A kind of preparation method of 2-hydroxy-4-methylthio-calcium butyrate

Abstract

The invention discloses a preparation method for 2-hydroxy-4-methylthio-calcuim butyrate. The method is characterized by comprising the following step of reacting reaction raw materials comprising a 2-hydroxy-4-methylthio-butyric acid solution and one or more of calcium hydroxide, calcium oxide and calcium carbonate with ammonium bisulfate introduced as an organic reaction catalyst to obtain the 2-hydroxy-4-methylthio-calcuim butyrate. The method has the advantages of being mild in reaction, free of specific stirring tools, high in universality, less in equipment investment, low in production cost, convenient to use, mild and controllable in the whole reaction process, low in probability of product decomposition or coking rate, complete in reaction, time-saving, high in product yield, purity and yield, energy-saving and more environment-friendly.

Description

technical field [0001] The invention relates to the technical field of food or feed additive production methods, in particular to a preparation method of 2-hydroxy-4-methylthio-butyrate calcium. Background technique [0002] 2-Amino-4-methylthio-butyric acid, commonly known as calcium hydroxymethionine (CASNo.4857-44-7); is often used in animal feed as an amino acid feed additive. It is an animal growth promoter, It is used for protein synthesis, which can improve animal growth rate and poultry egg production rate, but the traditional methionine preparation method, refer to the Chinese patent "methionine preparation method" with patent number 99107001.1, which is under the condition of the presence of potassium carbonate. 5-Hydantoin is hydrolyzed, and then carbon dioxide is passed into the hydrolyzate for neutralization, so that methionine crystallizes out. However, this process has the disadvantages of huge production investment, expensive equipment, complex technology, l...

AI Technical Summary

Problems solved by technology

But, the preparation method of above-mentioned 2-hydroxyl-4-methylthio-butyric acid calcium has the following defects: when solid state calcium oxide or calcium hydroxide and liquid state 2-hydroxyl-4-methylthio-butyric acid start It is difficult to mix and the reaction is also difficult, but once the two react, the reaction will be very violent and the reaction speed will be very fast. On the one hand, the pressure in the reaction vessel will increase rapidly and a large amount of heat will be generated, resulting in Reaction rate, pressure and temperature are difficult to control, and after temperature is greater than 130 degrees, product 2-hydroxyl-4-methylthio-calcium butyrate can decompose or coke, on the other hand, a part of material (such as calcium oxide or hydroxide Calcium or intermediate products, etc.) are easily wrapped into large groups or large pieces, unable to fully participate in the reaction, resulting in a relatively insufficient amount of reaction raw materials, insufficient reaction, more intermediate products, and low product purity, thereby affecting product yield and quality

Moreover, after the material is wrapped into large balls or chunks, the moisture inside is difficult to evaporate during drying, which affects the overall drying of the material and greatly prolongs the drying time of the material, resulting in a longer production time and affecting the output.

[0004] The applicant applied for the application number 2012100885716 on March 30, 2012, and the title is "A Preparation Method for Calcium 2-Hydroxy-4-Methylthio-Butyrate". In this patent application, the applicant, in order to overcome the oxidation of solid state Calcium or calcium hydroxide reacts violently with 2-hydroxy-4-methylthio-butyric acid in liquid state, and the reaction speed is very fast to generate a large amount of heat, which makes the reaction speed, pressure and temperature difficult to control. A knife-type mixing dryer is used to enhance the stirring intensity, and strict control of the material feeding sequence and reaction temperature is used to prevent coking; but the above-mentioned technical solution still has the following deficiencies: 1. First, although the late 2-hydroxyl-4-methylsulfide in this application The reaction between base-butyric acid and calcium carbonate is relatively gentle, but the violent reaction between calcium hydroxide or calcium oxide and 2-hydroxy-4-methylthio-butyric acid in the early stage is still inevitable, and there is still a high reaction temperature, which is easy to cause The risk of coking of the product, so the use of a coulter-type mixing dryer with strong stirring force makes the reaction relatively mild; but this results in the need to use a specific coulter-type mixing dryer, which has poor versatility and narrow operating range; 2. Secondly, This reaction drying time is long, and the protracted production cycle will certainly cause the deficiency of high cost and time-consuming to the producer; 3. solid calcium hydroxide or calcium oxide or calcium carbonate and liquid 2-hydroxyl-4-methylthio-butyl The problem of poor solubility between acids still exists, which will inevitably cause raw materials to agglomerate, and the reaction is insufficient and thorough; reaction, causing the entire reaction rate and time to be difficult to control, and the product is prone to pyrolysis