Preparation method of hydroxy methionine salt and compound

Abstract

The invention provides a preparation method of hydroxy methionine salt and a compound, comprising the following steps: a. feeding metal hydroxide or basic metal oxide or amphoteric metal oxide and 2-hydroxy-4-methylthiobutyricacid into a closed and corrosion resistant reaction kettle to react for 0.5-12h according to a stoichiometric ratio, taking the low-boiling polar organic solvent or the mixed solvent thereof with water as the reaction medium, stirring, separating the target product, washing and drying to obtain the products; and b. recycling the reaction medium. The preparation method of the invention has short route, no consumption of acid or alkali reagent, low cost, easily-controllable product quality, environmental friendliness and the like, thus being applicable to large-scale industrial production.

Description

technical field [0001] 1. The present invention relates to the composite food or feed additive that can simultaneously supplement methionine, calcium and multiple trace elements (magnesium, manganese, iron, cobalt, nickel, copper, zinc) necessary for animal growth and development. [0002] 2. The present invention relates to the current technical route and process flow of hydroxymethioninate and organic trace elements, improving, innovating and developing the green chemical preparation and production process of high-quality hydroxymethioninate and complexes. Background technique [0003] Hydroxymethionine is also known as methionine hydroxyl analogue (MHA for short), and its trade name is The chemical name is 2-hydroxyl-4-methylthiobutyric acid (2-hydroxyl-4-(methylthio)butyric acid), which is a highly acidic organic acid (pH 1-2). It is formed by the reaction of 3-methylthiopropionaldehyde (3-(methylthio) propionaldehyde) and hydrocyanic acid (HCN) to generate the corresp...

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Problems solved by technology

But the problem that it exists is: have stronger corrosiveness and irritating smell, storage, transportation, inconvenient to use, must use expensive special-purpose liquid feeding system (Zhou Jiankang Chinese patent: a kind of compound that is used to supplement methionine and calcium and its production and preparation method, CN1493560A, on May 5th, 2004); the storage time is slightly longer (4 months), and the oligomers with less nutritional value in the liquid will multiply (up to more than 50mol%)

Although the direct mixing method has low equipment investment, simple process route and low production cost, it has obvious shortcomings: (1) It is difficult to carry out the reaction thoroughly

Because MHA itself is relatively viscous, and Ca(OH) 2 Or when CaO dry powder is reacted according to the stoichiometric ratio, even if the dead angle of the coulter type stirred reactor is not considered, it is easy to form the phenomenon that the raw material is wrapped and partially wrapped by the product, resulting in a decrease in the purity of the product; if the excessive MHA is formed during the reaction Fluid, it will increase the production cost, and the subsequent drying process will become more difficult (MHA has a high boiling point, about 170°C at 300Pa, higher at normal pressure)

(2) The product is difficult to dry, causing serious environmental pollution

The aqueous solution method can solve the problem that the target product is difficult to dry, and has a fast reaction rate and is environmentally friendly; but there are also many disadvantages: (1) The target product has low yield and poor purity

(2) Part of the content in the patent does not conform to the experimental facts

In the experiment, we found that even according to the optimal preparation conditions of the typical cases in the patent, iron hydroxymethionine still cannot be obtained; in addition, as stated by Professor D. Application Status: Interview with Professor Don Mahan of Ohio State University[J]. Chinese Journal of Animal Husbandry, 2007, 43(20): 51-53.), at present 'the only way to produce organic selenium is through yeast biosynthesis', put Organic selenium cannot be obtained by mixing inorganic selenium (selenium salt) with MHA; therefore, the patent is suspected of being overprotected

(3) Aqueous solution method prepares hydroxymethionine salt and complex, can produce a large amount of foams (as the MHA of organic acid can reduce the surface tension of water, produces foam on gas-liquid interface) in the reaction process, this can cause in industrial production Many disadvantages, such as reduced reactor production capacity, waste of raw materials, reduced product yield and purity, and potential safety hazards, etc.

Although the product prepared by this method can be used as a pharmaceutical preparation, the steps are cumbersome, the preparation process consumes a large amount of acid, alkali reagents and organic solvents, and the cost is high, so it is not suitable for industrial production of food or feed additives

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