阅读说明：本技术 一种低寡聚体羟基蛋氨酸金属螯合物的制备方法 (Preparation method of low-oligomer hydroxymethionine metal chelate ) 是由 周荣超 廖常福 吴传隆 彭启明 周振宇 于 2020-12-30 设计创作，主要内容包括：本发明涉及有机络合物制备技术领域,尤其涉及一种低寡聚体羟基蛋氨酸金属螯合物的制备方法,通过将高浓度羟基蛋氨酸稀释后与氨混合,在一定温度压力下转化为单体羟基蛋氨酸铵盐,并在反应完毕回收多余氨气,单体羟基蛋氨酸铵盐再与金属化合物在加热下反应制备羟基蛋氨酸金属螯合物或钙,最后得到羟基蛋氨酸金属螯合物或钙产物溶液,降温析晶分离后,固体洗涤烘干得到羟基蛋氨酸金属螯合物产品,洗液与母液合并用作高浓度羟基蛋氨酸稀释。本发明的制备方法可制备得到高纯度的单体羟基蛋氨酸金属螯合物,消除了二聚体、多聚体对产品质量影响,且整个过程氨被使用和回收,不产生多余副产物,清洁可持续,工艺简单紧凑,具有较高的产物收率。(The invention relates to the technical field of organic complex preparation, in particular to a preparation method of low-oligomer hydroxymethionine metal chelate, which comprises the steps of diluting high-concentration hydroxymethionine, mixing the diluted hydroxymethionine with ammonia, converting the mixture into monomer hydroxymethionine ammonium salt at a certain temperature and pressure, recovering redundant ammonia after the reaction is finished, reacting the monomer hydroxymethionine ammonium salt with a metal compound under heating to prepare hydroxymethionine metal chelate or calcium, finally obtaining a hydroxymethionine metal chelate or calcium product solution, cooling, crystallizing and separating, washing and drying the solid to obtain a hydroxymethionine metal chelate product, and combining a washing solution and a mother solution to dilute the high-concentration hydroxymethionine. The preparation method can prepare the high-purity monomer hydroxymethionine metal chelate, eliminates the influence of dimer and polymer on the product quality, uses and recovers ammonia in the whole process, does not generate redundant byproducts, is clean and sustainable, has simple and compact process and higher product yield.)

1. The preparation method of the low-oligomer hydroxymethionine metal chelate is characterized in that hydroxymethionine is diluted and then hydrolyzed and neutralized under the action of ammonia to generate a monomer hydroxymethionine ammonium salt solution with the hydroxymethionine oligomer content lower than 1 w%, and the monomer hydroxymethionine ammonium salt solution is reacted with a metal compound to generate the hydroxymethionine metal chelate.

2. The method of claim 1, wherein the method comprises the steps of:

s1, diluting high-concentration hydroxy methionine, adding ammonia, carrying out hydrolysis neutralization reaction for 45-60 min at 160-200 ℃, and then cooling to remove ammonia gas to obtain monomer hydroxy methionine ammonium salt reaction liquid;

s2, adding a metal compound into the reaction liquid obtained by the reaction in the step S1, controlling the temperature to be 70-105 ℃, reacting for 90-150 min, stirring, and naturally cooling to obtain a hydroxymethionine metal chelate suspension;

s3, carrying out suction filtration on the hydroxymethionine metal chelate suspension to obtain a solid and a mother solution, washing the solid with distilled water, combining the washed filtrate with the mother solution, and drying the washed solid to obtain a hydroxymethionine metal chelate product.

3. The method for preparing low-oligomer hydroxymethionine metal chelate according to claim 2, wherein the step of adding ammonia after the high-concentration hydroxymethionine is to add ammonia water to the high-concentration hydroxymethionine or to add water to the high-concentration hydroxymethionine for dilution, and then to introduce ammonia gas into the closed environment; the dilution concentration of the hydroxymethionine is 20-50%.

4. The method of claim 2, wherein the charged molar ratio of ammonia to hydroxymethionine in step S1 is 4-10: 1.

5. The method of claim 2, wherein the high concentration of hydroxymethionine is 88 wt% of commercial grade hydroxymethionine or a concentrated solution of hydroxymethionine with a concentration of 88-100 wt%, wherein the ammonium sulfate salt is less than 0.6%.

6. The method of claim 2, wherein the metal compound is one of an oxide or hydroxide of zinc, copper, magnesium, calcium.

7. The method of claim 6, wherein the metal compound is added in an amount such that the molar ratio of metal ions to hydroxymethionine is 1: 1.9-2.1, and the molar ratio of the metal ions to the free ammonia in the reaction system of the step S2 is 1: 4-6.

8. The method of claim 2, wherein the filtrate from the step of S3 is combined with the mother liquor to be diluted with high-concentration hydroxymethionine from the step of S1.

