solutions than in very concentrated solutions.

Example I.

Into concentrated Steffen's filtrate, which contained about 4.2 kg per tonne of calcium oxide, varying amounts were given 15 ° / _o aqueous sodium carbonate solution. These mixtures were then heated to about 80 ° and then allowed to cool to room temperature. The precipitate was filtered off. The table below shows the extent to which the calcium has been removed from the concentrated Steffen's filtrates with the addition of increasing amounts of sodium carbonate. acid was allowed to crystallize from the resulting solution at a pn between about 2.5 and 4.0, the glutamic acid was up to 6% purer and the yield of glutamic acid was 2 to 2.5% higher than when the Steffen's filtrate was treated previous procedure.

Example II

Concentrated Stiff's filtrate with 0.18% CaO and 58.3% dry matter was mixed with trisodium phosphate in various amounts and that Mixture stirred until practically complete conversion with the calcium. The precipitated calcium phosphate was filtered off and the calcium content of the filtrate determined. As can be seen from the results, the calcium completely remove by this treatment.

To the Steffen's filtrate Calcium content V ^ d, IL j. U. III ~
distance given amount
Na ₃ PO ₁ -12H ₂ O after
treatment in "/ ο kg / t in CaO 61 3.7 0.07 83 7.3 0.03 100 14.7 0.00 100 22.0 0.00

Calcium removal in% off
concentrated Steffen's filtrates

Added Distant Calcium The rest sodium
carbonate CaO distance CaO kg / t kg / t in % kg / t 5 2.2 52 2.0 10 3.3 76 0.9 15th 3.7 88 0.5 20th 3.9 92 0.3 25th 4.1 96 0.1

35

40

45

When the stiff's filtrate from which the calcium is removed was hydrolyzed, the inorganic salts were precipitated and separated and the glutamine

Claims (3)

PATENT CLAIMS: 1. Process for the production of glutamic acid, in which Steffensches filtrate with an alkali hydroxide hydrolyzed and the glutamic acid is obtained from the hydrolyzate obtained, characterized in that that the calcium present in the Steffens' filtrate before hydrolysis with a Alkali carbonate or alkali phosphate falls and the resulting precipitate from the Steffen's filtrate separates. 2. The method according to claim 1, characterized in that sodium carbonate is used to precipitate the calcium or sodium phosphate is used. 3. The method according to claim 1 or 2, characterized in that one is used to precipitate the calcium between 4.5 and 27 kg of sodium carbonate per ton of concentrated Steffen's filtrate is used. Considered publications:
German Patent No. 301,499;
Austrian Patent No. 17 574;
U.S. Patent No. 2,375,165. ® 709 658/427 8.57