Production process and production system of methionine and methionine hydroxyl analogue

A technology of methionine hydroxyl group and production process, which is applied in the field of feed preparation preparation, can solve the problems of difficult recovery of MET, long-term uniformity of high-concentration MHA, stability, fluidity, and impact on separation and recovery, so as to avoid impurities such as iminodinitrile , The reaction process is energy-saving and efficient, and the effect of increasing the reaction temperature

CN113336684APending Publication Date: 2021-09-03LUFENG TIANBAO PHOSPHORUS CHEM CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2021-09-03

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Abstract

The invention belongs to the field of preparation of feed preparations, and particularly relates to a production process and a production system of methionine and methionine hydroxyl analogues. The process compriseeds the following steps: (1) carrying out rapid unsaturated ammoniation on cyanohydrin and ammonia water to prepare a 2-amino-4-methylthio butyronitrile crude reaction solution; (2) reacting the aminobutyronitrile crude reaction liquid with a solid catalyst to obtain methionine hydrolysate; (3) filtering, deaminizing, concentrating and separating the methionine hydrolysate to obtain methionine solid and crystallization mother liquor, the solid catalyst being a cerium oxide catalyst or a solid acid catalyst. According to the production process provided by the invention, an independent cyanohydrin rapid unsaturated ammoniation strategy is adopted, and interference of materials, catalysts and reaction products in other steps on the cyanohydrin ammoniation step is avoided as much as possible, so that adverse side reactions such as cyanohydrin decomposition and excessive ammoniation are avoided.
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Description

technical field

[0001] The invention belongs to the field of feed preparation preparation, and in particular relates to a production process and production system of methionine and methionine hydroxyl analogs. Background technique

[0002] Methionine (2-amino-4-methylthiobutyric acid, MET) and methionine hydroxyl analogs (2-hydroxy-4-methylthiobutyric acid, MHA) have been widely used as animal feed additives to supplement the necessary methionine for animals. use. However, in the current technology, the two often need to be produced separately due to the difference in the post-process of the intermediate 3-methylthiopropanal or up to 2-hydroxy-4-methylthiobutyronitrile (cyanohydrin), and also consume a large amount of acid Alkali generates unnecessary low-value by-product salts, and it is difficult to completely separate the product from the inorganic salts. Chinese patent CN109467526A discloses a method for producing methionine and / or methionine hydroxy analogs by 3-methy...

Examples

Embodiment 1

[0037] 364g cyanohydrin (72wt%, 2mol) and 1214g ammoniacal liquor (28wt%, 20mol) are sent into tubular reactor, at 65 ℃, react 10min under 0.8MPa condition, obtain 2-amino-4-methylthiobutyronitrile crude Reaction solution 1388g (the total concentration of aminobutyronitrile and cyanohydrin is about 18.87wt%, wherein 2-amino-4-methylthiobutyronitrile molar ratio is 88%, cyanohydrin molar ratio is 12%, iminoethanedinitrile is not detected out).

[0038] The above-mentioned 2-amino-4-methylthiobutyronitrile (aminobutyronitrile) crude reaction solution was transferred to a 3L reaction kettle, 681g of cerium oxide (2.6 times) was added, stirred and reacted at 100°C for 2h, and the total amount of cyanohydrin and aminobutyronitrile was analyzed. The residue is less than 0.1wt%. Solid-liquid separation and deamination are carried out while hot to obtain cerium dioxide and methionine hydrolyzate (MHA:MET=0.14, amide 0.15wt%). The methionine hydrolyzate is concentrated to obtain methio...

Embodiment 2

[0039] Embodiment 2 (reuse)

[0040] Mix 291.1g of cyanohydrin (90wt%, 2mol) and 637.5g of ammonia water (32%, 12mol) with a static mixer, then send them into a tubular reactor, and react at 75°C and 0.8MPa for 6min to obtain 2-amino- 4-methylthiobutyronitrile crude reaction solution 823.3g (the total concentration of aminobutyronitrile and cyanohydrin is about 31.83wt%, wherein 2-amino-4-methylthiobutyronitrile molar ratio is 87%, cyanohydrin molar ratio is 13% %, iminoethanedinitrile was not detected).

[0041] The above-mentioned 2-amino-4-methylthiobutyronitrile (aminobutyronitrile) crude reaction solution was transferred to a 3L reactor, and 472.3g of the crystallization mother liquor from Example 1 (MET: 3.19wt%, MHA: 7.63wt%, Amide: 0.26wt%) and 681g solid catalyst cerium oxide (2.6 times), 100 ° C stirring reaction for 2h, analysis of cyanohydrin and aminobutyronitrile total residue is less than 0.1wt%, while hot solid-liquid separation, deamination were obtained two ...

Embodiment 3

[0042] Embodiment 3 (reuse)

[0043] The same as in Example 2, after the ammonification of cyanohydrin, the crystallization mother liquor of Example 2 was reused, and reacted with cerium dioxide to obtain a methionine hydrolyzate (MHA:MET=0.41, amide 0.52wt%), and the methionine hydrolyzate was concentrated, separated, Drying and other steps Solid methionine 247.2g and crystallization mother liquor 577.3g (MET: 4.62wt%, MHA: 19.76wt%, amide: 0.71wt%).