Ethanol ammoxidizing process to synthesize high-purity acetonitrile

A technology for oxidative synthesis and ethanol ammonia is applied in the field of manufacture of aliphatic nitrile or carbocyclic and heterocyclic compound side chain nitriles, and can solve the problems of unsatisfactory acetonitrile yield, unstable product quality, and low acetonitrile recovery rate.

Inactive Publication Date: 2003-09-10
张华堂
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The defect of the existing method of acrylonitrile by-product acetonitrile is that the product quality is difficult to guarantee, the production energy consumption is high and the output is limited
Specifically, since the crude acetonitrile obtained by this method contains various impurities such as water, hydrocyanic acid, acrylonitrile, propionitrile, acetone, acetone cyanohydrin and oxazole, these impurities must all be obtained from crude acetonitrile to obtain pure acetonitrile Therefore, many complex separation and refining processes are required to realize it. At the same time, because the separation of these impurities is relatively difficult, the product quality is unstable; also due to the complexity of the separation process, the recovery rate of acetonitrile is low and the energy consumption is high; The yields of acrylonitrile and acetonitrile, the products of the propylene ammoxidation reaction, cannot be adjusted arbitrarily, that is, the ratio of the two products is roughly a constant value. Therefore, limited by the production of acrylonitrile, the production of acetonitrile cannot meet the demand for a long time

Method used

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  • Ethanol ammoxidizing process to synthesize high-purity acetonitrile
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  • Ethanol ammoxidizing process to synthesize high-purity acetonitrile

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Experimental program
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Effect test

Embodiment 1

[0102] The raw materials ethanol, ammonia and air in the gas phase are under the action of the ethanol ammoxidation catalyst in the fluidized bed reactor to produce acetonitrile as the main product and hydrogen cyanide as a by-product. The reaction gas mixture goes through a series of treatment and separation processes such as two-stage quench tower, packed absorption tower, plate recovery tower, decyanation tower, alkali dehydration tower, packed dehydration tower and finished product tower, and finally obtains the finished acetonitrile , while by-product sodium cyanide.

[0103] 1 reaction process

[0104] The liquid raw materials ethanol and ammonia are respectively vaporized and preheated to 130°C. After the two raw materials are mixed, they enter the reactor from the middle of the reactor. The lower part enters the reaction bed; the reaction raw material air from the air compressor enters from the bottom of the reactor, is evenly distributed through the air distribution ...

Embodiment 2

[0122] In the reaction process, ethanol and liquid ammonia are vaporized and preheated to 140-150°C respectively; the ammoxidation reaction is at 400-450°C; the pressure at the top of the reactor is 0.040-0.060Mpa gauge pressure; the linear velocity of the empty bed is 0.6-0.7m / s; Reaction weight hourly space velocity WWH0.15~0.2h -1 ;

[0123] In the recovery process, the spray liquid of the quenching tower is adjusted to pH 1~2, and the reaction gas is further cooled to 40~50°C; the temperature of the absorption water in the absorption tower is 5~7°C, and the mass flow ratio to acetonitrile is 17~22; the recovery tower absorbs The liquid is heated to 80-90°C; the top of the tower adopts external reflux, and the reflux ratio is 4.0-5.0. The sensitive point temperature control range of the stripping section is 90-95°C;

[0124] In the refining process, the reflux ratio at the top of the decyanation tower is 5.0-6.0, and the operating pressure is 0.08-0.10Mpa absolute pressure...

Embodiment 3

[0127] In the reaction process, ethanol and liquid ammonia are respectively vaporized and preheated to 90-100°C; the ammoxidation reaction is at 350-400°C; the pressure at the top of the reactor is 0.025-0.030Mpa gauge pressure; the linear velocity of the empty bed is 0.4-0.5m / s; Reaction weight hourly space velocity WWH0.10~0.15h -1 ;

[0128] In the recovery process, the spray liquid of the quenching tower is adjusted to pH 4-5, and the reaction gas is further cooled to 30-40°C; the temperature of the absorption water in the absorption tower is 2-3°C, and the mass flow ratio to acetonitrile is 12-15; the recovery tower top The reflux ratio is 3.0-4.0, and the temperature control range of the sensitive point in the stripping section is 60-70°C;

[0129] In the refining process, the reflux ratio at the top of the decyanation tower is 3.0-4.0, and the operating pressure is 0.06-0.08Mpa absolute pressure; the ratio of the reflux flow at the top of the dehydration tower to the a...

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Abstract

The present invention belongs to preparation of aliphatic nitrile or carbocycle and heterocycle compound side chain nitrile, and is especially ethanol ammoxidizing process to synthesize high-purity acetonitrile. Fluidized bed catalytic reaction technology and continuous recovering and refining technology are adopted; and the process features the utilization of ethanol, ammonia and air as main material. Compared with available technology, the acetonitrile product has purity has high as 99.9% and less kinds of impurity, lower power consumption and less waste and waste gas prdouced. The product may be further processed into chromatographic product.

Description

technical field [0001] The invention belongs to the production method of aliphatic nitrile or carbocyclic and heterocyclic compound side chain nitrile, in particular to a method for synthesizing high-purity acetonitrile by ethanol ammoxidation. Background technique [0002] Acetonitrile (acetonitrile, ethanenitrile, CH 3 CN), also known as methyl cyanide, is an important fine chemical intermediate product and chemical solvent. Acetonitrile is an intermediate of medicines and spices, and is a raw material for the manufacture of triazine nitrogen fertilizer synergists; it is also used as a denaturant for alcohol; in organic synthesis, it is used to make triazines, ethylamines, dipropionitrile, imidazoles, Propyl bisacetonitrile etc. Acetonitrile can be used as an extractant for extracting butadiene and isoprene, a spinning solvent for synthetic fibers and a solvent for some special coatings; it is used as a solvent for removing tar, phenol and colored substances from petrole...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C253/24C07C255/03
Inventor 张华堂张英男陈静
Owner 张华堂
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