CN113087635A

CN113087635A - Comprehensive utilization method of glycine crystallization mother liquor by hydantoin method and implementation device thereof

Info

Publication number: CN113087635A
Application number: CN202110376916.7A
Authority: CN
Inventors: 李显扬; 应国海; 耿海涛
Original assignee: Bozun Investment Group Co Ltd
Current assignee: Bozun Investment Group Co Ltd
Priority date: 2021-04-08
Filing date: 2021-04-08
Publication date: 2021-07-09

Abstract

The invention relates to a comprehensive utilization method of glycine crystallization mother liquor by a hydantoin method and an implementation device thereof. The method comprises the steps of contacting a hydantoin-method glycine crystallization mother liquor with a zirconium raw material to perform hydrolysis reaction, then mixing a glycine aqueous solution with an inorganic metal salt to perform chelation reaction, and after performing pH adjustment, effectively converting the salt of the glycine metal chelate into the glycine metal chelate and obtaining byproducts such as ammonium salt or calcium sulfate. Compared with the traditional process using commercial grade glycine, the method for preparing the glycine metal chelate by utilizing the hydantoin method glycine mother liquor has the advantages of low production cost, comprehensive utilization of wastes, simple equipment operation, easy maintenance, high product yield, high stability, high recovery rate of glycine, no generation of three wastes, environmental protection, cleanness and the like.

Description

Comprehensive utilization method of glycine crystallization mother liquor by hydantoin method and implementation device thereof

Technical Field

The invention belongs to the field of organic chelate preparation, and particularly relates to a method for preparing glycine metal chelate by comprehensively utilizing a hydantoin method glycine mother liquor and a device for implementing the method.

Background

The trace elements are very important nutritional additives, and the trace element additives commonly used in feed and premix at present mainly comprise inorganic salts such as sulfate, chloride, oxide and the like, and have a plurality of defects, such as: in animal nutrition, due to the complex chemical reaction in the digestion process, the feed is easily affected by phosphate (such as calcium hydrophosphate, calcium dihydrogen phosphate), phytic acid and other components in the feed, so that insoluble precipitates are formed, the biological potency is reduced, and the absorption and utilization are affected; in feed processing, inorganic salt generally contains crystal water and is easy to absorb moisture and agglomerate; the inorganic salt has strong destructive effect on vitamins, grease and the like; some feed factories adopt high-manganese and high-zinc feed, the yield is low, and the environment is seriously polluted.

The test result of the glycine chelate metal compound for broiler shows that the weight gain speed of the test group is increased by 5.28% compared with the control group, the feed conversion rate is increased by 2.59%, 1500 glycine chelate metal compounds are fed in one batch, and 2100 yuan can be increased for 5 batches of breeders in the year. The results of experiments on the laying hens in the Decka by Sundecheng et al (1995) show that the total egg weight and the laying rate of the experimental group are respectively improved by 21.02% and 12.80% compared with those of the control group, and the feed-egg ratio and the soft-breaking rate are respectively reduced by 20.74% and 31.79%; the metabolism test also shows that the absorption utilization rates of the iron, copper, manganese and zinc elements in the test group are respectively improved by 71.65%, 93.07%, 188.08% and 107.42% compared with the control group.

The ferrous glycine chelate can obviously improve the reproductive performance of sows, improve the body conditions of the sows, reduce the elimination rate of the sows during the birth, prevent the anemia and diarrhea of piglets and reduce the death rate of the piglets. The feed added with glycine chelated iron (500ppm) is fed 21-28 days before the birth of the sow, so that the postpartum piglets do not need to be supplemented with iron, the death rate of the piglets is obviously reduced, the weaning weight is larger, and the breeding rate of the weaning piglets can reach 94%. The experimental study of the compound amino acid chelate and the ecological preparation feed additive on the fattening pigs shows that the daily gain ratio is improved by 17.82 percent compared with the control, the feed conversion ratio is reduced by 14.43 percent, and the economic benefit is improved by 70.38 percent.

The glycine chelate metal compound has obvious effects on promoting the growth of fish, improving the feed conversion rate and the survival rate of fish, and is an ideal nutritional feed additive suitable for the nutritional requirements of fish. The feeding test of Zhaoyuan phoenix et al (1994) on carp shows that the weight gain of the carp added with glycine chelate metal compound is increased by 37.2-68.1% compared with the control group, and the bait coefficient is reduced to 1.4-1.7 from 2.4 of the control group. Liaijie et al (1994) add glycine chelate metal compound, Cu 2Mg, Zn 30Mg, Mn 12Mg, Fe 150Mg, Co 2Mg and Mg 400Mg in each kilogram of feed, can accelerate the growth of tilapia, and improve the weight gain rate by 17.84% -25.84% compared with inorganic trace elements; for crucian carp, the digestibility of trace elements can be improved, the Cu and Co are 41-58%, the Fe and Zn are 14-16%, and the Mn is 5-7%.

Therefore, the glycine chelate metal compound has stable chemical performance, high biological value, no toxicity, no stimulation, good palatability, no incompatibility with vitamins, antibiotics and the like, has certain functions of sterilizing and improving immunologic function, has curative effect on enteritis, dysentery and anemia, and has stable chemical properties. As a feed additive, the compound feed additive has the double functions of supplementing trace elements and amino acids, can reduce the feed consumption and improve the feed conversion utilization rate, and has obvious economic benefit.

The direct hydantoin method is an important production method of glycine, the method takes hydroxyacetonitrile and ammonium bicarbonate as raw materials, the hydroxyacetonitrile, ammonia, carbon dioxide and water are subjected to high-temperature and high-pressure reaction according to the feeding molar ratio of 1:6:3:46, ammonia and carbon dioxide are discharged to generate glycine aqueous solution, and a glycine product and a glycine mother solution are obtained through decoloring, concentrating, cooling and crystallizing. However, there is also a problem that some organic impurities such as hydantoin, hydantoin acid amide, glycine dipeptide, glycine tripeptide, 2, 5-diketopiperazine, glycinamide and unreacted hydantoin are generated during the production of glycine, and these compounds are shown below. The reason for generating the impurities is that the hydroxyacetonitrile firstly reacts with ammonia to generate aminoacetonitrile, then the aminoacetonitrile forms a ring under the action of carbon dioxide, and the hydantoin ring is unstable and decomposed into glycine, carbon dioxide and ammonia after a small amount of aminolysis and high temperature and high pressure. However, in this process, the hydantoin ring is incompletely decomposed, and impurities such as hydantoin acid, hydantoin acid amide, glycine dipeptide, glycine tripeptide, 2, 5-diketopiperazine, and glycine amide are generated, which affects the recycling of the glycine mother liquor. Furthermore, in order to obtain feed-grade and food-grade glycine, it is often necessary to recrystallize a crude glycine product, and after recrystallization, although a high-quality glycine product can be obtained, the recrystallization mother liquor cannot be recycled for many times, and the main reason is that impurities such as hydantoin, hydantoin amide, glycine dipeptide, glycine tripeptide, 2, 5-diketopiperazine, glycinamide and the like are also carried in the crude glycine product, and the impurities which are not converted into glycine remain in the recrystallization mother liquor during recrystallization, and are accumulated to the limit along with recycling of the recrystallization mother liquor, so that the circulation of the mother liquor is affected, and the recrystallization mother liquor needs to be periodically extracted for treatment so as not to affect the quality of the glycine product. In industrial processes, in order to prevent the accumulation of these impurities, a part of glycine crystallization mother liquor is generally extracted and incinerated, and the amount of the mother liquor extracted and incinerated is generally about 10% of the mass of the mother liquor, which inevitably results in a great amount of glycine loss. Although impurities such as hydantoin acid, hydantoin acid amide, glycine dipeptide, glycine tripeptide, 2, 5-diketopiperazine, glycine amide exist in the glycine mother liquor, the impurities are converted into glycine under conditional conditions, and the conversion is sometimes complete, such as under high temperature conditions or alkaline conditions, but is incomplete under high temperature conditions, and even a reversible reaction is likely to occur, particularly under conditions of non-selected materials, the glycine also has the following reaction:

although the glycine can be completely hydrolyzed and converted into the glycine under the alkaline condition, the part of mother liquor treated by the alkali liquor can not be recycled to the original reaction system, and is usually treated by acidification and crystallization, a large amount of inorganic sodium salt and saline wastewater which is difficult to treat are by-produced, and the production cost of the glycine is increased. The disposal by incineration is therefore directly effective, at least in the present case analyzed. However, the method wastes resources, pollutes the environment and causes the increase of the production cost of the glycine.

