KR890000536B1 - Process for collecting glutamic acid from glutamic acid mother broth - Google Patents

Abstract

A method for collecting glutamic acid is presented. The characteristic of the method is adjustment of glutamate culture broth to 25-35 Be' and pH 0.3-1.5 using H2SO4 to collect glutamic acid.

Description

How to Recover Glutamic Acid from Glutamic Acid Separation Solution

The accompanying drawings are process diagrams of the present invention.

The present invention relates to a method for recovering glutamic acid from the remaining filtrate (hereinafter referred to as mother liquor) after recovering and separating the glutamic acid crystals from the glutamic acid fermentation broth.

In the conventional production method of glutamic acid, a crude fermentation solution containing glutamic acid is obtained by molasses as a main ingredient, sulfuric acid is directly added to the fermentation broth, and neutralization crystallization is carried out at isoelectric point to recover crude crystals of glutamic acid or sulfuric acid or hydrochloric acid in glutamic acid fermentation broth. Neutralization crystallization to isoelectric point was added to recover glutamic acid crude crystals, glutamic acid crystals were recovered and separated, and the remaining filtrate was used as an acid decomposition solution or in the manufacture of organic fertilizers and feeds.

However, since it takes a lot of time and expense to produce glutamic acid by microorganisms, efforts have been made to recover glutamic acid from glutamic acid-containing fermentation solution to the maximum. It is being disposed of. Thus, even if glutamic acid is contained in the mother liquor, the reason why it cannot be recovered is that impurities contained in the molasses in the fermentation raw material and impurities remaining in the mother liquor due to inorganic salts used during fermentation (water-soluble inorganic substances, cells, sugars, organic proteins and trace amounts) Elements are known to interfere with the crystallization of glutamic acid, and the most damaging factors among these impurities are water-soluble minerals such as potassium ions (K ⁺ ), calcium ions (Ca ⁺⁺ ), Magnesium ions (Mg ⁺⁺ ) and ammonium ions (NH ₄ ⁺ ) react with sulfuric acid used for pH adjustment during neutralization crystallization even if crystals of glutamic acid are precipitated, resulting in potassium sulfate, calcium sulfate, magnesium sulfate, ammonium sulfate or these It is difficult to separate the glutamic acid and the inorganic salt by forming a double salt of glutamic acid and mixing it into the glutamic acid crystal and coprecipitation. It has been a factor in lowering the rate and purity of glutamic acid.

Therefore, in the present invention, in recovering glutamic acid in the mother liquor, by recovering in the crystal state by coprecipitating the glutamic acid with inorganic salt, only the inorganic salt is removed, thereby recovering the high purity glutamic acid in the mother liquor with high yield which cannot be achieved by the conventional method. It is to provide an improved method.

That is, according to the present invention, the glutamic acid filtrate recovered from the mother liquor treatment process is circulated to glutamic acid fermentation broth mainly containing molasses, neutralized and crystallized to pH 3.2-3.4, and then the crude glutamic acid crystals are recovered and separated. Sodium hexametaphosphate (hereinafter referred to as HMP) is used to concentrate 0.1-0.5g / 1 when the mother liquor is concentrated, and it is concentrated to 1 / 2-1 / 4 under vacuum decompression to cool, crystallize, and separate impurities. From the mother liquor, the glutamic acid crude crystal and the inorganic salt were recovered in a mixed state, and then, 5N-15N sulfuric acid solution was added thereto to adjust the pH to 0.3-1.5, and the concentration was maintained at 28-32 Be '. The solution was cooled and crystallized for 4-8 hours to crystallize the inorganic salt crystals, to coarse crystallization, and to dissolve the glutamic acid crude crystals to separate the glutamic acid and the inorganic salt, respectively. When sulfuric acid is added to the mixed solution of glutamic acid and inorganic salt, glutamic acid is lower than isoelectric point (PH3.2-3.4), so glutamic acid is dissolved and dissolved, and inorganic salt is combined with sulfuric acid, calcium sulfate, potassium sulfate, magnesium sulfate and sulfuric acid. Since it precipitates as ammonium or its double salt state and becomes a crystalline state, at this time, when cooling crystallization, the inorganic salt is matured as coarse crystal, so it can be easily removed by removing the inorganic salt by high-speed centrifugation. By adding 98% sulfuric acid, decomposition and humic substances are removed under high temperature and pressurization, it can be used as acid solution of neutralization of glutamic acid and crystallization process.

