A method for preparing acetonitrile by catalyzing zirconium-tungsten mesoporous molecular sieves

Abstract

The invention provides a method for preparing acetonitrile by applying a zirconium tungsten mesoporous molecular sieve catalyst. The method comprises the following steps that raw material acetic acid and ammonia are preheated after being vaporized respectively, the molar ratio of the acetic acid to the ammonia is 1:2.5-7, the acetic acid and the ammonia enter a mixer to be mixed, and then enter a static bed containing the zirconium tungsten mesoporous molecular sieve catalyst to carry out a catalytic reaction, the reaction temperature ranges from 360 DEG C to 450 DEG C, and reaction gas is absorbed by water to obtain an acetonitrile product; the zirconium tungsten mesoporous molecular sieve catalyst is formed by loading ZrO2 and WO3 on a mesoporous molecular sieve. According to the method, the acetic acid and the ammonia are used as raw materials, by means of the static bed reactor, under the effect of the zirconium tungsten mesoporous molecular sieve catalyst, an ammonification method is used for synthesizing the acetonitrile, the zirconium tungsten mesoporous molecular sieve catalyst is good in stability, the selectivity conversion rate is high, and the product yield is high.

Description

Technical field [0001] The invention belongs to the field of chemical industry, and relates to a method for preparing high-purity acetonitrile by an acetic acid amination method, in particular to a method for preparing high-purity acetonitrile by using zirconium tungsten mesoporous molecular sieve as catalyst. Background technique [0002] Acetonitrile is a colorless liquid with a pungent odor. It is miscible with water and soluble in most organic solvents such as alcohol. Acetonitrile melting point: -45.7℃, boiling point: 81.1℃, density: 1.42, refractive index: n20 / D 1.419 (lit.), flash point: 2℃, saturated vapor pressure (kPa): 13.33 (27℃), heat of combustion ( kJ / mol): 1264.0, critical temperature (℃): 274.7, critical pressure (MPa): 4.83, upper explosion limit% (V / V): 16.0, ignition temperature (℃): 524, lower explosion limit% (V / V ): 3.0. [0003] The main purpose of acetonitrile is as a solvent. For example, as a solvent for extracting butadiene, a solvent for synthetic fi...

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Problems solved by technology

[0005] 1. Acrylonitrile by-product method, the production capacity of this process route is restricted by the production of acrylonitrile, and the product has many impurities, so it is difficult to meet the requirements of pharmaceutical grade indicators

[0006] 2. Synthesis of acetonitrile from methanol and ammonia. The yield of this process route is low. According to literature reports, the yield is less than 60%. Hydrogen is a flammable and explosive gas, so the possibility of this process for production is not great

[0008] 4. Sodium cyanide reacts with dimethyl sulfate to synthesize acetonitrile. The raw materials of this process are highly toxic substances. If used improperly, it will cause serious consequences

[0010] 6. Acetonitrile is synthesized by ethanol ammoxidation method, the yield is low, and the content of hydrocyanic acid is high