CN101579101A - Method for treating last monosodium glutamate mother liquor - Google Patents

Abstract

The invention discloses a method for treating a last monosodium glutamate mother liquor, which comprises the steps: removing sulfate radicals in the last monosodium glutamate mother liquor containing sodium pyroglutamate impurities through barium salt first, then using ionic membrane caustic soda to hydrolyze to ensure that sodium pyroglutamate is unlinked and transformed into sodium glutamate, precipitating a large amount of flocculent colloid at the same time, then removing precipitated colloid protein, salt precipitations and the like through two plate-and-frame filtrations, sending filtrate into an inorganic membrane for microfiltration separation to further remove impurities such as solid protein to obtain clear permeate liquid, sending the permeate liquid into a nanofilration membrane separation system to remove impurities such as soluble colloid, protein, residual sugar and pigment to obtain high-quality feed liquid, and re-sending the feed liquid into a monosodium glutamate production cycle chain to produce monosodium glutamate. The method removes impurities such as sulfate, metallic ions (such as calcium, magnesium, iron and the like), colloid, protein, residual sugar and pigment in the last monosodium glutamate mother liquor, improves the quality of the hydrolysis of the last monosodium glutamate mother liquor, replaces acid hydrolysis, reduces the consumption of a decoloring agent and the discharge amount of wastewater, and ensures that the production cost is greatly reduced.

Description

A kind of method of handling last monosodium glutamate mother liquor

Technical field

The invention belongs to the glutamate production technical field, relate to a kind of method of handling last monosodium glutamate mother liquor.

Background technology

Monosodium glutamate claims monosodium glutamate again, is the L-glutaminate sodium salt, has the crystallization water of a part, and the shape of crystal belongs to orthorhombic system, and crystal formation is the octahedron of prism-shaped, has strong delicate flavour, is the flavouring of consumption maximum in the world.Monosodium glutamate in the aqueous solution fully ionization become ionotropic glutamate and sodium ion, its aqueous solution with pH raise, at high temperature under the situation of long-time heating, sodium glutamate is destroyed, slough a part water in the molecule and change into sodium pyroglutamate, lose delicate flavour, sodium pyroglutamate does not have optical activity in addition, and it produces refining yield and end product quality are produced great adverse effect, but sodium pyroglutamate can open loop be transformed into sodium glutamate after acid, basic hydrolysis.Simultaneously sodium glutamate mother liquid is through circulating and recovering repeatedly, and its impurity content rolls up, and is used further to make monosodium glutamate, inevitablely influence quality aspect opaque, color and luster and light transmittance, the hygroscopicity.

Therefore, people study the method for handling last monosodium glutamate mother liquor one after another, and main method has following several:

(1) directly returns abstraction process, wait electrical method to reclaim glutamic acid continuously;

(2) directly return abstraction process, mix extraction glutamic acid in proportion with zymotic fluid;

(3) return abstraction process after the acid hydrolysis;

(4) abstraction process is returned in basic hydrolysis;

(5) the last mother liquor is pulled back to pH3.0, intermittently reclaim glutamic acid, with the operation decolouring, mother liquor returned abstraction process during glutamic acid was got back to.

At present, domestic Gourmet Powder Factory mainly adopts and returns abstraction process after the acid hydrolysis and add as sour stream and transfer the pH isoelectric point crystallization, and supernatant removes to adopt from the preface of handing over the PROCESS FOR TREATMENT last mother liquor of resin adsorption impurities removal then.Though the method can make sodium pyroglutamate be transformed into glutamic acid fully, and can remove impurity such as a part of colloid, albumen, but can not remove impurity such as metal ions such as sulfate radical, calcium magnesium, most of pigment molecular, colloid albumen, and strong acid corrosivity is big, device damage is serious, hydrolyzate through extract, after the preface of handing over, yield descends to some extent, simultaneously sour consumption, energy consumption, all will increase from handing over to consume.

For fear of above deficiency, the someone proposes the method with basic hydrolysis, and basic hydrolysis can change sodium pyroglutamate into sodium glutamate fully, has saved the soda acid consumption, but the pigment and the anion that produce in the alkaline hydrolysis process are had no idea to remove.

Therefore, in order to solve the deficiency that exists in the said method, our company tests through a large amount of, has invented a kind of method of efficient processing last monosodium glutamate mother liquor newly.

