CN114685603A

CN114685603A - Method for preparing methionine

Info

Publication number: CN114685603A
Application number: CN202210491686.3A
Authority: CN
Inventors: 刘帮林; 曹华伟; 张�成; 武永堂; 陆荣; 王晓庆; 吴志强; 周蕾; 屈晓磊; 王家喜; 赵二宝; 刘波; 柳亚玲; 赵丹丹; 贾亮
Original assignee: Ningxia Unisplendour Tianhua Methionine Co Ltd
Current assignee: Ningxia Unisplendour Tianhua Methionine Co Ltd
Priority date: 2022-05-07
Filing date: 2022-05-07
Publication date: 2022-07-01

Abstract

The invention relates to the technical field of chemical industry, in particular to a preparation method of methionine, which is characterized in that in the process of preparing methionine by using hydantoin as a reaction raw material, conditions such as reaction temperature, reaction time, alkali concentration, proportion of each reactant, reaction pressure and the like are controlled, so that a primary reaction system is controlled to react to a system taking hydantoin derivatives as a large number of products, a target molecule is obtained by utilizing the characteristic of low solubility of 2Met through a filtering mode, meanwhile, for a methionine production system, no additional component is added in a mother liquor generated in the filtering process, a secondary reaction system can be formed after the mother liquor reacts for a certain time under a certain reaction pressure and reaction temperature, and the secondary reaction system is the methionine production system. The method has the advantages of simple operation and no need of additional post-treatment, and can greatly reduce the energy consumption in the 2Met synthesis process.

Description

Preparation method of methionyl methionine

Technical Field

The invention relates to the technical field of chemical industry, in particular to a preparation method of methionine.

Background

Methionine (also called Methionine), an essential amino acid in all metazoan. Together with cysteine, methionine is one of two sulfur-containing proteinogenic amino acids. The amino acid is the only essential amino acid containing sulfur for human, and has two types of L type and D type, which are closely related to the metabolism of various sulfur-containing compounds (such as protein) in organisms and are the main sources of active methyl and sulfur in the bodies. Methionyl methionine (herein substituted with 2 Met) is involved in biochemical reactions after cleavage of a mobile entity by dipeptidases into 2 methionine molecules, and has unique biological value due to the low solubility characteristic of 2 Met. The application of 2Met to various livestock and aquatic products is researched by a plurality of literatures, the application has important values in the aspects of improving the production function, improving the utilization rate of non-limiting amino acid, reducing the feed coefficient and reducing environmental pollution, and the application of enveloped methionine which is a similar physical protection means is not needed particularly when the feed is used for water injection.

There are a number of intermediate derivatives in the hydrolytic preparation of methionine using 5- (β -methylthioethyl) hydantoin (hydantoin is substituted for hydantoin in this application), including 2 Met. 2Met, namely, the amino group of one methionine and the carboxyl group of another methionine are dehydrated into amide, two methionine are connected by amide bond to form dipeptide, and the solubility of methionine is hundreds times of that of 2 Met.

Four kinds of isomers exist in artificially synthesized 2Met, including D-methylinyl-D-methylionine, D-methylinyl-L-methylionine, L-methylinyl-D-methylionine and L-methylinyl-L-methylionine, and 2Met represents the four isomers without specific description. Common chemical synthesis and enzymatic synthesis can be used for synthesizing 2Met, and in Chinese patent application with publication numbers CN109234343A and CN102429109A, papain is used for processing hydrochloride of L-methionine ethyl ester to obtain methionine dipeptide. In general chemical synthesis, activation is required because of the chemical inertness of carboxylic acid to amide, which means that cumbersome pre-and post-treatments or harsh reaction conditions are required during the synthesis of 2Met using methionine. Therefore, the prior art is still lacking a method for producing methionyl methionine which is simple in pretreatment and post-treatment.

Disclosure of Invention

In order to solve the above technical problems, an object of the present invention is to provide a method for producing methionyl methionine, wherein the methionyl methionine produced by the method has high purity, a simple reaction process, and a significantly reduced energy consumption in the synthesis process.

In order to achieve the technical effect, the invention adopts the following technical scheme:

a process for preparing methionine includes such steps as mixing hydantoin-containing raw material with alkali to form a primary reaction system, reacting at a certain reaction pressure and reaction temp for a certain time, cooling, filtering, separating solid methionine, and reacting at a certain reaction pressure and reaction temp for a certain time to obtain filtrate.

Further, the reaction system is acidified by adding an acid, preferably sulfuric acid or carbon dioxide, to the secondary reaction system to perform a secondary reaction for extracting methionine.

Further, the alkali is any one or more of hydroxide, carbonate, bicarbonate and methionine salt of alkali metal, and the type of the alkali is selected according to the type of acid added in the methionine extraction process.