Chinese patent application No. 202110250881.2, which is a prior application of the present inventors, relates to a method for preparing a salt of glycine metal chelate (e.g., having a structure shown in the following formula (I)) using a hydantoin-process glycine mother liquor, but does not relate to how to prepare the glycine metal chelate itself (e.g., having a structure shown in the following formula (II)). It is an object of the present application to utilize the hydantoin process glycine mother liquor to prepare glycine metal chelates, an improvement over the earlier applications described above.

Therefore, there is a need in the art to develop a method for producing valuable products (such as glycine metal chelate) by comprehensively utilizing the glycine mother liquor obtained by the direct hydantoin process, which not only prevents impurities from accumulating in the mother liquor to affect the recycling of the mother liquor, but also fully recovers impurities such as glycine and glycine derivatives thereof in the mother liquor, avoids direct incineration treatment, and achieves the purpose of fully utilizing the waste.

Disclosure of Invention

In view of the above technical problems, the present inventors have found that impurities (such as hydantoin, hydantoin acid, hydantoin amide, glycine dipeptide, diketopiperazine, glycine tripeptide) in a glycine mother liquor can be efficiently converted into glycine by utilizing the effect of zirconium on the hydrolysis reaction of these impurities. Meanwhile, the inventor also finds that for zinc glycine chelate and the like, the glycine metal chelate can be directly separated out as a solid precipitate by adjusting the pH of an aqueous solution of glycine complex metal salt with alkali (such as ammonia water) to 5-7, and byproducts such as ammonium salt and the like are also by-produced; or for ferrous glycine chelate, pH adjustment (to 5.5-6.5) is carried out on the glycine complex metal salt aqueous solution by alkali (such as calcium oxide or calcium hydroxide), calcium sulfate serving as a byproduct can be directly separated out as a solid precipitate, and filtrate is concentrated and dried to obtain a glycine metal chelate (namely ferrous glycine chelate); the purity of the glycine metal chelate can reach more than 98%, and the recovery utilization rate of glycine can reach more than 95%. In view of the above, the present invention provides a method for preparing a glycine metal chelate containing trace elements by using a glycine crystallization mother liquor and an apparatus for implementing the method.

In one aspect, the invention provides a comprehensive utilization method of a glycine crystallization mother liquor by a hydantoin method, wherein the method comprises the following steps:

(1) contacting a hydantoin method glycine crystallization mother liquor with a zirconium raw material, and then heating and preserving heat to perform hydrolysis reaction to obtain a glycine aqueous solution, wherein the zirconium raw material comprises zirconium, zirconium-containing alloy, zirconium salt, zirconium oxide or any mixture thereof;

(2) removing ammonia and carbon dioxide from the glycine aqueous solution obtained in the step (1), and then performing decolorization and reduced pressure concentration treatment to obtain a concentrated glycine aqueous solution;

(3) mixing the concentrated glycine aqueous solution obtained in the step (2) with inorganic metal salt, adding a pH regulator into a reaction system to regulate the pH to 5-7 for chelation reaction, and separating, washing and drying solid precipitates obtained after the chelation reaction to obtain a glycine metal chelate; or separating, concentrating and drying the supernatant after the chelation reaction to obtain the glycine metal chelate.

In another aspect, the present invention provides a glycine metal chelate prepared by the above method.

In another aspect, the present invention provides a feed additive, wherein the feed additive comprises a glycine metal chelate prepared by the above method.

In yet another aspect, the present invention provides an apparatus for performing the above method, wherein the apparatus comprises a hydrolysis reactor, a stripping column, a decoloring tank, a concentrating tank, a chelating reactor, a separation system, and a drying system, which are connected in series in fluid communication.

Advantageous effects

The feed-grade glycine metal chelate is prepared by utilizing the hydantoin method glycine mother liquor, and compared with the traditional method of using commercial-grade glycine, the feed-grade glycine metal chelate has the advantages of low production cost and comprehensive utilization of wastes; the method disclosed by the invention has the advantages of cleanness, environmental protection, simplicity in operation, high yield, high product stability, high recovery rate of glycine in the mother liquor, no generation of three wastes, environmental protection, cleanness and the like. In addition, the device has the advantages of simple operation, easy maintenance of equipment and the like. The glycine metal chelate obtained by the method has high yield, high recovery rate of glycine and high product stability, and can produce ammonium salt or calcium sulfate as a byproduct, thereby being a good method for comprehensively utilizing the glycine crystallization mother liquor by the hydantoin method.

Drawings

FIG. 1 is a schematic diagram of an exemplary apparatus for producing glycine metal chelate according to the present invention.

Wherein each symbol represents: the system comprises a hydrolysis reactor 1, a stripping tower 2, a decoloring kettle 3, a concentration kettle 4, a chelation reaction kettle 5, a separation system 6, a bipyramid drying system 7 and a spray drying system 8.

FIG. 2 is an infrared spectrum of zinc glycine chelate prepared by the present invention;

FIG. 3 is an infrared spectrum of ferrous glycine chelate prepared by the present invention.

Detailed Description

The invention will be described below with reference to exemplary embodiments, but the scope of protection of the invention is not limited thereto.

In the present invention, unless otherwise indicated, the terms "glycine crystallization mother liquor", "hydantoin process glycine mother liquor", "mother liquor" and "glycine mother liquor" are used interchangeably to refer to the raffinate after synthesis and isolation of a glycine product using the direct hydantoin process and/or the glycine recrystallization mother liquor.

In the present invention, unless otherwise specified, the terms "chelated metal compound", "complexed metal compound", "metal complex", "metal chelate" and "glycine metal chelate" are used interchangeably to refer to a complex formed by coordination of a metal ion with glycine. For example, the glycine metal chelate has the structure shown in the following formula:

in the present invention, the term "atmospheric pressure" means 1 standard atmospheric pressure unless otherwise specified.

The inventor finds that zirconium can promote impurities (such as hydantoin, hydantoin acid, hydantoin amide, glycinamide, glycine dipeptide, diketopiperazine and glycine tripeptide) in the hydantoin method glycine mother liquor to be completely converted into glycine products through hydrolysis reaction. It is known in the art that glycine undergoes a dynamic equilibrium reaction at elevated temperatures, where partial conversion of glycine to glycine dimers (i.e., glycine dipeptides) and trimers (i.e., glycine tripeptides) and the like, is favored by higher temperatures. However, the present inventors have found that this conversion can be prevented in the presence of zirconium or zirconium ions, and even that glycine dimers, trimers, etc. obtained by the conversion can be promoted to be hydrolyzed into glycine in the presence of zirconium or zirconium ions.

As an example, the present inventors have also found that if adding zirconium material to the material of the hydrolysis reactor of glycine crystallization mother liquor, it is not only advantageous to enhance the resistance of the reactor to corrosion of the reactor by carbon dioxide and ammonia under high temperature and pressure conditions, but also to directly affect the effect of the hydrolysis reaction (making the equilibrium of the hydrolysis reaction proceed to the left, facilitating the formation of glycine product), so that impurities in the mother liquor, such as hydantoin, hydantoin acid, hydantoin amide, glycine dipeptide, diketopiperazine, glycine tripeptide, etc., can be completely and effectively converted into glycine product.

In one embodiment, the invention relates to a comprehensive utilization method of glycine crystallization mother liquor by a hydantoin method, wherein the method comprises the following steps:

In some preferred embodiments, in step (1), the total nitrogen content of the glycine crystallization mother liquor is 1.20 wt% to 7.5 wt%, preferably 3.0 wt% to 5.5 wt%. In a further preferred embodiment, the glycine crystallization mother liquor comprises the following components in percentage by mass: 5 to 30 parts of glycine, 0.5 to 4.0 parts of glycine dipeptide, 0.1 to 1.0 part of glycine tripeptide, 0.1 to 2.0 parts of hydantoin, 0.2 to 1.0 part of diketopiperazine, 0.1 to 1.0 part of glycinamide, 0.05 to 0.3 part of hydantoin, 0.05 to 0.2 part of hydantoin amide, 50ppm or less of ammonia, and the balance of water.

In a further preferred embodiment, the method further comprises producing the hydantoin process glycine mother liquor by: feeding hydroxyl acetonitrile, ammonia, carbon dioxide and water according to a molar feeding ratio of 1:6:3 (44-46), wherein the reaction temperature is 140-160 ℃, and the reaction time is 2-3 hours; after the reaction is finished, removing carbon dioxide and ammonia which do not participate in the reaction through steam stripping to obtain a dilute glycine solution (preferably, the mass percentage of glycine in the dilute glycine solution is 7.0-15 wt%); decoloring, concentrating, cooling and crystallizing to obtain a crude glycine (the mass percentage of the glycine is 94.0-98.0 wt%), separating the crude glycine, and taking the obtained crystallization mother liquor as the hydantoin-method glycine crystallization mother liquor.