9. The method for preparing low-oligomer hydroxymethionine metal chelate according to claim 2, wherein the hydrolysis neutralization reaction is performed in a reaction kettle, the reaction kettle is one of 304, 304L, 316L and 316 high-pressure reaction kettles containing zirconium materials, and the pressure during the hydrolysis neutralization reaction is controlled to be 0.8-1.8 MPa.

10. The method of claim 2, wherein the ammonia gas removed after the hydrolysis neutralization reaction is recovered and used in the hydrolysis neutralization reaction of the hydroxymethionine of the next batch.

Technical Field

The invention relates to the technical field of organic complex preparation, in particular to a preparation method of a low-oligomer hydroxymethionine metal chelate.

Background

The methionine series chelate is a compound which reacts the trace elements necessary for the growth of animals with methionine to generate a chelate state, and is a trace element supplement which is close to the natural form in the bodies of the animals. Compared with inorganic salt, the compound feed additive has good chemical stability and biochemical stability, and is an ideal high-efficiency feed additive.

Zinc hydroxymethionine chelate, copper hydroxymethionine chelate and calcium hydroxymethionine are high-quality nutrients of amino acid methionine and calcium, copper and zinc elements necessary for animal body supplement, and are prepared by respectively reacting liquid methionine with calcium salt, copper salt and zinc salt according to the molar ratio of 2: 1. According to whether the chemical state of the hydroxymethionine in the hydroxymethionine chelated zinc, copper and calcium products is a monomer or a mixture of the monomer, a dimer and a polymer, the product quality can be roughly distinguished, and the structural formula of the main component of the oligomer in the hydroxymethionine is shown in figure 1. Most feed-grade liquid calcium methionine, chelated zinc and chelated copper are mostly chelated products of a mixture of a hydroxymethionine monomer and a polymer, most of the products are prepared by directly reacting commercial-grade hydroxymethionine with zinc salt, copper salt and calcium salt, and the products with uniform physical distribution are obtained under the help of physical equipment, auxiliary reagents and the like. The zinc hydroxymethionine chelate, the copper hydroxymethionine chelate and the calcium hydroxymethionine chelate which are used as food-grade and medical-grade are highly uniform monomer hydroxymethionine chelate products, but the preparation processes published at present are complex, and have the problems of low yield, high cost, uncleanness, environmental protection and the like which influence industrial application.

Chinese patent CN103641757 discloses that D, L-2-hydroxy-4-methylthiobutyronitrile is hydrolyzed into D, L-2-hydroxy-4-methylthio butyrate under the catalysis of alkali, and then the D, L-2-hydroxy-4-methylthio butyrate is prepared by reacting with soluble calcium salt.

Chinese patent CN102399176 discloses that D, L-2-hydroxy-4-methylthiobutyronitrile is hydrolyzed under concentrated hydrochloric acid, neutralized by 30% NaOH and crystallized to obtain D, L-2-hydroxy-4-methylthio butyronitrile, and the amide reacts with excessive calcium hydroxide to prepare calcium D, L-2-hydroxy-4-methylthio butyrate; chinese patent CN101348451 discloses that D, L-2-hydroxy-4-methylthio butyric acid reacts with alcohol to form ester under the catalysis of sulfuric acid or benzenesulfonic acid, and the obtained ester is hydrolyzed with calcium oxide to prepare the calcium D, L-2-hydroxy-4-methylthio butyrate. These processes, which react with calcium oxide or calcium hydroxide in the form of hydroxymethionine amides or esters, present difficulties in achieving complete reaction and produce inorganic salts or catalysts which are not recyclable.

Chinese patent CN1235878 discloses that liquid methionine and zinc oxide aqueous solution react at a molar ratio of 1:1 at 80-90 ℃ and pH 6-8 to prepare alkaline liquid zinc methionine. The method is simple and direct, has no byproduct salt, is clean and efficient, but still does not solve the problem that polymers in the liquid methionine influence the reaction and the final quality of the product, and the five-membered ring complex formed by liquid methionine hydroxyl, carboxyl and zinc is prepared by the liquid methionine and zinc oxide according to the molar ratio of 1:1, and the complex has low complexing strength.

In summary, the current preparation technology based on hydroxymethionine chelated zinc and calcium has the following disadvantages: firstly, the oligomer contained in the liquid methionine raw material causes low product quality, such as low content of metal elements or entrainment of metal raw material salt; secondly, the hydroxymethionine is purified by converting other intermediate products, so that the process is complex, the yield is low, the cost is high, and a large amount of salt and wastewater are mostly byproduct; thirdly, the structure of the product of the hydroxyl methionine complex formed by single molecule is not stable enough.

Disclosure of Invention

In view of the above, the present invention provides a method for preparing low-oligomer hydroxymethionine metal chelate, which can obtain high-purity monomelic hydroxymethionine metal chelate, eliminate the influence of dimer and polymer on product quality, and the ammonia is used and recovered in the whole process, so that no unnecessary by-products are generated, the method is clean and sustainable, the process is simple and compact, and the product yield is high.