Further, the molar ratio of the base to the hydantoin and the hydantoin derivative is 0.1-1: 1, and preferably 0.1-0.5: 1.

Further, the molar ratio of the number of moles of methionine to the number of moles of hydantoin is 0 to 2:1, more preferably 0 to 1:1,

preferably, when the acid used for acidifying the secondary reaction system is carbon dioxide, the alkali is mother liquor generated after methionine is filtered from hydrolysate acidified by carbon dioxide or regenerated liquor generated after high-temperature regeneration of the mother liquor or a mixture of any one or more of alkaline hydrolysate generated after hydantoin is hydrolyzed by potassium carbonate, potassium bicarbonate, potassium hydroxide and alkaline potassium.

Preferably, when the acid used in the secondary reaction process is sulfuric acid, the base is any one or more of sodium carbonate, sodium bicarbonate, sodium hydroxide or a mixture of alkaline hydrolysates produced after hydrolysis of hydantoin with alkaline sodium.

Further, the time period is 10-600 min, preferably 10-50 min, more preferably 30-50 min, in the specific reaction process, the time period is determined by measuring the molar ratio of methionine to hydantoin in the primary reaction system, and when the molar ratio of methionine to hydantoin is not less than 5, the reaction can be stopped.

Further, the reaction pressure is 2-15 bar.

Further, the reaction temperature is 90-180 ℃.

Further, in the temperature reduction and filtration step, the temperature of the reaction liquid is controlled to be reduced to 30-70 ℃, preferably 40-50 ℃, and in the specific implementation, heat transfer or mass transfer and heat transfer can be used for reducing the temperature, and solids are filtered and separated in the temperature range.

And further, leaching the obtained solid with water after filtering and separating the solid, drying to obtain 2Met, combining leacheate generated in the leaching process into the filtrate, and preparing a second reaction system together. The mixed liquor of the filtrate and the leacheate produced in the filtering process mainly contains alkali metals, methionine, hydantoin and other derivatives of hydantoin in solute, and can still continuously prepare methionine under the condition of preparing methionine by hydrolyzing the hydantoin, because the concentration of the methionine derivative is lower and the hydrolysis is influenced by carbon dioxide and ammonia, the mixed liquor is preferably returned to the step of deamination of the hydantoin.

Compared with the prior art, the invention has the beneficial effects that:

according to the preparation method of the methionine provided by the invention, in the process of preparing the methionine by taking hydantoin as a reaction raw material, the conditions of reaction temperature, reaction time, alkali concentration, the proportion of each reactant, reaction pressure and the like are controlled, so that the reaction of the primary reaction system is controlled to be a mixed system which takes hydantoin derivatives as a large amount of products and takes the methionine as a small amount of products, the target molecule is obtained by utilizing the characteristic of low solubility of 2Met through a filtering mode, meanwhile, for the methionine production system, no additional component is added in the mother liquor generated in the filtering process, a secondary reaction system can be formed for producing the methionine under the original production process condition, the preparation method has the advantages of simple operation and no need of additional post-treatment, and meanwhile, the energy consumption and the synthesis cost in the 2Met synthesis process can be greatly reduced.

Detailed Description

The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby. It is to be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials are commercially available unless otherwise specified.

Example 1

1000g of 30 wt% hydantoin solution, 28g of sodium hydroxide and 30g of desalted water are uniformly mixed in a high-pressure reaction kettle, a heating jacket is heated to 90 ℃ in advance, then the mixture is installed in the reaction kettle, and the reaction is carried out for 30 min. After the reaction is finished, the temperature is reduced to 50 ℃, then the reaction product is filtered, and the desalted water washed filter cake is dried to obtain 84.5g of 2Met yellow powder with the purity of more than 99 wt%, and the yield is 35 wt%.

Example 2

Reaction raw materials: the hydantoin hydrolysate contains 20 wt% of methionine and 6 wt% of alkaline sodium.

Mixing 268g of hydantoin hydrolysate with 790g of 30 wt% hydantoin solution uniformly, heating the heating jacket to 140 ℃ in advance, then installing the heating jacket in a reaction kettle, and timing for 30 min. After the reaction is finished, the temperature is reduced to 50 ℃, then the mixture is filtered, and the desalted water washed filter cake is dried to obtain 67g of 2Met yellow powder with the purity of more than 99 wt%, and the yield is 28 wt%

Example 3

1000g of 30 wt% hydantoin solution, 28g of sodium hydroxide and 30g of desalted water are uniformly mixed in a high-pressure reaction kettle, a heating sleeve is heated to 130 ℃ in advance, and then the mixture is installed in the reaction kettle to start timing for 30 min. After the reaction is finished, the temperature is reduced to 50 ℃, then the reaction product is filtered, and after a desalted water washing filter cake is dried, 96.6g of 2Met yellow powder with the purity of more than 99 wt% is obtained, and the yield is 40 wt%.