In a further preferred embodiment, the process further comprises producing the hydantoin process glycine crystallization mother liquor by: adding water into the crude glycine product for recrystallization, separating the recrystallized glycine to obtain a recrystallization mother liquor, and taking the single recrystallization mother liquor or the mixture of the recrystallization mother liquor and the crystallization mother liquor as the hydantoin-process glycine crystallization mother liquor.

In some preferred embodiments, in step (1), the zirconium feedstock may be in the form of reactor linings, chunks, powders, and the like.

In some preferred embodiments, in step (1), the zirconium-containing alloy is an alloy having a zirconium content of 5 wt% to 30 wt%. Preferably, the zirconium-containing alloy may be, for example, a zirconium iron alloy, a zirconium cobalt alloy, a zirconium copper alloy, a zirconium tin alloy, a zirconium aluminum alloy, a zirconium niobium alloy, or any mixture thereof, and the like, but is not limited thereto.

In some preferred embodiments, in step (1), the zirconium salt is an inorganic zirconium salt; preferably, the inorganic zirconium salt includes, but is not limited to, zirconium sulfate, zirconium chloride, zirconium carbonate (e.g., zirconium basic carbonate), zirconium nitrate, zirconium phosphate, zirconium acetate, or any mixture thereof.

In some preferred embodiments, in the step (1), the amount of the zirconium raw material added is 20 to 500ppm of the mass of the hydantoin-process glycine crystallization mother liquor, based on the mass of the zirconium element.

In some preferred embodiments, in the step (1), the hydrolysis reaction is performed by heating to 150-170 ℃ and maintaining the temperature for 30-90 min with stirring at a speed of 60-200 r/min. In some embodiments, in step (1), the pressure of the hydrolysis reaction is 1.2 to 3.0 MPa.

In some embodiments, in step (2), the aqueous glycine solution of step (1) is subjected to a stripping treatment to remove ammonia and carbon dioxide. In the present invention, stripping is carried out using conventional operating conditions known in the art.

In some embodiments, in step (2), the decolorizing treatment is performed with activated carbon or a nanofiltration membrane, preferably activated carbon. In a further preferred embodiment, the amount of the activated carbon is 0.2 wt% to 1.0 wt% of the total mass of glycine in the aqueous glycine solution. In a further preferred embodiment, the temperature of the decolorization treatment is 40 to 70 ℃ and the time is 20 to 40 min.

The concentration under reduced pressure in the above-mentioned step (2) of the present invention is a conventional operation in the art. In the present invention, a small amount of ammonia and excess water produced can be removed by the concentration-compression treatment.

In some embodiments, in step (2), the mass percentage of glycine in the concentrated glycine aqueous solution is 15.0 wt% to 32.0 wt%.

In some embodiments, in step (3), the charged molar ratio of glycine to inorganic metal salt in the concentrated aqueous glycine solution is 2: 1.

In some preferred embodiments, in step (3), the inorganic metal salt is an anhydrous compound or hydrate of zinc sulfate, zinc chloride, zinc acetate, copper sulfate, copper chloride, copper acetate, manganese sulfate, manganese chloride, manganese acetate, nickel sulfate, nickel chloride, cobalt sulfate, cobalt chloride, cobalt acetate, ferrous sulfate, or any mixture thereof. Preferably, the inorganic metal salt is in the form of an aqueous solution thereof, particularly preferably a saturated aqueous solution.

In some preferred embodiments, in step (3), the pH adjusting agent is a base, preferably an inorganic base. Preferably, the alkali is one or more of sodium carbonate, potassium carbonate, lithium carbonate, sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium oxide, calcium hydroxide, ammonia gas, ammonia water and the like, preferably ammonia, calcium oxide and calcium hydroxide, and the pH value of the chelation reaction is controlled to be 5-7.

In some preferred embodiments, in the step (3), the chelating reaction temperature is 40 to 70 ℃, preferably 50 to 65 ℃, and the time is 90 to 120min, preferably 90 to 100 min.

In some preferred embodiments, in step (3), the solid precipitate after the chelation reaction is separated from the supernatant by suction filtration for 50 to 100min (e.g., 60 to 80 min). In other preferred embodiments, in step (3), the solid precipitate and supernatant after the chelation reaction are separated by centrifugation.

In some preferred embodiments, in step (3), the glycine metal chelate compound contains any one or more of zinc, iron, copper, manganese, nickel and cobalt. That is, the glycine metal chelate is any one or more of zinc glycine chelate, ferrous glycine chelate, copper glycine chelate, manganese glycine chelate, nickel glycine chelate and cobalt glycine chelate.

In some preferred embodiments, in step (3), the chemical structure of the glycine metal chelate is as follows:

in some preferred embodiments, in step (3), when the glycine metal chelate is one or more of zinc glycine chelate, copper glycine chelate, manganese glycine chelate, nickel glycine chelate and cobalt glycine chelate, the solid precipitate after the chelation reaction is separated, washed (preferably with water) and dried to obtain the glycine metal chelate. Preferably, the filtrate obtained by separation is concentrated and crystallized to obtain one or more of ammonium sulfate, ammonium chloride and ammonium acetate as byproducts.

In some preferred embodiments, in step (3), when the glycine metal chelate is ferrous glycine chelate, the supernatant after the chelation reaction is separated, concentrated and dried to obtain glycine metal chelate. Preferably, the solid precipitate obtained by separation (e.g. calcium sulphate) is used as a by-product.

In some preferred embodiments, in step (3), when the glycine metal chelate is ferrous glycine chelate, the concentrated aqueous glycine solution of step (2) is mixed with ferrous sulfate and a complex oxidant to prepare ferrous glycine chelate. Preferably, the feeding molar ratio of glycine to ferrous sulfate in the concentrated glycine aqueous solution is 2:1, the composite oxidant is citric acid and reduced iron powder, and the feeding amount of the composite oxidant is 5 wt% -10 wt% of the mass of glycine. Preferably, the pH adjuster is an alkali, preferably one or both of calcium oxide and calcium hydroxide.

In some preferred embodiments, the method comprises the steps of:

(i) enabling a hydantoin-method glycine crystallization mother liquor to be in contact with a zirconium raw material in a reactor lining form, heating to 150-170 ℃ under stirring at a speed of 60-200 r/min, preserving heat for 30-90 min, and carrying out hydrolysis reaction, wherein the pressure of the hydrolysis reaction is 1.2-3.0 MPa, and after the reaction, releasing pressure to normal pressure to obtain a glycine aqueous solution;

(ii) carrying out steam stripping treatment on the obtained glycine aqueous solution to remove ammonia and carbon dioxide to obtain feed liquid (I); adding active carbon into the feed liquid (I) for decolorization, wherein the adding amount of the active carbon is 0.2-1.0 wt% of the total mass of the glycine, the temperature of the decolorization is 40-70 ℃, and the time of the decolorization is 20-40 min, removing the active carbon after the decolorization is finished, and performing reduced pressure concentration treatment on the decolorized feed liquid to obtain a concentrated glycine aqueous solution;

(iii) when the glycine metal chelate is any one or more of zinc glycine chelate, copper glycine chelate, manganese glycine chelate, nickel glycine chelate and cobalt glycine chelate, mixing the concentrated glycine aqueous solution obtained in the step (ii) with an inorganic metal salt aqueous solution, then adding ammonia to adjust the pH of the reaction system to 5-7, reacting at 50-65 ℃ for 90-100 min, separating the precipitate, washing with water and drying to obtain the glycine metal chelate;

or when the glycine metal chelate is glycine chelated ferrous iron, mixing the concentrated glycine aqueous solution obtained in the step (ii) with a ferrous sulfate aqueous solution and a composite oxidant (preferably citric acid and reduced iron powder), then adding calcium oxide or calcium hydroxide to adjust the pH value of the reaction system to 5.5-6.5, wherein the feeding amount of the composite oxidant is 5-10 wt% of the mass of glycine, the reaction temperature is 50-65 ℃, the reaction time is 90-100 min, separating calcium sulfate, and directly performing spray drying on the filtrate to obtain the glycine chelated ferrous iron.

In some embodiments, the process is one or more of a batch, semi-continuous, or continuous process, preferably a semi-continuous or continuous process.

The method comprehensively utilizes the glycine mother liquor synthesized by the direct hydantoin method and the glycine recrystallization mother liquor thereof, and can realize the comprehensive utilization of wastes. The purity of the glycine metal chelate obtained by the method reaches more than 98%, and the recovery utilization rate of glycine reaches more than 95%.