The invention solves the technical problems by the following technical means:

a preparation method of low-oligomer hydroxymethionine metal chelate comprises the steps of diluting hydroxymethionine, hydrolyzing and neutralizing under the action of ammonia to generate monomer hydroxymethionine ammonium salt solution with the content of hydroxymethionine oligomer lower than 1 w%, and reacting the monomer hydroxymethionine ammonium salt solution with metal compounds to generate the hydroxymethionine metal chelate.

Preferably, the preparation method comprises the following steps:

s1, diluting high-concentration hydroxy methionine, adding ammonia, carrying out hydrolysis neutralization reaction for 45-60 min at 160-200 ℃, and then cooling to remove ammonia gas to obtain monomer hydroxy methionine ammonium salt reaction liquid;

s2, adding a metal compound into the reaction liquid obtained by the reaction in the step S1, controlling the temperature to be 70-105 ℃, reacting for 90-150 min, stirring, and naturally cooling to obtain a hydroxymethionine metal chelate suspension;

s3, carrying out suction filtration on the hydroxymethionine metal chelate suspension to obtain a solid and a mother solution, washing the solid with distilled water, combining the washed filtrate with the mother solution, and drying the washed solid to obtain a hydroxymethionine metal chelate product.

Preferably, the operation of adding ammonia after the high-concentration hydroxymethionine is diluted is to add ammonia water into the high-concentration hydroxymethionine, or add water into the high-concentration hydroxymethionine for dilution, and introduce ammonia gas into a closed environment; the dilution concentration of the hydroxymethionine is 20-50%.

Preferably, the feeding molar ratio of ammonia to hydroxymethionine in the step S1 is 4-10: 1.

Preferably, the high-concentration hydroxymethionine is 88 wt% of commercial-grade hydroxymethionine or a concentrated solution of hydroxymethionine with the concentration of 88-100 wt%, wherein the ammonium sulfate salt is less than 0.6%.

Preferably, the metal compound is one of oxides or hydroxides of zinc, copper, magnesium and calcium.

Preferably, in the step S2, the metal compound is added in an amount such that the molar ratio of the metal ion to the hydroxymethionine is 1: 1.9-2.1, and the molar ratio of the metal ions to the free ammonia in the reaction system of the step S2 is 1: 4-6, so that the metal compound and the ammonia can form a soluble complex, and the reaction of the hydroxy methionine salt and the metal ions is facilitated to generate methionine chelate. For example, in the reaction system for generating the zinc hydroxy methionine chelate, the following reaction occurs between ammonia and zinc oxide:

ZnO+NH₃·H₂O→Zn(NH3)₄(OH)₂+H₂O

preferably, the filtrate of the S3 step and the mother liquor can be combined for dilution with high-concentration hydroxymethionine of the S1 step.

Preferably, the hydrolysis neutralization reaction is performed in a reaction kettle, the reaction kettle is one of 304, 304L, 316L and a high-pressure reaction kettle made of 316 materials containing zirconium materials, and the pressure in the hydrolysis neutralization reaction process is controlled to be 0.8-1.8 MPa.

Preferably, the ammonia gas discharged after the hydrolysis neutralization reaction is recovered and can be used for the hydrolysis neutralization reaction of the hydroxy methionine of the next batch.

The method uses the commercial-grade hydroxymethionine as a main raw material, and the commercial-grade hydroxymethionine has high mature yield, low contents of inorganic salt and exogenous organic impurities and is the most economic high-purity hydroxymethionine source, so that the method directly uses the commercial-grade hydroxymethionine to synthesize metal chelate and calcium salt, has the advantages of easily available raw materials and low cost, and is beneficial to the wide application of products.

The invention adopts easily separated and recyclable ammonia as alkali for hydrolyzing the hydroxy methionine oligomer to obtain the liquid methionine ammonium salt solution of the monomer containing free ammonia, wherein the oligomer content is lower than 1 percent, the interference of the hydroxy methionine oligomer in a reaction system is effectively reduced, and hydroxy methionine metal chelate or calcium salt obtained by synthesizing the hydroxy methionine with low oligomer and metal salt or calcium salt has the advantages of high product purity, high yield, uniform chromaticity, good fluidity, stable structure and the like.

The ammonia and the crystallization mother liquor in the invention realize cyclic utilization, and almost no three wastes are generated, particularly, the ammonia plays a role of a hydrolytic agent in the hydroxy methionine hydrolytic oligomer, and the excessive free ammonia in the obtained low-oligomer hydroxy methionine ammonium salt solution can produce a soluble complex with metal salt, thereby greatly promoting the chelation reaction process, preventing the phenomenon of entrainment of the metal salt raw material which reacts too slowly and the precipitated product, playing an effective catalytic role, simultaneously being effectively separated from the system, having no alkali salt residue and being beneficial to improving the product quality.