Summary of the invention

The objective of the invention is to solve problem such as the energy consumption height, the impurities removal that exist in the prior art last sodium glutamate mother liquid treatment technology be not thorough, a kind of method of efficient processing last monosodium glutamate mother liquor is provided.

The method method concrete operations step that the present invention handles last monosodium glutamate mother liquor is as follows:

1), last monosodium glutamate mother liquor enters hydrolyzer, adjust concentration to 18-28 ° of B é with running water or distilled water, detect sulfate radical content, sodium glutamate content in the feed liquid, open and stir, add an amount of brium carbonate inorganic salts according to sulfate radical content, general brium carbonate dosage wants big, fully reacts 60 minutes, have barium sulfate, precipitation of calcium carbonate to separate out, excessive brium carbonate still exists with the form of precipitation;

2), in step 1), add food grade 32% ionic membrane caustic soda hydrolysis, addition is the 20-40% of last monosodium glutamate mother liquor volume, stirring and evenly mixing, feed liquid is pumped into injector, be steam heated to 50 ℃-110 ℃, normal pressure is kept 90-180 minute, and is thorough until hydrolysis, hydrolyzate has part flocculent deposit and iron hydroxide, calcium hydroxide, magnesium hydrate precipitate to separate out, with cooling water temperature to 40 ℃-50 ℃;

3), step 2) in the cooling after hydrolyzate pump into plate-frame filtering, filter residue discards;

4), the filtrate in the step 3) is entered neutralizing tank, transfer pH to 7.0-7.5, have the part flocculent deposit to separate out with glutamic acid, plate-frame filtering again, filter residue discards;

5), the filtrate in the step 4) entered inorganic ceramic membrane carry out micro-filtration, pore size filter is 0.5～0.8um, operating pressure is the 0.3-1 MPa, temperature is 10-90 ℃, removes solid shape albumen in the feed liquid and colloid, inorganic salts precipitation etc., the hydrolyzate that obtains clarifying; In concentrate, add the dialysis water of 2-3 times of volume with residual sodium glutamate wash-out, merging through liquid or eluent goes step 1) to transfer concentration as low water, concentrate behind the wash-out is discharged to and makes fertilizer between cesspoolage truck, and the ceramic membrane micro-filtration is concentrated into the solid protein in the feed liquid and other insoluble matter etc. 5-15 times (weight ratio) of former content;

6), the hydrolyzate behind the micro-filtration is sent into the NF membrane piece-rate system again, NF membrane molecular interception molecular weight is 800, and operating temperature is 5-75 ℃, and pressure is the 1.5-4 MPa, removes impurity such as soluble protein, residual sugar, pigment, the feed liquid of further purifying; The dialysis water that adds 2-3 times of volume in concentrate is with residual sodium glutamate wash-out, and cycles of concentration about 5-15 doubly; Last high impurity concentrate is discharged to makes fertilizer between cesspoolage truck, nanofiltration processing back feed liquid enters the production chain mixes with other feed liquid, adopts conventional method for crystallising to make the monosodium glutamate finished product again.

The present invention's beneficial effect compared with prior art is: can make refining yield improve about 2.5%; Reduced the consumption of soda acid, reduced cost, benefit is obvious; The present invention can effectively remove Ca2+, Mg2+, Fe2+, SO42-plasma, and clearance can reach more than 90%; Remove impurity such as albumen, colloid, pigment with membrane process, can reduce the decolorizer consumption significantly; Because last monosodium glutamate mother liquor needn't return abstraction process, thereby has avoided ion-exchange process, thoroughly to remove resin and flowed out waste water and regenerative wastewater, wastewater flow rate reduces significantly; Because this method easy operating is convenient to control, so the feed liquid steady quality that obtains; This method corrosivity is little, and equipment maintenance is easy.

The specific embodiment

The present invention operates by following processing step:

1, last monosodium glutamate mother liquor 200L transfers concentration to 22 ° B é, detects index: sodium glutamate 25g/100ml, sodium pyroglutamate 15g/100ml, sulfate radical 1.6g/100ml, printing opacity 42%;

2, open stirring, add the 8kg brium carbonate, stirring reaction 60 minutes has barium sulfate, precipitation of calcium carbonate to separate out, and excessive brium carbonate still exists with the form of precipitation;

3, add 80L32% ionic membrane caustic soda stirring and evenly mixing then, pump into steam jet ejector steam and spray and to be heated to 100 ℃, normal pressure was kept hydrolysis 150 minutes, and hydrolysis is complete, and hydrolyzate has a large amount of flocculent deposits and iron hydroxide, calcium hydroxide, magnesium hydrate precipitate to separate out;