In some embodiments, the present invention relates to a glycine metal chelate prepared by the above-described method.

In one embodiment, the present invention relates to a feed additive, wherein the feed additive comprises a glycine metal chelate prepared by the above method.

In some embodiments, the glycine metal chelate contains any one or more of zinc, iron, copper, manganese, nickel, and cobalt.

In a further preferred embodiment, the chemical structure of the glycine metal chelate is as follows:

in some embodiments, the feed additive further comprises a feedinglogically acceptable adjuvant. For the auxiliary materials acceptable in the feed science, those skilled in the art can easily select suitable materials according to the relevant records in the prior art (e.g., < feed additive item catalog (2013) >, etc.).

In one embodiment, the present invention relates to an apparatus for carrying out the above method, wherein the apparatus comprises a hydrolysis reactor, a stripping column, a decolorization tank, a concentration tank, a chelation tank, a separation system, and a drying system, connected in series in fluid communication. Preferably, the hydrolysis reactor and the concentration kettle are respectively provided with a pressure device. Preferably, the hydrolysis reactor, the concentration kettle, the chelation reaction kettle and the drying system are respectively provided with a temperature adjusting auxiliary device. Preferably, the drying system is a double cone dryer or a spray drying system. Preferably, the separation system comprises one or more of a centrifuge, a filter flask, a buchner funnel, a vacuum circulating pump.

An exemplary embodiment of the present invention is described below with reference to fig. 1:

the device for producing the glycine metal chelate by using the glycine crystallization mother liquor comprises a hydrolysis reactor (1), a stripping tower (2), a decoloring kettle (3), a concentration kettle (4), a chelation reaction kettle (5), a separation system (6) and a double-cone dryer (7), which are communicated by fluid; the glycine chelated ferrous iron production device comprises a hydrolysis reactor (1), a stripping tower (2), a decoloring kettle (3), a concentration kettle (4), a chelated reaction kettle (5), a separation system (6) and a spray drying system (8); wherein, the outlet of the hydrolysis reactor (1) is connected with the inlet of the stripping tower (2), the inlet of the decoloring kettle (3) is connected with the outlet of the stripping tower (2), the inlet of the concentration kettle (4) is connected with the outlet of the decoloring kettle (3), the inlet of the chelating kettle (5) is connected with the outlet of the concentration kettle (4), the inlet of the separation system (6) is connected with the outlet of the chelating kettle (5), the inlet of the double-cone dryer (7) is connected with the outlet of the separation system (6), or the inlet of the spray drying system (8) is connected with the outlet of the separation system (6); hydrolysis reactor (1), concentrated cauldron (4) all be equipped with pressure and temperature auxiliary device, hydrolysis reactor (1), concentrated cauldron (4), chelate reation kettle (5), spray drying system (8) all be equipped with temperature regulation auxiliary device.

Introducing the hydantoin-method glycine crystallization mother liquor into a hydrolysis reactor (1) lined with a zirconium material, heating while stirring, and keeping the temperature to perform hydrolysis reaction. After the reaction, cooling and depressurizing to normal pressure to obtain the glycine aqueous solution. Stripping the glycine aqueous solution through a stripping tower (2) to remove ammonia and carbon dioxide to obtain a feed liquid I; and (3) feeding the obtained feed liquid I into a decoloring kettle (3), adding activated carbon for decoloring, removing the activated carbon after decoloring, and transferring the decolored feed liquid into a concentration kettle (4) for carrying out reduced pressure concentration treatment to obtain feed liquid II. And transferring the obtained feed liquid II into a chelation reaction kettle (5), adding inorganic metal salt, adjusting the pH value of a reaction system to 5-7, heating under stirring to perform chelation reaction, and introducing the obtained mixture into a separation system (6) to obtain solid precipitate and filtrate. When the glycine metal chelate is zinc glycine chelate, copper glycine chelate, manganese glycine chelate, nickel glycine chelate and cobalt glycine chelate, the solid precipitate obtained by separation in the separation system (6) is the corresponding glycine metal chelate, and the solid precipitate directly enters a double-cone dryer (7) to obtain the dried glycine metal chelate. When the glycine metal chelate is glycine chelated ferrous iron, the solid precipitate obtained by separation in the separation system (6) is calcium sulfate, and the filtrate obtained by separation in the separation system (6) is concentrated and enters a spray drying system (8) for spray drying treatment to obtain glycine chelated ferrous iron.

Examples

Hereinafter, preferred embodiments of the present invention will be described in detail. The experimental procedures, which are not specifically mentioned in the preferred examples, are generally conventional and are illustrated in the examples to better illustrate the present invention, but are not intended to limit the scope of the present inventionAnd (4) carrying out the following steps. Therefore, those skilled in the art can make insubstantial modifications and adaptations to the embodiments of the present invention based on the above disclosure, and still fall within the scope of the present invention. In the following examples, the total nitrogen content in the glycine mother liquor was measured by Kjeldahl method, and ion chromatography (Switzerland cation chromatography, Mrtrossrp C4250 column, analysis conditions were that eluent was 1.7mol/L HNO₃Aqueous solution, flow rate of 1.0ml/min, sample injection volume of 20 microliter) to analyze the content of impurities such as glycine and glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like in the glycine crystallization mother liquor.

Unless otherwise indicated, each of the reagents, materials and devices employed in the following examples and comparative examples are commercially available reagents, materials and devices known in the art. Unless otherwise indicated, the various operations hereinafter are conventional operations known in the art, as may be found, for example, in the following descriptions: wangzkui et al, "principles of chemical industry (fifth edition), chemical industry publishers, 1 month in 2018; yellow portrait, et al, "general theory of fine chemical industry (second edition), chemical industry publishers, 3 months 2015; chang et al, Fine chemical engineering principles and technology, Sichuan scientific and technical Press, 10 months in 2005.

The glycine metal chelate prepared in the embodiment of the invention has a structure shown as the following formula:

example 1

700 g of glycine mother liquor having a total nitrogen content of 3.36 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant zirconium-lined reactor having a feed and a stirrer: glycine 15.0 wt%, glycine dipeptide 1.5 wt%, hydantoin 0.3 wt%, diketopiperazine 0.2 wt%, glycine tripeptide 0.2 wt%, glycinamide 0.4 wt%, hydantoin acid 0.2 wt%, hydantoin acid amide 0.2 wt%, ammonia 20 ppm. Immediately heating to 165 ℃ under the stirring condition at the speed of 60r/min, preserving the temperature for 1.5 hours to perform hydrolysis reaction (the pressure is 3.0MPa), then cooling to about 100 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 688 g of glycine aqueous solution, wherein the glycine aqueous solution is yellow brown, the mass percentage of glycine in the reaction material is 18.31 wt% by ion chromatography, impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like are not detected, and the impurities are completely converted into glycine.

And (3) carrying out steam stripping treatment on the glycine aqueous solution obtained above to remove ammonia and carbon dioxide. Then adding 1 g of activated carbon, stirring for 30min at 50 ℃, and then carrying out suction filtration to obtain a decolorized glycine aqueous solution, wherein the color of the aqueous solution is colorless transparent liquid. The decolorized solution was concentrated in a concentration kettle under reduced pressure until the mass percentage of glycine was 32 wt%, to give a concentrated aqueous glycine solution having a weight of 393.67 g (molar amount of glycine: 1.68 mol).

Adding 410.96 g (0.84mol) of 33 wt% zinc sulfate aqueous solution into the obtained concentrated glycine aqueous solution introduced into a chelation reaction kettle, heating to 55 ℃ under a stirring state to obtain a uniform reaction mixed solution, then dropwise adding 25 wt% ammonia water to adjust the pH of the reaction system to 5.5-6.0, stirring for 80 minutes under a heat preservation condition, carrying out suction filtration on a separated white precipitate, washing a small amount of water, pouring the solid into a porcelain plate, putting into a forced air drying oven to dry (105 ℃) to constant weight to obtain 174.80 g of white powdery glycine chelated zinc product, wherein the purity is 98.5%, the yield is 96%, the recovery rate of glycine is not less than 95.0%, and concentrating and crystallizing the filtrate to obtain an ammonium sulfate byproduct. The IR spectrum of the zinc glycine chelate product prepared in this example is shown in FIG. 2.