As described above, the present invention is characterized in that the concentration of the mother liquor is kept low so that the concentration of the mother liquor is kept low so that the inorganic salt is not precipitated in the glutamic acid recovery process of the glutamic acid separated mother liquor of the fermentation broth. Inorganic salts recovered with crude crystals can be easily separated and removed by high-speed centrifugal separators because they become crystalline together with glutamic acid dissolution when maintaining the concentration conditions of glutamic acid, acidity, cooling temperature, and inorganic salts. It is possible to improve the purity of glutamic acid, so that the recovery rate of glutamic acid and the content of the inorganic salt in the recovered mother liquor according to the present invention are shown in Table 1 below.

TABLE 1

The invention is illustrated in detail in the following examples.

Example 1

Add 50 g of HMP to 50 L of glutamic acid isolated mother liquor (PH3.3, glutamic acid 2.4g / dl, Ca ⁺⁺ 0.44g / dl, K ⁺ 0.86g / dl Mg ⁺⁺ 0.24g / dl, NH ₄ ⁺ 1.86g / dl) After stirring, the mixture was concentrated in vacuo to 28Be 'to obtain 16.4 L of concentrate.

The concentrated solution was cooled and crystallized and then separated by a high-speed centrifugal separator to obtain 2.5 Kg of glutamic acid crude crystal in which mineral salt crystals were mixed. To this glutamic acid crude crystal, 1230 ml of 8N sulfuric acid solution was added, and the glutamic acid solution adjusted to PH1.0, 30 Be 'was cooled and crystallized at 10 ° C for 4 hours, and separated by a high-speed centrifuge to obtain 640 g of inorganic salt and 3650 ml of a filtrate.

98% sulfuric acid was added to the filtrate, which was heated for 3 hours at a pressure of 3Kg / cm < 2 >, 120 ° C, cooled to room temperature, and filtered and removed 4230 ml of sulfated filtrate (15.8g / dl glutamic acid, Ca ⁺⁺ 0.02g /). dl, K ⁺ 0.43 g / dl, Mg ⁺⁺ 0.16 g / dl, NH ₄ ⁺ 0.41 g / dl).

Example 2

Glutamic acid separation mother liquor (PH3.4, glutamic acid 2.6g / dl, Ca ⁺⁺ 0.05g / dl, K ⁺ 1.24g / dl, Mg ⁺⁺ 0.32g / dl, NH ₄ ⁺ 2.64g / dl, 5KL HMP 0.7Kg The resulting solution was concentrated in vacuo to 27Be 'to obtain 1750 L of concentrate, which was cooled and crystallized to give 272 Kg of glutamic acid crude crystals containing a large amount of inorganic salts.

10 N sulfuric acid was added to the recovered crude glutamic acid to adjust the pH to 0.5 concentration 29 Be ', cooled crystallization at 10 ° C. for 8 hours, followed by centrifugation, and 98% sulfuric acid was added to the filtrate to remove 83 Kg of inorganic salt. / Cm, heated at 120 ° C. for 3 hours, cooled to room temperature and filtered to remove humics, 480 L (glutamic acid 15.0 g / dl, Ca ⁺⁺ 0.03 g / dl, K ⁺ 0.41 g / dl, Mg ^{+ +} 3.5 g / dl, NH ⁺ 1.56 g / dl).

Claims (2)

Recovering glutamic acid from glutamic acid separation mother liquor, which is characterized by separating and recovering inorganic salt and glutamic acid by recovering glutamic acid from molasses-containing glutamic acid fermentation mother liquor, adding sulfuric acid to the recovered glutamic acid crude crystal and cooling crystallization. Way. The method for recovering glutamic acid from the glutamic acid separation mother liquor according to claim 1, wherein the sulfuric acid is added to maintain the glutamic acid fermentation mother liquor at a concentration of 25-35Be ', PH 0.3-1.5.

Images