In addition, the reaction system with ammonia can obtain a solid product with more uniform granularity, more consistent color and better dispersity compared with the same conventional system without ammonia, which is obvious on hydroxymethionine chelate complexes of metal ions such as Zn, Cu and the like with ammonia having complexing, dispersing and dissolving-assisting effects and also has similar effects on hydroxymethionine products of metal ions such as Ca and Mg without complexing effects.

The invention uses water as solvent, does not need organic solvent and alcohol raw materials, and has simple process and lower production cost; and is suitable for various hydroxy methionine chelating products, and is beneficial to elastic production.

Drawings

FIG. 1 is a structural formula of the oligomer main component in hydroxymethionine.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely through the following detailed description, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The preparation method of the low-oligomer hydroxymethionine metal chelate of the invention comprises the following steps:

s1, diluting high-concentration hydroxymethionine, adding ammonia, carrying out hydrolysis neutralization reaction for 45-60 min at 160-200 ℃, then cooling to remove ammonia gas to obtain monomer hydroxymethionine ammonium salt reaction liquid, and recovering the removed ammonia gas to be used in the hydrolysis neutralization reaction of the next batch of hydroxymethionine;

s2, adding a metal compound into the reaction liquid obtained by the reaction in the step S1, controlling the temperature to be 70-105 ℃, reacting for 90-150 min, stirring and naturally cooling to obtain a hydroxymethionine metal chelate suspension, wherein in the step, the adding amount of the metal compound is such that the molar ratio of metal ions to hydroxymethionine is 1: 1.9-2.1, wherein the molar ratio of the metal ions to the free ammonia in the reaction system is 1: 4-6, and if the free ammonia in the reaction system is 4 times lower than the metal ions, ammonia water or ammonia gas is added according to the required amount to complement;

s3, carrying out suction filtration on the hydroxymethionine metal chelate suspension to obtain a solid and a mother solution, washing the solid with distilled water, combining the washed filtrate with the mother solution, and drying the washed solid to obtain a hydroxymethionine metal chelate product.

The hydroxymethionine metal chelate compound of the present invention is one of zinc hydroxymethionine chelate, copper hydroxymethionine chelate and calcium hydroxymethionine, the metal compound that reacts with the monomeric hydroxymethionine ammonium salt is one of oxides or hydroxides of zinc, copper, magnesium and calcium, and zinc oxide, copper oxide, magnesium oxide and calcium oxide are used for illustration in the present invention. The high-concentration hydroxymethionine used in the invention is 88 wt% of commercial-grade hydroxymethionine or a concentrated solution of hydroxymethionine with the concentration of 88-100 wt%, wherein the ammonium sulfate is less than 0.6%, and experimental operation is described below by taking commercial-grade hydroxymethionine with the concentration of 88 wt% as an example. In the present invention, the ammonia that is subjected to the hydrolysis neutralization reaction with hydroxymethionine is any one or more of liquid ammonia, concentrated ammonia (20-30 w%) or ammonia, and the following examples are exemplified by ammonia and ammonia with a concentration of 30 w%. The hydrolysis neutralization reaction is carried out in a reaction kettle, wherein the reaction kettle is one of 304, 304L, 316L and a high-pressure reaction kettle made of 316 materials containing zirconium materials, the pressure of the hydrolysis neutralization reaction needs to be controlled to be 0.8-1.8 MPa, and the experimental operation is described in the following embodiment in which the pressure of the high-pressure reaction kettle made of 316 materials is controlled to be 1.2 MPa.

FIG. 1 is a structural formula of the oligomer main component in hydroxymethionine.

The operation of the low-oligomer hydroxymethionine hydrolysis experiment of the present invention is as follows:

weighing a certain amount of 88 w% of hydroxy Methionine (MHA) with a commercial grade content, mixing the hydroxy Methionine (MHA) with a certain proportion of ammonia, diluting the mixture with water until the concentration of the hydroxy methionine is 20-60%, hydrolyzing the mixture for 30-60 min at different temperatures within 120-200 ℃, and detecting the oligomer content in the MHA before and after neutralization and hydrolysis by using high performance liquid chromatography. Examples 1 to 12 low-oligomer hydroxymethionine hydrolysis experiments were performed according to the above method and the data in table 1, and the specific process conditions and experimental results of each example are shown in table 1:

TABLE 1

The ammonia addition ratio, i.e., the molar ratio of ammonia to hydroxymethionine charged, is shown in Table 1. The experimental result data of the examples 1 to 12 show that the oligomer content in the neutralized and hydrolyzed MHA has a certain relation with the ammonia addition ratio, the MHA dilution concentration, the hydrolysis temperature and the hydrolysis time during hydrolysis, the preferable hydrolysis condition is that the ammonia addition ratio is 4 to 10, the MHA dilution concentration is lower than 50%, the hydrolysis temperature is 160 to 200 ℃, and the hydrolysis time is 45 to 60 min.