Example 2

700 g of glycine mother liquor having a total nitrogen content of 3.36 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant zirconium-lined reactor having a feed and a stirrer: glycine 15.0 wt%, glycine dipeptide 1.8 wt%, hydantoin 0.1 wt%, diketopiperazine 0.4 wt%, glycine tripeptide 0.2 wt%, glycinamide 0.2 wt%, hydantoin acid 0.15 wt%, hydantoin acid amide 0.15 wt%, ammonia 50 ppm. Immediately heating to 165 ℃ under the stirring state at the speed of 200r/min, preserving the temperature for 1.5 hours, then cooling to about 100 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 688 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction material is 18.31 wt% through ion chromatography analysis, and impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like are not detected, which indicates that the impurities are completely converted into glycine.

Adding 383.06 g (0.84mol) of 35 wt% copper sulfate aqueous solution into the obtained concentrated glycine aqueous solution introduced into a chelation reaction kettle, heating to 55 ℃ under a stirring state to obtain a uniform blue reaction mixed solution, then dropwise adding 25 wt% ammonia water to adjust the pH of the reaction system to be 5.0-5.5, stirring for 60 minutes under a heat preservation condition, carrying out suction filtration on a separated blue precipitate, washing a small amount of water, pouring the solid into a porcelain plate, putting into a forced air drying oven to dry (105 ℃) to constant weight to obtain 176.0 g of blue powdery glycine chelated copper product, wherein the purity is 99.0%, the yield is 98%, the recovery rate of glycine is not less than 98.0%, and concentrating and crystallizing the filtrate to obtain an ammonium sulfate byproduct.

Example 3

700 g of glycine mother liquor having a total nitrogen content of 5.23 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant zirconium-lined reactor having a feed and a stirrer: 21.0 wt% of glycine, 4.0 wt% of glycine dipeptide, 0.3 wt% of hydantoin, 1.0 wt% of diketopiperazine, 1.0 wt% of glycine tripeptide, 0.3 wt% of glycinamide, 0.2 wt% of hydantoin acid amide and 20ppm of ammonia. Heating to 160 ℃ immediately under the condition of stirring at the speed of 150r/min, preserving the temperature for 1.5 hours, cooling to about 100 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 695 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction material is 28.20 wt% through ion chromatography analysis, and impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like are not detected, which indicates that the impurities are completely converted into glycine.

And (3) carrying out steam stripping treatment on the glycine aqueous solution obtained above to remove ammonia and carbon dioxide. Then adding 1.5 g of activated carbon, stirring for 30min at 50 ℃, and then carrying out suction filtration to obtain a decolorized glycine aqueous solution, wherein the color of the aqueous solution is colorless transparent liquid. The decolorized solution was concentrated in a concentration kettle under reduced pressure until the mass percentage of glycine was 30 wt%, to give a concentrated aqueous glycine solution with a weight of 653.3 g (molar weight of glycine 2.6132 mol).

Adding 565.17 g (1.31mol) of 35 wt% manganese sulfate aqueous solution into the obtained concentrated glycine aqueous solution introduced into a chelation reaction kettle, heating to 50 ℃ under a stirring state to obtain a uniform yellow reaction mixed solution, then dropwise adding 25 wt% ammonia water to adjust the pH of the reaction system to 5.5-6.0, keeping the temperature and stirring for 60 minutes, carrying out suction filtration on a separated light yellow precipitate, washing a small amount of water, pouring the solid into a porcelain plate, putting into a forced air drying oven to dry (105 ℃) to constant weight to obtain 263.32 g of light yellow powdery glycine chelated manganese product, wherein the purity is 99.0%, the yield is 98%, the recovery rate of glycine is not less than 98.0%, and concentrating and crystallizing the filtrate to obtain an ammonium sulfate byproduct.

Example 4

700 g of glycine mother liquor having a total nitrogen content of 5.23 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant zirconium-lined reactor having a feed and a stirrer: 21.0 wt% of glycine, 4.0 wt% of glycine dipeptide, 0.3 wt% of hydantoin, 1.0 wt% of diketopiperazine, 1.0 wt% of glycine tripeptide, 0.3 wt% of glycinamide, 0.2 wt% of hydantoin acid amide and 20ppm of ammonia. Heating to 160 ℃ immediately under the condition of stirring at the speed of 100r/min, preserving the temperature for 1.5 hours, cooling to about 100 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 695 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction material is 28.20 wt% through ion chromatography analysis, and impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like are not detected, which indicates that the impurities are completely converted into glycine.

And (3) carrying out steam stripping treatment on the obtained glycine aqueous solution hydrolysate to remove ammonia and carbon dioxide. Then adding 1.5 g of activated carbon, stirring for 30min at 50 ℃, and then carrying out suction filtration to obtain a decolorized glycine aqueous solution, wherein the color of the aqueous solution is colorless transparent liquid. The decolorized solution was concentrated in a concentration kettle under reduced pressure until the mass percentage of glycine was 30 wt%, to give a concentrated aqueous glycine solution with a weight of 653.3 g (molar weight of glycine 2.6132 mol).

Adding 8 g of citric acid and 5 g of reduced iron powder into the obtained concentrated glycine aqueous solution introduced into a chelation reaction kettle, then adding 568.58 g (1.31mol) of 35 wt% ferrous sulfate aqueous solution, heating to 50 ℃ under a stirring state to obtain a gray green reaction mixed solution, then slowly adding 100.98 g of 96 wt% calcium hydroxide under a stirring state, adjusting the pH value of the reaction system to 5.5-6.0, stirring for 60 minutes under a heat preservation condition, carrying out suction filtration on separated white precipitate calcium sulfate, washing with a small amount of water, combining a washing solution and a filtrate, concentrating under a reduced pressure condition until the mixture is almost anhydrous, pouring the solid into a porcelain plate, putting into a vacuum drying oven to dry (105 ℃) to a constant weight to obtain a gray green powdery ferrous glycine chelated product 304.76 g, wherein the purity is 98.0%, the yield is 95%, and the recovery rate of glycine is not less than 95.0%. The infrared spectrum of the ferrous glycine chelated product prepared in this example is shown in figure 3.

Example 5

700 g of glycine mother liquor having a total nitrogen content of 3.36 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant zirconium-lined reactor having a feed and a stirrer: glycine 15.0 wt%, glycine dipeptide 2.0 wt%, hydantoin 0.1 wt%, diketopiperazine 0.5 wt%, glycine tripeptide 0.1 wt%, glycinamide 0.1 wt%, hydantoin acid amide 0.1 wt%, ammonia 40 ppm. Immediately heating to 165 ℃ under the stirring state at the speed of 120r/min, preserving the temperature for 1.5 hours, then cooling to about 100 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 688 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction material is 18.31 wt% through ion chromatography analysis, and impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like are not detected, which indicates that the impurities are completely converted into glycine.

Adding 434.0 g (0.84mol) of 30 wt% cobalt sulfate aqueous solution into the obtained concentrated glycine aqueous solution introduced into a chelation reaction kettle, heating to 60 ℃ under a stirring state to obtain a uniform red reaction mixed solution, then dropwise adding 25 wt% ammonia water to adjust the pH of the reaction system to 6.0-6.5, stirring for 60 minutes at a heat preservation condition, carrying out suction filtration on a separated brick red precipitate, washing a small amount of water, pouring the solid into a porcelain plate, putting into a forced air drying oven to dry (35105 ℃) to constant weight, obtaining 172.16 g of brick red powdery cobalt glycinate chelated product with purity of 99.0%, yield of 98%, recovery rate of glycine of more than or equal to 98.0%, and concentrating and crystallizing the filtrate to obtain an ammonium sulfate byproduct.

Example 6

700 g of glycine mother liquor having a total nitrogen content of 3.36 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant zirconium-lined reactor having a feed and a stirrer: glycine 15.0 wt%, glycine dipeptide 2.0 wt%, hydantoin 0.1 wt%, diketopiperazine 0.5 wt%, glycine tripeptide 0.1 wt%, glycinamide 0.1 wt%, hydantoin acid amide 0.1 wt%, ammonia 40 ppm. Immediately heating to 165 ℃ under the stirring state at the speed of 200r/min, preserving the temperature for 1.5 hours, then cooling to about 100 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 688 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction material is 18.31 wt% through ion chromatography analysis, and impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like are not detected, which indicates that the impurities are completely converted into glycine.

And (3) carrying out steam stripping treatment on the obtained glycine aqueous solution hydrolysate to remove ammonia and carbon dioxide. Then adding 1 g of activated carbon, stirring for 30min at 50 ℃, and then carrying out suction filtration to obtain a decolorized glycine aqueous solution, wherein the color of the aqueous solution is colorless transparent liquid. The decolorized solution was concentrated in a concentration kettle under reduced pressure until the mass percentage of glycine was 32 wt%, to give a concentrated aqueous glycine solution having a weight of 393.67 g (molar amount of glycine: 1.68 mol).

