Technological method for jointly preparing liquid hydrogen cyanide and bisisobutyronitrile hydrazine

Abstract

The invention provides a technological method for jointly preparing liquid hydrogen cyanide and bisisobutyronitrile hydrazine. The technological method comprises the steps that a light oil cracking hydrogen cyanide gas mixture is used as a raw material and undergoes an ammonia removal process and a cryogenic process to obtain liquid hydrogen cyanide, wherein in the ammonia removal process, the hydrogen cyanide gas mixture is absorbed with a sulfuric acid aqueous solution; in the cryogenic process, the hydrogen cyanide gas mixture is cooled to minus 10-minus 20 DEG C, after the hydrogen cyanide gas mixture is cooled, a part of the hydrogen cyanide gas becomes liquid to obtain liquid hydrogen cyanide, and the other part of the hydrogen cyanide gas is the tail gas containing hydrogen cyanide; the tail gas containing hydrogen cyanide, which undergoes cryogenic treatment, is absorbed with a ketazine aqueous solution to obtain an aqueous solution containing bisisobutyronitrile hydrazine, and the aqueous solution containing bisisobutyronitrile hydrazine undergoes cooling, crystallization and centrifugal filtration to obtain a bisisobutyronitrile hydrazine crystalline solid. By adopting the technological method, the purification efficiency and the utilization efficiency of hydrogen cyanide can be obviously improved, meanwhile, the energy consumption in the hydrogen cyanide purification process is greatly reduced and can be reduced by 90% at most, and the utilization rate of hydrogen cyanide is more than 99.9%.

Description

technical field [0001] The invention belongs to the field of chemical industry, and relates to a method for purifying hydrocyanic acid from a reaction mixture gas produced by cracking light oil and producing diisobutyronitrile hydrazine by utilizing tail gas. Background technique [0002] Hydrocyanic acid is a widely used chemical raw material, which can be used in many fields such as medicine, pesticides, cosmetics, dyes, fertilizers, electroplating, polymer materials, photography, mining, metallurgy, etc. At present, the main production methods of hydrocyanic acid mainly include light oil cracking method, Andrussow method, BMA method and acrylonitrile by-product method. Light oil cracking is a production method in which light oil (or gasoline), liquid ammonia and caustic soda are used as the main raw materials, and petroleum coke particles and nitrogen are used as auxiliary raw materials. Mixing, preheating to 280°C, immersing the petroleum coke particle layer through the...

AI Technical Summary

Problems solved by technology

But because the preparation of acetone cyanohydrin needs to use the liquid hydrocyanic acid of high purity, so its cost of preparing diisobutyronitrile hydrazine by acetone cyanohydrin method is higher

[0005] The above methods have complex hydrogen cyanide purification process, high cost, high energy consumption; or low utilization rate of hydrogen cyanide, etc., which are difficult to accept in industrial production