Method for industrialized continuous production of hydroxyacetonitrile

Abstract

The invention relates to a method applied to industrial continuous production of hydroxy acetonitrile. The method comprises the following steps: diluting a high-concentration formaldehyde raw material into low-concentration formaldehyde by using qualified hydroxy acetonitrile by virtue of a hydrocyanic acid hydroxyl methylation method, reacting the low-concentration formaldehyde with hydrocyanic acid to prepare a qualified hydroxy acetonitrile product; and extracting one part of the qualified hydroxy acetonitrile product as product collection and extracting the other part of the qualified hydroxy acetonitrile product as a circulation solution for diluting the continuously supplied high-concentration formaldehyde into low-concentration formaldehyde, continuously reacting the low-concentration formaldehyde with the continuously supplied hydrocyanic acid, and circulating in the manner to continuously produce the qualified hydroxy acetonitrile product. By virtue of the method, the industrial continuous production of the hydroxy acetonitrile is implemented; the produced hydroxy acetonitrile product is high in yield and extremely low in formaldehyde residue; the high-concentration industrial formaldehyde can be directly used; and the hydrocyanic acid serving as the raw material can be fully utilized.

Description

technical field [0001] The invention relates to a method for industrial production of hydroxyacetonitrile, in particular to a method for continuous production of hydroxyacetonitrile. Background technique [0002] Hydroxyacetonitrile, also known as glycolonitrile or formaldehyde cyanohydrin, is a colorless to light yellow liquid, highly toxic, can volatilize a mixed gas containing hydrocyanic acid in an open container, can dissolve some metals to form complexes, and is soluble It is widely used in chemical industry, dyestuff, medicine, pesticide and other fields. [0003] The preparation methods of hydroxyacetonitrile mainly include acetonitrile oxidation method and hydrocyanic acid hydroxymethylation method. The specific process of hydrocyanic acid methylolation method is: liquid formaldehyde and certain concentration of hydrogen cyanide gas are directly added to form hydroxyacetonitrile in a normal pressure equipment under an appropriate acid-base environment. Although th...

AI Technical Summary

Problems solved by technology

In the case of optimizing the raw materials and reaction conditions, the process is still troubled by the polymer produced in the reaction, which is an inherent defect that cannot be overcome by the process design: in the production process, although the liquid and gas phases of the raw materials are advanced The materials are all continuous, but the discharge is intermittent, and it is not continuous production in the true sense (the raw materials are continuously fed, the reaction is continuously carried out and the product is continuously withdrawn); along with the reaction, the accumulated hydroxyacetonitrile is getting more and more More, on the one hand, the reaction rate will be reduced and the conversion rate of raw materials will be reduced; on the other hand, under the reaction conditions, the generated products will be prone to polymerization or decomposition, which will reduce the product quality

[0010] Therefore, under the situation of utilizing industrialized raw materials and large-scale production, still lack a kind of production process of really continuous high-yield, high-quality hydroxyacetonitrile

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