Adding 382.34 g (0.84mol) of 34 wt% nickel sulfate aqueous solution into the obtained concentrated glycine aqueous solution introduced into a chelation reaction kettle, heating to 60 ℃ under a stirring state to obtain a uniform green reaction mixed solution, then dropwise adding 25 wt% ammonia water to adjust the pH of the reaction system to 6.0-6.5, keeping the temperature and stirring for 60 minutes, carrying out suction filtration on a separated gray green precipitate, washing a small amount of water, pouring the solid into a porcelain plate, putting into a forced air drying box to dry (105 ℃) to constant weight to obtain 201.90 g of gray green powdery glycine chelated nickel product, wherein the purity is 99.0%, the yield is 98%, the recovery rate of glycine is not less than 98.0%, and concentrating and crystallizing the filtrate to obtain an ammonium sulfate byproduct.

Example 7

700 g of glycine mother liquor having a total nitrogen content of 3.36 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant zirconium-lined reactor having a feed and a stirrer: glycine 15.0 wt%, glycine dipeptide 2.0 wt%, hydantoin 0.1 wt%, diketopiperazine 0.5 wt%, glycine tripeptide 0.1 wt%, glycinamide 0.1 wt%, hydantoin acid amide 0.1 wt%, ammonia 40 ppm. Immediately heating to 165 ℃ under the stirring state at the speed of 100r/min, preserving the temperature for 1.5 hours, then cooling to about 100 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 688 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction material is 18.31 wt% through ion chromatography analysis, and impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like are not detected, which indicates that the impurities are completely converted into glycine.

Adding 327.11 g (0.84mol) of 35 wt% zinc chloride aqueous solution into the obtained concentrated glycine aqueous solution introduced into a chelation reaction kettle, heating to 55 ℃ under a stirring state to obtain a uniform reaction mixed solution, then dropwise adding 25 wt% ammonia water to adjust the pH of the reaction system to 5.5-6.0, stirring for 80 minutes at a heat preservation temperature, carrying out suction filtration on a separated white precipitate, washing a small amount of water, pouring the solid into a porcelain plate, putting into a forced air drying oven to dry (105 ℃) to constant weight to obtain 174.80 g of white powdery glycine chelated zinc product, wherein the purity is 98.5%, the yield is 96%, the recovery rate of glycine is not less than 95.0%, and concentrating and crystallizing the filtrate to obtain an ammonium chloride byproduct.

Example 8

700 g of glycine mother liquor having a total nitrogen content of 3.36 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant zirconium-lined reactor having a feed and a stirrer: glycine 15.0 wt%, glycine dipeptide 2.0 wt%, hydantoin 0.1 wt%, diketopiperazine 0.5 wt%, glycine tripeptide 0.1 wt%, glycinamide 0.1 wt%, hydantoin acid amide 0.1 wt%, ammonia 40 ppm. Immediately heating to 165 ℃ under the stirring state at the speed of 90r/min, preserving the temperature for 1.5 hours, then cooling to about 100 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 688 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction material is 18.31 wt% through ion chromatography analysis, and impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like are not detected, which indicates that the impurities are completely converted into glycine.

And (3) carrying out steam stripping treatment on the obtained glycine aqueous solution hydrolysate to remove ammonia and carbon dioxide. Then adding 1 g of activated carbon into the glycine aqueous solution, stirring for 30min at 50 ℃, and then carrying out suction filtration to obtain a decolorized glycine aqueous solution, wherein the color of the aqueous solution is colorless transparent liquid. The decolorized solution was concentrated in a concentration kettle under reduced pressure until the mass percentage of glycine was 32 wt%, to give a concentrated aqueous glycine solution having a weight of 393.67 g (molar amount of glycine: 1.68 mol).

Adding 481.63 g (0.84mol) of 32 wt% zinc acetate aqueous solution into the obtained concentrated glycine aqueous solution introduced into a chelation reaction kettle, heating to 55 ℃ under a stirring state to obtain a uniform reaction mixed solution, then dropwise adding 25 wt% ammonia water to adjust the pH of the reaction system to be 6.0-6.5, keeping the temperature and stirring for 80 minutes, carrying out suction filtration on a separated white precipitate, washing a small amount of water, pouring the solid into a porcelain plate, putting into a forced air drying oven to dry (105 ℃) to constant weight to obtain 174.80 g of white powdery glycine chelated zinc product, wherein the purity is 98.5%, the yield is 96%, the recovery rate of glycine is not less than 95.0%, and concentrating and crystallizing the filtrate to obtain an ammonium acetate byproduct.

Example 9

700 g of glycine mother liquor having a total nitrogen content of 3.36 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant zirconium-lined reactor having a feed and a stirrer: glycine 15.0 wt%, glycine dipeptide 2.0 wt%, hydantoin 0.1 wt%, diketopiperazine 0.5 wt%, glycine tripeptide 0.1 wt%, glycinamide 0.1 wt%, hydantoin acid amide 0.1 wt%, ammonia 40 ppm. Immediately heating to 165 ℃ under the stirring state at the speed of 110r/min, preserving the temperature for 1.5 hours, then cooling to about 100 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 688 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction material is 18.31 wt% through ion chromatography analysis, and impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like are not detected, which indicates that the impurities are completely converted into glycine.

Adding 313.72 g (0.84mol) of 36 wt% copper chloride aqueous solution into the obtained concentrated glycine aqueous solution introduced into a chelation reaction kettle, heating to 55 ℃ under a stirring state to obtain a uniform blue reaction mixed solution, then dropwise adding 25 wt% ammonia water to adjust the pH of the reaction system to 5.0-5.5, keeping the temperature and stirring for 60 minutes, carrying out suction filtration on the separated blue precipitate, washing a small amount of water, pouring the solid into a porcelain plate, putting into a forced air drying oven to dry (105 ℃) to constant weight to obtain 176.0 g of blue powdery glycine chelated copper product, wherein the purity is 99.0%, the yield is 98%, the recovery rate of glycine is not less than 98.0%, and concentrating and crystallizing the filtrate to obtain an ammonium chloride byproduct.

Example 10

700 g of glycine mother liquor having a total nitrogen content of 3.36 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant zirconium-lined reactor having a feed and a stirrer: glycine 15.0 wt%, glycine dipeptide 2.0 wt%, hydantoin 0.1 wt%, diketopiperazine 0.5 wt%, glycine tripeptide 0.1 wt%, glycinamide 0.1 wt%, hydantoin acid amide 0.1 wt%, ammonia 45 ppm. Immediately heating to 165 ℃ under the stirring condition at the speed of 180r/min, preserving the temperature for 1.5 hours, then cooling to about 100 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, and cooling to room temperature to obtain 688 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction material is 18.31 wt% through ion chromatography analysis, impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like are not detected, and the impurities are indicated to be completely converted into glycine.

Adding 508.57 g (0.84mol) of 30 wt% copper acetate aqueous solution into the obtained concentrated glycine aqueous solution introduced into a chelation reaction kettle, heating to 55 ℃ under a stirring state to obtain a uniform blue reaction mixed solution, then dropwise adding 25 wt% ammonia water to adjust the pH of the reaction system to 5.0-5.5, keeping the temperature and stirring for 60 minutes, carrying out suction filtration on the separated blue precipitate, washing a small amount of water, pouring the solid into a porcelain plate, putting into a forced air drying oven to dry (105 ℃) to constant weight to obtain 176.0 g of blue powdery glycine chelated copper product, wherein the purity is 99.0%, the yield is 98%, the recovery rate of glycine is not less than 98.0%, and concentrating and crystallizing the filtrate to obtain an ammonium acetate byproduct.

Example 11

700 g of glycine mother liquor having a total nitrogen content of 5.23 wt.% and 0.35 g of metallic zirconium powder were introduced into a 1000ml pressure-resistant reactor (material 316L) having a feed and stirring device, the contents of the individual components being: glycine 24.2 wt%, glycine dipeptide 2.0 wt%, hydantoin 0.3 wt%, diketopiperazine 0.5 wt%, glycine tripeptide 0.4 wt%, glycinamide 0.3 wt%, hydantoin acid 0.2 wt%, hydantoin acid amide 0.1 wt%, ammonia 25 ppm. Wherein the amount of the zirconium is 500ppm of the mass of the glycine mother liquor based on the mass of the zirconium element. Heating to 160 ℃ immediately under the condition of stirring at the speed of 120r/min, stirring and preserving heat for 1.5 hours, cooling to about 100 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 698 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction material is 28.10 wt% through ion chromatography analysis, and impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like are not detected, which indicates that the impurities are completely converted into glycine.

