A clean and continuous process for the preparation of 2-hydroxy-4-methylthiobutyric acid

A technology of methylthiobutyric acid and methylthiobutyronitrile, which is applied in sulfide preparation, organic chemistry and other directions, can solve the problems of underutilization, low atom utilization rate, and high processing cost, and reduce sales and environmental protection pressure. , Simplified emissions and treatment steps, the effect of less ammonia consumption

Active Publication Date: 2019-06-04
SHANDONG XINHECHENG AMINO ACID
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0012] (1) In the hydrolysis process of 2-hydroxy-4-methylthiobutyronitrile, a large amount of inorganic acid will be used. At present, sulfuric acid is mostly used in industrial production, which will produce a large amount of ammonium sulfate. The prior art generally uses this by-product The product is sold as a product after incineration or treatment, and the treatment cost is too high
[0013] (2) The inorganic acid and ammonia are not fully utilized, and the utilization rate of atoms is low

Method used

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  • A clean and continuous process for the preparation of 2-hydroxy-4-methylthiobutyric acid
  • A clean and continuous process for the preparation of 2-hydroxy-4-methylthiobutyric acid
  • A clean and continuous process for the preparation of 2-hydroxy-4-methylthiobutyric acid

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0068] Example 1 A clean method for the continuous preparation of 2-hydroxy-4-methylthiobutyric acid

[0069] Include the following steps:

[0070] (1) Preparation of hydrocyanic acid

[0071] Step a, prepare the mixed gas I containing prussic acid

[0072] According to the Angle method production process, when the device is started for the first time, the filtered air is mixed at 129.10kg / h and natural gas at 8.78kg / h, and then sent to the feed pipe of hydrocyanic acid reactor A, and at the same time, the feed pipe is passed Inject 9.51kg / h of ammonia gas, the mixed gas of the three enters the hydrocyanic acid reactor A, the reaction temperature is controlled at 1100°C, and the reaction results in 8.51% hydrocyanic acid, 6.87% water, 0.34% ammonia gas, and 0.87% carbon monoxide. Oxygen 1.89%, nitrogen 81.03%, hydrogen 0.5% mixed gas I containing hydrocyanic acid.

[0073] Step b, ammonia neutralization

[0074] Mixed gas I containing hydrocyanic acid is sent to ammonia ne...

Embodiment 2

[0092] Example 2 A clean and continuous method for preparing 2-hydroxy-4-methylthiobutyric acid

[0093] Include the following steps:

[0094] (1) Preparation of hydrocyanic acid

[0095] Step a, prepare the mixed gas I containing prussic acid

[0096] According to the Angle method production process, when the device is started for the first time, the filtered air is mixed at 143.21kg / h and natural gas at 9.74kg / h, and then sent to the feed pipe of hydrocyanic acid reactor A, and at the same time, the feed pipe is passed Inject 10.55kg / h of ammonia gas, the mixed gas of the three enters the hydrocyanic acid reactor A, the reaction temperature is controlled at 1050°C, and the reaction results in 8.86% hydrocyanic acid, 6.67% water, 0.44% ammonia gas, and 0.77% carbon monoxide. Oxygen 1.29%, nitrogen 81.47%, hydrogen 0.5% hydrogen cyanide mixed gas I.

[0097] Step b, ammonia neutralization

[0098] Hydrocyanic acid mixed gas I is sent into ammonia neutralization tower B wit...

Embodiment 3

[0116] Example 3 A clean and continuous method for preparing 2-hydroxy-4-methylthiobutyric acid

[0117] Include the following steps:

[0118] (1) Preparation of hydrocyanic acid

[0119] Step a, prepare the mixed gas I containing prussic acid

[0120] According to the Angle method production process, when the device is started for the first time, the filtered air is mixed at 162.08kg / h and natural gas at 11.03kg / h, and then sent to the feed pipe of hydrocyanic acid reactor A, and at the same time, it is fed into the feed pipe 11.94kg / h of ammonia gas, the mixed gas of the three enters the hydrogen cyanide reactor A, the reaction temperature is controlled at 1000°C, and the reaction contains 8.91% hydrogen cyanide, 6.62% water, 0.42% ammonia, 0.66% carbon monoxide, and oxygen 1.31%, nitrogen 81.68%, hydrogen 0.4% hydrocyanic acid mixed gas I.

[0121] Step b, ammonia neutralization

[0122] Hydrocyanic acid mixed gas I is sent into ammonia neutralization tower B with the s...

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PUM

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Abstract

The invention provides a method for clean continuous preparation of 2-hydroxy-4-methylthiobutyric acid. The method comprises preparation of hydrocyanic acid and preparation of 2-hydroxy-4-methylthiobutanoic acid. The method is characterized in that an ammonium phosphate aqueous solution produced by preparation of hydrocyanic acid and preparation of 2-hydroxy-4-methylthiobutanoic acid is treated inan ammonia separation tower and an ammonia purification tower and phosphoric acid and ammonia gas are separated and covered. The ammonia and phosphoric acid can be recycled repeatedly. The method simplifies acid-containing substance emission and treatment. The method has a unique technological process comprising pyrolysis separation of an ammonium phosphate aqueous solution after extraction, recycling of a phosphoric acid aqueous solution in hydrolysis of 2-hydroxy-4-(methylthio)butyronitrile and recycling of ammonium as a hydrocyanic acid preparation raw material. The method is environmentally friendly, reduces an environmental protection cost by 11.5%, has a high atom utilization rate, reduces a production cost by 21.8%, does not produce an ammonium salt by-product and reduces the pressure of sales and environmental protection.

Description

technical field [0001] The invention belongs to the preparation method of chemical products, relates to a clean preparation method of 2-hydroxy-4-methylthiobutyric acid (HMBA), and belongs to the technical field of chemical synthesis. Background technique [0002] 2-Hydroxy-4-methylthiobutyric acid (HMBA / liquid methionine) is generally considered the hydroxy congener of methionine, which is the congener of the essential amino acid L-methionine. Methionine congeners are effective in providing methionine as a nutrient, especially as a poultry feed supplement. [0003] The HMBA on industrial production is racemic D, the L mixture, and its preparation method is known, and this method comprises preparing 2-hydroxyl-4-methylthiobutyronitrile by methionaldehyde and hydrogen cyanide, and In the presence of excess mineral acid, sulfuric acid is generally used to hydrolyze the 2-hydroxy-4-methylthiobutyronitrile to obtain 2-hydroxy-4-methylthiobutyric acid. [0004] In US3773927A, H...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C319/20C07C323/52
Inventor 王志轩陈聪陈彦飞杨有得
Owner SHANDONG XINHECHENG AMINO ACID
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