On the basis of the embodiments 1-12, the invention carries out the preparation of the low-oligomer hydroxymethionine metal chelate, and the specific preparation method is as follows:

example 13

Respectively weighing 256.8g of commercial grade 88 w% hydroxymethionine and 510g of ammonia water (with the concentration of 30 wt%), mixing the obtained mixed feed liquid into a 1L high-pressure kettle (316 material), sealing the high-pressure kettle, boosting the pressure to 1.2MPa, carrying out hydrolysis neutralization reaction at 170 ℃ for 45min, stopping heating after the reaction is finished, cooling to 40-60 ℃, cooling to about 45 ℃ in the embodiment, opening an exhaust valve, discharging redundant ammonia gas along with pressure gas into a recovery bottle with condensation for recovery, and using the recovered ammonia gas in the next batch of hydroxymethionine hydrolysis neutralization reaction. And opening the kettle for sampling to obtain reaction feed liquid, wherein the reaction feed liquid contains monomer hydroxy methionine ammonium salt, and the mass percent of hydroxy methionine oligomer is detected to be 0.66%.

658g of the above reaction solution was weighed and transferred into a 1L four-neck flask with a stirrer, sampling was performed to detect that the free ammonia was 10.24%, 61g of zinc oxide (ammonia: zinc oxide: 5.28:1) was transferred into the four-neck flask, stirring was started, the temperature was controlled at 70 ℃ for reaction for 90min, and 30min was followed by adding a little vacuum to accelerate ammonia removal. And stopping heating after the reaction time is up, stirring and naturally cooling, and gradually precipitating a large amount of white crystals from a brownish clear system. And (3) cooling to 15-25 ℃, cooling to about 20 ℃ in the embodiment, performing suction filtration to obtain a solid and a mother solution, washing the solid with a small amount of distilled water, and mixing the washed filtrate and the mother solution to obtain 468.3 g. Drying the washed solid to obtain 268.3g of uniform white powdery solid, and detecting the content of hydroxymethionine chelated zinc: 99.5%, single yield in terms of zinc: 98.55%, yield based on hydroxymethionine: 97.68 percent.

Comparative example 1

Mixing 256.8g of commercial grade 88 w% hydroxy methionine with 510g of water, transferring the mixture into a 1L four-neck flask with stirring, uniformly stirring, transferring 61g of zinc oxide into the four-neck flask, controlling the temperature to be 70 ℃ to react for 90min, stopping heating after the reaction time, stirring and naturally cooling, and gradually precipitating a large amount of white crystals from a brownish clear system. And cooling to 15-25 ℃, cooling to about 20 ℃ in the embodiment, performing suction filtration to obtain a solid and a mother solution, washing the solid with a small amount of distilled water, and mixing the washed filtrate and the mother solution to obtain 497.5 g. Drying the washed solid to obtain 261.7g of white powdery solid, and analyzing the content of hydroxymethionine chelated zinc: 99.2%, single yield in terms of zinc: 96.55%, yield based on hydroxymethionine: 94.68 percent.

Example 14

Weighing 257g of commercial-grade hydroxy methionine with the content of 88 wt% and 510g of ammonia water (with the concentration of 30 wt%) respectively, mixing the obtained mixed feed liquid into a 1L high-pressure kettle (316 material), sealing the high-pressure kettle, boosting the pressure to 1.2MPa, and carrying out hydrolysis neutralization reaction for 60min at the temperature of 160 ℃; and stopping heating after the reaction is finished, cooling to 40-60 ℃, cooling to about 50 ℃ in the embodiment, opening an exhaust valve, discharging redundant ammonia gas to a recovery bottle with condensation for recovery, opening the kettle for sampling to obtain reaction feed liquid, wherein the reaction feed liquid contains monomer hydroxy methionine ammonium salt, and detecting the content of hydroxy methionine oligomer without detection.

692.1g of the reaction liquid is transferred into a 1L four-mouth flask with stirring, sampling is carried out to detect that the free ammonia is 9.88 w%, 61g of zinc oxide (ammonia: zinc oxide is 5.36:1) is added, stirring is started, the temperature is controlled at 105 ℃ for reaction for 30min, in order to accelerate ammonia gas removal, a little vacuum is added after 30min, the temperature is controlled at 85 ℃, deamination is continued for 60min, heating is stopped after the reaction time is up, stirring and natural cooling are carried out, and a large amount of white crystals are gradually separated out through brownish clarification of the system. And cooling to 15-25 ℃, cooling to about 20 ℃ in the embodiment, performing suction filtration to obtain a solid and a mother liquor, washing the solid with a small amount of distilled water, and combining the washed filtrate and the mother liquor to obtain 367.4g of combined mother liquor. The washed solid was dried to obtain 266.6g of white powdery solid, and the content of hydroxymethionine chelated zinc was analyzed: 99.7%, single yield in terms of zinc: 97.92%, yield based on hydroxymethionine: 96.29 percent.