And (3) carrying out steam stripping treatment on the glycine aqueous solution obtained above to remove ammonia and carbon dioxide. Then 2.2 g of activated carbon is added into the solution, the solution is stirred for 40min at the temperature of 70 ℃, and then the decolored glycine aqueous solution is obtained by suction filtration, and the color of the aqueous solution is colorless transparent liquid. The decolorized solution was concentrated in a concentration kettle under reduced pressure until the mass percentage of glycine was 35 wt%, yielding a concentrated glycine aqueous solution with a weight of 560.39 g (molar weight of glycine: 2.615 mol).

Adding 639.68 g (1.3075mol) of 33 wt% zinc sulfate aqueous solution into the obtained concentrated glycine aqueous solution introduced into a chelation reaction kettle, heating to 55 ℃ under a stirring state to obtain a uniform reaction mixed solution, then dropwise adding 25 wt% ammonia water to adjust the pH of the reaction system to be 5.5-6.0, stirring for 80 minutes under a heat preservation condition, carrying out suction filtration on a separated white precipitate, washing a small amount of water, pouring the solid into a porcelain plate, putting into a forced air drying oven to dry (105 ℃) to constant weight to obtain 174.80 g of white powdery glycine chelated zinc product, wherein the purity is 98.5%, the yield is 96%, the recovery rate of glycine is not less than 95.0%, and concentrating and crystallizing the filtrate to obtain an ammonium sulfate byproduct. The IR spectrum of the zinc glycine chelate product prepared in this example is shown in FIG. 2.

Comparative example 1

700 g of glycine mother liquor having a total nitrogen content of 5.23 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant reactor (material 316L) having a feed and a stirrer: glycine 24.2 wt%, glycine dipeptide 1.5 wt%, hydantoin 0.5 wt%, diketopiperazine 0.2 wt%, glycine tripeptide 0.6 wt%, glycinamide 0.6 wt%, hydantoin 0.3 wt%, hydantoin 0.1 wt% (total impurities 3.8 wt%), ammonia 30 ppm. Heating to 160 ℃ immediately under the condition of stirring at the speed of 200r/min, keeping the temperature for 1.5 hours to perform hydrolysis reaction (the pressure is 2.2MPa), then cooling to about 100 ℃, decompressing to the normal pressure, pouring the reaction material into a beaker, cooling to the room temperature to obtain 700 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction material is 20.8 wt% by ion chromatography, the total content of impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like in the hydrolysis solution is 7.2 wt% by ion chromatography, and the glycine aqueous solution is partially condensed and dehydrated under the high-temperature condition to be converted into compounds such as dipeptide, tripeptide and the like, and the impurities are not hydrolyzed to form glycine under the condition of comparative example 1.

Comparative example 2

700 g of glycine mother liquor having a total nitrogen content of 5.23 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant reactor (material 316L) having a feed and a stirrer: glycine 24.2 wt%, glycine dipeptide 1.5 wt%, hydantoin 0.5 wt%, diketopiperazine 0.2 wt%, glycine tripeptide 0.6 wt%, glycinamide 0.6 wt%, hydantoin 0.3 wt%, hydantoin 0.1 wt% (total impurities 3.8 wt%), ammonia 20 ppm. Immediately heating to 100 ℃ under stirring at a speed of 200r/min and keeping the temperature for 1.5 hours to perform hydrolysis reaction (pressure of 2.2MPa), then cooling to about 50 ℃, decompressing to normal pressure, pouring the reaction materials into a beaker, cooling to room temperature to obtain 700 g of glycine aqueous solution, the aqueous solution is yellowish brown, the mass percent of glycine in the reaction material is 23.0 wt%, and the total content of impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like in the hydrolysis solution is 5.0 wt% detected by ion chromatography, which indicates that only a small amount of condensation dehydration of the aqueous glycine solution at a relatively low temperature (within 100 ℃) will convert the aqueous glycine solution into compounds such as dipeptide, tripeptide and the like, and the impurities are not hydrolyzed to form glycine under the conditions of comparative example 2.

Comparative example 3

700 g of glycine mother liquor having a total nitrogen content of 5.23 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant reactor (material 316L) having a feed and a stirrer: glycine 24.2 wt%, glycine dipeptide 1.5 wt%, hydantoin 0.5 wt%, diketopiperazine 0.2 wt%, glycine tripeptide 0.6 wt%, glycinamide 0.6 wt%, hydantoin 0.3 wt%, hydantoin 0.1 wt% (total impurities 3.8 wt%), ammonia 30 ppm. Immediately heating to 80 ℃ under stirring at a speed of 200r/min and keeping the temperature for 1.5 hours to perform hydrolysis reaction (pressure of 2.2MPa), then cooling to about 50 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 700 g of glycine aqueous solution, the aqueous solution is yellowish brown, the mass percent of glycine in the reaction material is 24.0 wt% through ion chromatography, and the total content of impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like in the hydrolysis solution is detected to be 4.0 wt% through ion chromatography, which shows that the aqueous solution of glycine has a small amount of impurities which are condensed and dehydrated to be converted into compounds such as dipeptide, tripeptide and the like under the relatively low temperature condition (within 90 ℃), and the impurities are not hydrolyzed to form glycine under the condition of comparative example 3.

Comparative example 4

700 g of glycine mother liquor having a total nitrogen content of 5.23 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant reactor (material 316L) having a feed and a stirrer: glycine 24.2 wt%, glycine dipeptide 1.5 wt%, hydantoin 0.5 wt%, diketopiperazine 0.2 wt%, glycine tripeptide 0.6 wt%, glycinamide 0.6 wt%, hydantoin 0.3 wt%, hydantoin 0.1 wt% (total impurities 3.8 wt%), ammonia 30 ppm. Heating to 65 ℃ immediately under the condition of stirring at the speed of 200r/min, keeping the temperature for 1.5 hours, cooling to about 50 ℃, relieving the pressure to normal pressure, pouring the reaction materials into a beaker, cooling to room temperature to obtain 700 g of glycine aqueous solution, wherein the aqueous solution is yellowish brown, the mass percentage of glycine in the reaction materials is 24.2 wt% by ion chromatography, and the content of impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycine amide, hydantoin acid amide and the like in the hydrolysis solution is detected to be 3.8 wt% by ion chromatography, which shows that glycine is not condensed and dehydrated to be converted into dipeptide, tripeptide and the like under the relatively low temperature condition (within 80 ℃), and the impurities are not hydrolyzed to form glycine under the condition of comparative example 4.

Comparative example 5

700 g of glycine mother liquor having a total nitrogen content of 5.23 wt.% and consisting of the following constituents were introduced into a 1000ml pressure-resistant reactor (material 316L) having a feed and a stirrer: glycine 24.2 wt%, glycine dipeptide 1.5 wt%, hydantoin 0.5 wt%, diketopiperazine 0.2 wt%, glycine tripeptide 0.6 wt%, glycinamide 0.6 wt%, hydantoin 0.3 wt%, hydantoin 0.1 wt% (total impurities 3.8 wt%), ammonia 30 ppm. 209.2 g of 50% by weight aqueous sodium hydroxide solution (2.615mol) were then added. Immediately heating to 120 ℃ under the stirring state at the speed of 200r/min, preserving the heat for 1.5 hours, then cooling to about 50 ℃, decompressing to normal pressure, pouring the reaction material into a beaker, cooling to room temperature to obtain 905 g of sodium glycinate aqueous solution, the aqueous solution is brown yellow, the mass percentage of the glycine in the reaction materials is 20.73 wt% through ion chromatography, impurities such as glycine dipeptide, hydantoin, diketopiperazine, glycine tripeptide, glycinamide, hydantoin acid amide and the like in the hydrolysate are detected through ion chromatography, hydantoin, diketopiperazine, hydantoin acid and hydantoin acid amide are not detected, however, when glycine dipeptide and glycine tripeptide were detected and the total content of both was 0.93 wt%, it was found that impurities in the glycine mother liquor could not be completely converted into glycine when the glycine mother liquor was hydrolyzed under heating by adding an equimolar amount of sodium hydroxide (based on the total nitrogen content in the mother liquor).

Finally, the above embodiments are only for illustrating the technical solutions of the present invention and not for limiting, although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all of them should be covered in the claims of the present invention.