Example 4

1000g of 30 wt% hydantoin solution, 29g of potassium hydroxide and 75g of desalted water are uniformly mixed in a high-pressure reaction kettle, a heating jacket is heated to 160 ℃ in advance, and then the reaction kettle is arranged for timing for 30 min. After the reaction is finished, the temperature is reduced to 70 ℃, then the mixture is filtered, desalted water is used for washing a filter cake, and the filter cake is dried to obtain 104g of 2Met yellow powder with the purity of more than 99 wt%, wherein the yield is 43 wt%.

Example 5

Reaction raw materials: the hydrolysis liquid of hydantoin contains 15 wt% of methionine and 11 wt% of alkaline potassium.

Mixing hydantoin hydrolysate 180g and hydantoin solution 895g with concentration of 30 wt%, heating the mixture to 160 deg.c in a heating jacket, setting in a reactor and timing for 30 min. After the reaction is finished, the temperature is reduced to 40 ℃, then the mixture is filtered, and the desalted water is used for washing and drying a filter cake to obtain 48.3g of 2Met yellow powder with the purity of more than 99 wt%, and the yield is 20 wt%.

Example 6

1000g of 30 wt% hydantoin solution, 29g of potassium hydroxide and 75g of desalted water are uniformly mixed in a high-pressure reaction kettle, a heating jacket is heated to 180 ℃ in advance, and then the reaction kettle is arranged to start timing for 50 min. After the reaction is finished, the temperature is reduced to 30 ℃, then the mixture is filtered, and the desalted water washing filter cake is dried to obtain 43g of 2Met yellow powder with the purity of more than 99 wt%, and the yield is 18 wt%.

Example 7

The hydrolysis liquid of hydantoin is mother liquid obtained after extracting methionine by carbon dioxide acidification, wherein the methionine content is 3 wt%, and the alkaline potassium content is 12 wt%.

170g of mother liquor and 980g of 30 wt% hydantoin solution are uniformly mixed, a heating jacket is heated to 160 ℃ in advance and then is installed in a reaction kettle, and the time is counted for 30 min. After the reaction is finished, the temperature is reduced to 40 ℃, then the mixture is filtered, and the desalted water is used for washing and drying a filter cake to obtain 79g of 2Met yellow powder with the purity of more than 99 wt%, wherein the yield is 33 wt%.

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.

Claims

1. A method for producing methionine, which is characterized in that: mixing a reaction raw material containing hydantoin with alkali to form a primary reaction system, reacting the primary reaction system for a certain time at a certain reaction pressure and reaction temperature, cooling and filtering reaction liquid, separating out solid methionine, and reacting filtrate generated by filtering for a certain time at a certain reaction pressure and reaction temperature to form a secondary reaction system.

2. The method for producing methionyl methionine according to claim 1, wherein: the alkali is any one or mixture of more of hydroxide, carbonate, bicarbonate and methionine salt of alkali metal.

3. The method for producing methionyl methionine according to claim 2, wherein: and acidifying the reaction system by adding acid into the secondary reaction system to perform secondary reaction for extracting methionine.

4. The process for producing methionyl methionine according to claim 3, wherein: the acid is sulfuric acid or carbon dioxide.

5. The method for producing methionyl methionine according to claim 4, wherein: when the acid is carbon dioxide, the alkali is a mother solution generated after the carbon dioxide acidifies hydrolysate and methionine is filtered, or a regeneration solution generated after the mother solution is regenerated at high temperature, or a mixture of any one or more of potassium carbonate, potassium bicarbonate, potassium hydroxide and alkaline hydrolysate generated after hydantoin is hydrolyzed by alkaline potassium.

6. The method for producing methionyl methionine according to claim 5, wherein: when the acid is sulfuric acid, the alkali is any one or a mixture of more of sodium carbonate, sodium bicarbonate, sodium hydroxide or alkaline hydrolysate generated after hydantoin is hydrolyzed by alkaline sodium.

7. The method for producing methionyl methionine according to claim 1, wherein: the time duration is 30-50 min.

8. The method for producing methionyl methionine according to claim 1, wherein: the reaction temperature is 90-180 ℃.

9. The method for producing methionyl methionine according to claim 1, wherein: and in the temperature reduction and filtration step, the temperature of the reaction liquid is controlled to be reduced to 30-70 ℃, and the solid is filtered and separated in the temperature range.

10. The method for producing methionyl methionine according to claim 5, wherein: and filtering and separating the solid, leaching the obtained solid with water, drying to obtain 2Met, combining leacheate generated in the leaching process into the filtrate, and preparing a second reaction system together.