Comparative example 2

Weighing 257g of commercial-grade hydroxy methionine with the content of 88 wt% and 510g of water respectively, mixing 767g of the feed liquid, adding into a 1L four-neck flask with stirring, adding 61g of zinc oxide, starting stirring, controlling the temperature to be 105 ℃ for reaction for 30min, controlling the temperature to be 85 ℃ after 30min for accelerating ammonia removal, continuing the reaction for 60min, stopping heating after the reaction time is up, stirring and naturally cooling, and gradually precipitating a large amount of white crystals from brown clarification. And (3) cooling to 15-25 ℃, cooling to about 20 ℃ in the embodiment, performing suction filtration to obtain a solid and a mother solution, washing the solid with a small amount of distilled water, and mixing the washed filtrate and the mother solution to obtain 347.6 g. The solid was dried to give 266.6g of a white-like powdery solid with a small amount of brown small particles, and analyzed for the hydroxymethionine chelated zinc content: 99.1%, single yield in terms of zinc: 96.27%, yield based on hydroxymethionine: 96.05 percent.

Example 15

Respectively weighing 245.6g of commercial-grade hydroxy methionine with the content of 88 wt% and 295.4g of combined mother liquor in example 14, mixing, detecting the concentration of the hydroxy methionine in the diluted mixed feed liquid to be 40 wt%, transferring the feed liquid into a 1L high-pressure autoclave (316 material), sealing the high-pressure autoclave, boosting the pressure to 1.2MPa, introducing 9mol of ammonia gas, and hydrolyzing and neutralizing at 170 ℃ for 45 min; and stopping heating after the reaction is finished, cooling to 40-60 ℃, cooling to about 45 ℃ in the embodiment, opening an exhaust valve, discharging redundant ammonia gas to a recovery bottle with condensation for recovery, opening a kettle for sampling to obtain reaction feed liquid, wherein the reaction feed liquid contains monomer hydroxy methionine ammonium salt, and the mass percent of hydroxy methionine oligomer is detected to be 0.78%.

Transferring 458.4g of the reaction solution into a 1L four-neck flask with a stirrer, sampling to detect that the free ammonia is 12.25%, adding 61g of zinc oxide (ammonia: zinc oxide is 4.4:1), starting the stirrer, controlling the temperature to be 85 ℃ for reaction for 120min, adding a little vacuum after 30min to accelerate the removal of ammonia gas, controlling the temperature to be 85 ℃, continuing deamination for 60min, stopping heating after the reaction time is up, stirring and naturally cooling, and gradually precipitating a large amount of white crystals from a brownish clarification system. And (3) cooling to 15-25 ℃, cooling to about 20 ℃ in the embodiment, performing suction filtration to obtain a solid and a mother liquor, washing the solid with a small amount of distilled water, and combining the washed filtrate and the mother liquor to obtain 312.7g of combined mother liquor. And drying the washed solid to obtain 270.1g of white powdery solid, and analyzing the content of hydroxymethionine chelated zinc: 99.5%, yield in terms of zinc: 99.2%, single yield based on hydroxymethionine: 97.55 percent.

The data of the experimental results of examples 13 to 15 and comparative examples 1 and 2 were counted, and the results are shown in Table 2:

TABLE 2

The data in table 2 show that the low-oligomer zinc hydroxymethionine chelate prepared by the preparation method of the invention has higher content and yield than the common commercial-grade zinc hydroxymethionine chelate, and the appearance of the prepared zinc hydroxymethionine chelate product presents more uniform white due to the fact that most oligomers are converted into monomers (the oligomer content is lower than 1 percent); the product prepared by directly mixing common commercial-grade hydroxy methionine and zinc oxide is white-like powder, part of the product has a small amount of brown small particles, and mainly the color substance brought by oligomer is not eliminated, so that the appearance of the product influenced by the molecular level uniformity is reflected.

Example 16

Mixing 255.8g of commercial grade 88 w% hydroxy methionine with 510g of ammonia water (30 wt% concentration), transferring the obtained mixed feed liquid into a 1L high-pressure kettle (316 material), sealing the high-pressure kettle, boosting the pressure to 1.2MPa, and hydrolyzing and neutralizing for 45min at 170 ℃; and stopping heating after the reaction is finished, cooling to 40-60 ℃, cooling to about 45 ℃ in the embodiment, opening an exhaust valve, discharging redundant ammonia gas along with pressure gas into a recovery bottle with condensation for recovery, opening a kettle for sampling to obtain reaction feed liquid, wherein the reaction feed liquid contains monomer hydroxy methionine ammonium salt, and the mass percent of hydroxy methionine oligomer is detected to be 0.50%.