Claims

1. A comprehensive utilization method of glycine crystallization mother liquor by a hydantoin method comprises the following steps:

2. The method of claim 1, wherein in step (1), the total nitrogen content of the glycine crystallization mother liquor is 1.20-7.5 wt%, preferably 3.0-5.5 wt%;

preferably, the glycine crystallization mother liquor comprises the following components in percentage by mass: 5-30 parts of glycine, 0.5-4.0 parts of glycine dipeptide, 0.1-0.8 part of glycine tripeptide, 0.1-2.0 parts of hydantoin, 0.2-1.0 part of diketopiperazine, 0.1-1.0 part of glycinamide, 0.05-0.3 part of hydantoin, 0.05-0.2 part of hydantoin amide, 50ppm or less of ammonia and the balance of water;

preferably, the method further comprises producing the hydantoin process glycine mother liquor by: feeding hydroxyl acetonitrile, ammonia, carbon dioxide and water according to a molar feeding ratio of 1:6:3 (44-46), wherein the reaction temperature is 140-160 ℃, and the reaction time is 2-3 hours; after the reaction is finished, removing carbon dioxide and ammonia which do not participate in the reaction through steam stripping to obtain a dilute glycine solution; decoloring, concentrating, cooling and crystallizing to obtain a crude glycine as a light yellow crystal, and separating the crude glycine to obtain a crystallization mother liquor as the hydantoin-method glycine crystallization mother liquor;

preferably, the method further comprises producing the hydantoin process glycine crystallization mother liquor by: adding water into the glycine crude product for recrystallization, separating recrystallized glycine to obtain recrystallization mother liquor, and taking the single recrystallization mother liquor or the mixture of the recrystallization mother liquor and the crystallization mother liquor as the hydantoin-process glycine crystallization mother liquor;

preferably, in step (1), the zirconium feedstock may be in the form of a reactor lining, a briquette or a powder;

preferably, in step (1), the zirconium-containing alloy is an alloy having a zirconium content of 5 wt% to 30 wt%; preferably, the zirconium-containing alloy is a zirconium-iron alloy, a zirconium-cobalt alloy, a zirconium-copper alloy, a zirconium-tin alloy, a zirconium-aluminum alloy, a zirconium-niobium alloy, or any mixture thereof;

preferably, in step (1), the zirconium salt is an inorganic zirconium salt; preferably, the inorganic zirconium salt comprises zirconium sulfate, zirconium chloride, zirconium carbonate, zirconium nitrate, zirconium phosphate, zirconium acetate, or any mixture thereof;

preferably, in the step (1), the adding amount of the zirconium raw material is 20-500 ppm of the mass of the hydantoin-process glycine crystallization mother liquor based on the mass of zirconium element;

preferably, in the step (1), the hydrolysis reaction is carried out by heating to 150-170 ℃ and keeping the temperature for 30-90 min with stirring at the speed of 60-200 r/min;

preferably, in the step (1), the pressure of the hydrolysis reaction is 1.2-3.0 MPa.

3. The process according to claim 1 or 2, wherein, in step (2), the glycine aqueous solution of step (1) is subjected to a stripping treatment to remove ammonia and carbon dioxide;

preferably, in the step (2), activated carbon or a nanofiltration membrane is used for the decolorization treatment;

preferably, the using amount of the activated carbon is 0.2-1.0 wt% of the total mass of the glycine in the glycine aqueous solution;

preferably, the temperature of the decoloring treatment is 40-70 ℃, and the time is 20-40 min;

preferably, in the step (2), the mass percentage of glycine in the concentrated glycine aqueous solution is 15.0 wt% to 32.0 wt%.

4. A process according to any one of claims 1 to 3, wherein in step (3) the charged molar ratio of glycine to inorganic metal salt in the concentrated aqueous glycine solution is 2: 1;

preferably, in step (3), the inorganic metal salt is an anhydrous compound or hydrate of zinc sulfate, zinc chloride, zinc acetate, copper sulfate, copper chloride, copper acetate, manganese sulfate, manganese chloride, manganese acetate, nickel sulfate, nickel chloride, cobalt sulfate, cobalt chloride, cobalt acetate, ferrous sulfate, or any mixture thereof; preferably, the inorganic metal salt is in the form of an aqueous solution thereof, particularly preferably a saturated aqueous solution;

preferably, in step (3), the pH adjusting agent is a base, preferably an inorganic base; preferably, the alkali is one or more of sodium carbonate, potassium carbonate, lithium carbonate, sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium oxide, calcium hydroxide, ammonia gas and ammonia water, preferably ammonia water, calcium oxide and calcium hydroxide;

preferably, in the step (3), the temperature of the chelation reaction is 40-70 ℃, preferably 50-65 ℃, and the time is 90-120 min, preferably 90-100 min;

preferably, in the step (3), the solid precipitate and the supernatant after the chelation reaction are separated by suction filtration or centrifugation;

preferably, in the step (3), the glycine metal chelate is any one or more of zinc glycine chelate, ferrous glycine chelate, copper glycine chelate, manganese glycine chelate, nickel glycine chelate and cobalt glycine chelate;

preferably, in step (3), the chemical structure of the glycine metal chelate is as follows:

5. the method according to any one of claims 1 to 4, wherein, in the step (3), when the glycine metal chelate is one or more of zinc glycine chelate, copper glycine chelate, manganese glycine chelate, nickel glycine chelate and cobalt glycine chelate, the solid precipitate after the chelation reaction is separated, washed and dried to obtain a glycine metal chelate; preferably, the filtrate obtained by separation is concentrated and crystallized to obtain one or more of ammonium sulfate, ammonium chloride and ammonium acetate as byproducts; preferably, the pH regulator is ammonia water;

or, in the step (3), when the glycine metal chelate is glycine chelated ferrous iron, separating, concentrating and drying the supernatant after chelation reaction to obtain glycine metal chelate; preferably, the solid precipitate obtained by separation (for example calcium sulphate) is used as a by-product;

preferably, mixing the concentrated glycine aqueous solution of step (2) with ferrous sulfate and a complex oxidant to prepare ferrous glycine chelate; preferably, the feeding molar ratio of glycine to ferrous sulfate in the concentrated glycine aqueous solution is 2: 1; preferably, the composite oxidant is citric acid and reduced iron powder; preferably, the feeding amount of the composite oxidant is 5-10 wt% of the mass of the glycine; preferably, the pH adjuster is an alkali, preferably one or both of calcium oxide and calcium hydroxide.

6. The method according to any one of claims 1-5, wherein the method comprises the steps of:

(ii) carrying out steam stripping treatment on the obtained glycine aqueous solution to remove ammonia and carbon dioxide to obtain feed liquid (I); adding active carbon into the feed liquid (I) for decoloring, wherein the adding amount of the active carbon is 0.2-1.0 wt% of the total mass of the glycine, the decoloring temperature is 40-70 ℃, and the time is 20-40 min, removing the active carbon after the decoloring is finished, and performing reduced pressure concentration treatment on the decolored feed liquid to obtain a concentrated glycine aqueous solution;

or when the glycine metal chelate is glycine chelated ferrous iron, mixing the concentrated glycine aqueous solution obtained in the step (ii) with a ferrous sulfate aqueous solution and a composite oxidant (preferably citric acid and reduced iron powder), then adding calcium oxide or calcium hydroxide to adjust the pH value of the reaction system to 5.5-6.5, wherein the feeding amount of the composite oxidant is 5-10 wt% of the mass of glycine, the reaction temperature is 50-65 ℃, the reaction time is 90-100 min, separating calcium sulfate, and directly performing spray drying on the filtrate to obtain glycine chelated ferrous iron;

preferably, the process is one or more of a batch, semi-continuous or continuous, preferably a semi-continuous or continuous operating process.

7. A glycine metal chelate prepared by the process of any one of claims 1 to 6.

8. A feed additive comprising a glycine metal chelate prepared by the method of any one of claims 1-6;

preferably, the glycine metal chelate is any one or more of zinc glycine chelate, ferrous glycine chelate, copper glycine chelate, manganese glycine chelate, nickel glycine chelate and cobalt glycine chelate;

preferably, the chemical structure of the glycine metal chelate is as follows:

preferably, the feed additive further comprises a feedinglogically acceptable auxiliary material.

9. An apparatus for carrying out the method of any one of claims 1-6, wherein the apparatus comprises a hydrolysis reactor, a stripping column, a decolorization tank, a concentration tank, a chelation tank, a separation system, and a drying system connected in series in fluid communication.

10. The apparatus of claim 9, wherein the hydrolysis reactor and the concentration tank are respectively provided with a pressure device;

preferably, the hydrolysis reactor, the concentration kettle, the chelation reaction kettle and the drying system are respectively provided with a temperature adjusting auxiliary device;

preferably, the drying system is a double cone dryer or a spray drying system;

preferably, the separation system comprises one or more of a centrifuge, a filter flask, a buchner funnel, a vacuum circulating pump.