4, with cooling water temperature to 50 ℃, the hydrolyzate after the cooling is pumped into plate-frame filtering, filtrate is detected printing opacity 43%, sodium glutamate content 27.6g/100ml, SO ₄ ^2-0.08g/100ml hydrolysis is complete, filter residue discards;

5, filtrate enters neutralizing tank, transfers pH to 7.5 with glutamic acid, has a large amount of flocculent deposits to separate out;

6, the feed pump in the step 5 is gone into sheet frame and filter, filter residue discards;

7, filtrate enters inorganic ceramic membrane and carries out micro-filtration, and pore size filter average out to 0.5um, operating pressure are 0.8 MPa, and temperature is 65 ℃, and micro-filtration is removed inorganic salts precipitation that solid shape albumen in the feed liquid and colloid, sheet frame miss etc., the filtered fluid that obtains clarifying;

8, the about 66L of dialysis water that adds 3 times of concentrate volumes, with sodium glutamate wash-out residual in the concentrate, merge through liquid or eluent and go step 1 to transfer concentration, filtrate printing opacity 67% as low water, the feed liquid cycles of concentration is about 11 times, and the concentrate behind the wash-out is discharged to and makes fertilizer between cesspoolage truck;

9, the filtered fluid behind the micro-filtration is sent into the NF membrane piece-rate system again, NF membrane molecular interception molecular weight is 800, and operating temperature is 60 ℃, and 4 MPas are removed impurity such as soluble protein, residual sugar, pigment, the feed liquid of further purifying, feed liquid printing opacity 86%;

10, the dialysis water that adds 3 times of concentrate volumes with the sodium glutamate wash-out in the concentrate after, cycles of concentration is discharged to and makes fertilizer between cesspoolage truck about 10.5 times;

11, the hydrolyzate after nanofiltration enters and produces chain and mix with other feed liquid, adopts conventional method for crystallising to make the monosodium glutamate finished product again.

Claims (1)

1, a kind of method of handling last monosodium glutamate mother liquor is characterized in that by following processing step operation:

1) last monosodium glutamate mother liquor is sent in the hydrolyzer, added brium carbonate and remove sulfate radical, the amount of the barium salt of adding will be according to the SO in every batch of last mother liquor ₄ ^2-Content and deciding;

2) sulfate radical post precipitation adds 32% ionic membrane caustic soda hydrolysis, adds the 20%-40% that alkali number is the last monosodium glutamate mother liquor volume, and hydrolysis temperature is 50 ℃-110 ℃, and normal pressure was kept 90-180 minute, and sodium pyroglutamate is unlinked, and generates Ca when finishing hydrolysis ²⁺, Mg ²⁺, Fe ²⁺Deng the precipitation of hydroxide of metal ion, and there are a large amount of cotton-shaped colloids to separate out;

3) hydrolyzate is removed precipitations such as the colloid albumen of separating out, salt by plate-frame filtering;

4) filtrate is transferred pH to 7.0-7.5 with glutamic acid, makes it to separate out once more Partial Protein, colloid, passes through plate-frame filtering once more;

5) filtrate is sent into inorganic ceramic membrane microfiltration piece-rate system, pore size filter is 0.5-0.8um, film lock out operation pressure is the 0.3-1 MPa, operating temperature 10-90 ℃, remove in the hydrolyzate solid shape albumen and colloid, inorganic salts precipitation through micro-filtration, obtain clarifying hydrolyzate, the dialysis water that adds 2-3 times of volume in concentrate is with residual sodium glutamate wash-out, and cycles of concentration is 5-15 a times of weight ratio;

6) will send into the NF membrane piece-rate system through the hydrolyzate of micro-filtration, the NF membrane molecular weight that dams is 800, operating temperature is 5-75 ℃, pressure is the 1.5-4 MPa, remove solvable colloid, albumen, residual sugar pigment impurity, the dialysis water that adds 2-3 times of volume in concentrate is with residual sodium glutamate wash-out, and cycles of concentration is 5-15 a times of weight ratio;

7) NF membrane see through hydrolyzate enter the glutamate production chain in and operation, participate in the feed liquid circulation and make the monosodium glutamate finished product, the last high impurity concentrate of nanofiltration is used to make fertilizer.