643g of the reaction liquid is transferred into a 1L four-mouth flask with stirring, sampling is carried out to detect that free ammonia is 11.14%, 59.6g of copper oxide powder (ammonia: copper oxide is 5.63:1) is transferred into the four-mouth flask, 72g of ammonium carbonate is supplemented, stirring is started, the temperature is controlled at 90 ℃ for reaction for 150min, in order to accelerate ammonia gas removal, a little vacuum is added after 30min, heating is stopped after reaction time is up, stirring and natural cooling are carried out, suspension containing a large amount of bright blue crystals is obtained, the temperature is reduced to 15-25 ℃, the temperature in the embodiment is reduced to about 20 ℃, solid and mother liquid are obtained through suction filtration, the solid is washed with a small amount of distilled water, filtrate obtained through washing is combined with the mother liquid, and 468.3g of combined mother liquid is obtained. The solid was dried to obtain 281.3g of a blue powdery solid, and the hydroxymethionine chelated copper content was analyzed as follows: 99.5%, single yield in terms of copper: 99.11%, single yield based on hydroxymethionine: 97.23 percent.

Comparative example 3

Mixing 255.8g of commercial grade 88 w% hydroxy methionine with 510g of water, transferring 765.8g of mixed material liquid into a 1L four-neck flask with a stirrer, transferring 59.6g of copper oxide powder into the four-neck flask, starting stirring, controlling the temperature to 90 ℃ for reaction for 150min, stopping heating after the reaction time, stirring and naturally cooling to obtain a suspension containing a large amount of bright blue crystals. And cooling to 15-25 ℃, cooling to about 20 ℃ in the embodiment, performing suction filtration to obtain a solid and a mother liquor, washing the solid with a small amount of distilled water, and combining the washed filtrate and the mother liquor to obtain 468.3g of combined mother liquor. The washed solid was dried to obtain 278.8g of a blue powdery solid, and the hydroxymethionine chelated copper content was analyzed: 99.1%, single yield in terms of copper: 98.33%, single yield based on hydroxymethionine: 97.10 percent.

Example 17

Mixing 250g of commercial-grade hydroxy methionine with the content of 88 wt% with 300g of water to dilute the concentration of the hydroxy methionine to 40 wt%, transferring the mixed feed liquid into a 1L high-pressure kettle (316 material), sealing the high-pressure kettle, boosting the pressure to 1.2MPa, introducing 9mol of ammonia gas, and hydrolyzing and neutralizing for 45min at the temperature of 170 ℃; and stopping heating after the reaction is finished, cooling to 40-60 ℃, cooling to about 45 ℃ in the embodiment, opening an exhaust valve, discharging redundant ammonia gas along with pressure gas into a recovery bottle with condensation for recovery, opening a kettle for sampling to obtain reaction feed liquid, wherein the reaction feed liquid contains monomer hydroxy methionine ammonium salt, and detecting the content of the hydroxy methionine oligomer in the reaction feed liquid by mass percent of 0.72%.

450g of the above feed solution was transferred to a 1L four-necked flask with a stirrer, 10.14% of free ammonia was detected by sampling, 42g of calcium oxide powder (ammonia: calcium oxide: 3.58:1) was digested with a small amount of water and transferred to the four-necked flask, and ammonia water was added to the four-necked flask at a concentration of 30 w% so that ammonia: and (2) starting stirring, controlling the temperature to be 90 ℃ for reaction for 150min, adding a little vacuum after 30min in order to accelerate ammonia removal, stopping heating after the reaction time is up, stirring and naturally cooling to obtain a suspension containing white solids, cooling to 10-25 ℃, cooling to about 20 ℃ in the embodiment, carrying out suction filtration to obtain solids and mother liquor, washing the solids with a small amount of distilled water, and combining the washed filtrate and the mother liquor to obtain 162.3g of combined mother liquor. Drying the washed solid to obtain 222.3g of white powdery solid, and analyzing the content of the hydroxy methionine calcium: 99.4%, single yield in calcium: 87.69%, yield based on hydroxymethionine: 86.29 percent.

Comparative example 4

Mixing 250g of commercial-grade hydroxy methionine with the content of 88 wt% with 300g of water to dilute the hydroxy methionine to the concentration of 40 wt%, transferring 550g of mixed material liquid into a 1L four-neck flask with stirring, digesting 42g of calcium oxide powder with a small amount of water, transferring into the four-neck flask, starting stirring, controlling the temperature to 90 ℃ for reaction for 150min, stopping heating after the reaction time is up, stirring and naturally cooling to obtain suspension containing white solid, cooling to 10-25 ℃, cooling to about 20 ℃ in the embodiment, performing suction filtration to obtain solid and mother liquid, washing the solid with a small amount of distilled water, and mixing the washed filtrate with the mother liquid to obtain 148.4g of combined mother liquid. Drying the washed solid to obtain 217.7g of white powdery solid, and analyzing the content of the hydroxy methionine calcium: 99.6%, single yield in calcium: 85.88 w%, yield 86.22% calculated as hydroxymethionine.

The data of the experimental results of examples 16 and 17 and comparative examples 3 and 4 were subjected to statistics, and the results are shown in table 3:

TABLE 3

The data in table 3 show that the chelated copper or calcium salt prepared by hydrolyzing the hydroxy methionine reduced oligomer is higher than the product prepared by common high-oligomer hydroxy methionine in the aspects of appearance color and luster and uniformity of the product, the product yield is 1-2% higher than the product prepared by common high-oligomer hydroxy methionine in terms of metal ions, the implementation effect is obviously improved, and the appearance states of the product prepared by the method, such as color, particle size and the like, are obviously better than those of the comparative example.

Example 17

Mixing 250g of commercial-grade hydroxy methionine with the content of 88 wt% with 300g of water to dilute the concentration of the hydroxy methionine to 40 wt%, transferring the mixed feed liquid into a 1L high-pressure kettle (316 material), sealing the high-pressure kettle, boosting the pressure to 1.2MPa, introducing 9mol of ammonia gas, and hydrolyzing and neutralizing for 45min at the temperature of 170 ℃; and stopping heating after the reaction is finished, cooling to 40-60 ℃, cooling to about 45 ℃ in the embodiment, opening an exhaust valve, discharging redundant ammonia gas along with pressure gas into a recovery bottle with condensation for recovery, opening a kettle for sampling to obtain reaction feed liquid, wherein the reaction feed liquid contains monomer hydroxy methionine ammonium salt, and detecting the content of the hydroxy methionine oligomer in the reaction feed liquid by mass percent of 0.65%.

446g of the above stock solution was transferred to a 1L four-necked flask with a stirrer, a free ammonia content was measured by sampling and was 11.34%, 30g of magnesium oxide powder (ammonia: magnesium oxide: 3.97:1) was digested with a small amount of water and transferred to the four-necked flask, and ammonia water was added to the four-necked flask at a concentration of 30 w% so that ammonia: and (2) starting stirring, controlling the temperature to be 90 ℃ for reaction for 150min to accelerate ammonia gas removal, adding a little vacuum after 30min, stopping heating after the reaction time is up, stirring and naturally cooling to obtain a suspension containing white solids, cooling to 25 ℃, cooling to about 20 ℃ in the embodiment, performing suction filtration to obtain solids and mother liquor, washing the solids with a little distilled water, and mixing the washed filtrate with the mother liquor to obtain 132.3g of combined mother liquor. The washed solid was dried to obtain 165.3g of a white powdery solid, magnesium content: 9.89%, analyzing the content of magnesium hydroxymethionine: 99.4%, single yield in terms of magnesium: 90.83%, yield based on hydroxymethionine: 92.61 percent.

Comparative example 5 (repeat example 13 with removal of ammonia)

Mixing 250g of commercial-grade hydroxy methionine with the content of 88 wt% with 300g of water to dilute the concentration of the hydroxy methionine to 40 wt%, transferring the mixed feed liquid into a 1L high-pressure kettle (316 material), sealing the high-pressure kettle, boosting the pressure to 1.2MPa, introducing 9mol of ammonia gas, and hydrolyzing and neutralizing for 45min at the temperature of 170 ℃; and stopping heating after the reaction is finished, cooling to about 45 ℃, opening an exhaust valve, discharging redundant ammonia gas along with pressure gas into a recovery bottle with condensation for recovery, opening the kettle for sampling to obtain monomer hydroxy methionine ammonium salt feed liquid, and detecting that the content of hydroxy methionine oligomer is 0.66% by mass and the content of free ammonia is 10.14%.

Transferring 450g of the feed liquid into a 1L single-neck flask, removing ammonia in a system by using a rotary evaporator under reduced pressure at 45 ℃, removing the ammonia until the system is basically free of ammonia odor, then supplementing the system with desalted water until the system is 450g, detecting that the free ammonia is 0.86%, transferring the deaminated system into the 1L single-neck flask, digesting 42g of calcium oxide powder (ammonia: calcium oxide: 0.30:1) with a small amount of water, transferring the calcium oxide powder into a four-neck flask, starting stirring, controlling the temperature to 90 ℃ for reaction for 150min, stopping heating after the reaction time is up, stirring, naturally cooling to obtain a suspension containing white solids, cooling to 10-25 ℃, cooling to about 20 ℃ in the embodiment, performing suction filtration to obtain solids and mother liquid, washing the solids with a small amount of distilled water, and combining the washed filtrate with the mother liquid to obtain 171.3g of combined mother liquid. And drying the washed solid to obtain 221.7g of a white powdery solid, wherein part of the white powdery solid is agglomerated, some larger agglomerates are easy to disperse, and the smaller agglomerates are harder and difficult to disperse, and analyzing the content of the hydroxy methionine: 99.1%, single yield in calcium: 87.71%, yield based on hydroxymethionine: 85.58 percent.

From the results of comparative example 5 and example 13, it can be determined that ammonia in the reaction system not only helps to keep the reaction to proceed with the effective reaction of the monomeric hydroxy methionine and the easily soluble metal ammonia complex to obtain the hydroxy methionine salt product with high quality, but also the free ammonia has a significant beneficial effect on the system and/or the dispersion of the product, and the results of the examples and comparative examples in table 2 and table 3 obviously support the conclusion.

Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims. The techniques, shapes, and configurations not described in detail in the present invention are all known techniques.