Fluid-bed catalyst for ammoxidation of aromatic hydrocarbon

Abstract

A granular fluidized-bed catalyst for ammoxidizing arylhydrocarbon to preparing arylnitrile has a chemical formula: V1.0CraTibAcBdCeOx, where A is chosen from P, B, Bi, Sb and As, B is chosen from alkali metals and alkali-earth metals, and C is choosen from Mn, Ni, Co, Sn, Pb, Fe, Mo, W and ER. Its advantage is high output rate.

Description

technical field [0001] The invention relates to a fluidized bed catalyst for the ammoxidation of aromatic hydrocarbons, in particular to a fluidized bed catalyst for the ammoxidation of substituted aromatic hydrocarbons or heterocyclic aromatic hydrocarbons. Background technique [0002] Due to the chemical activity of the aromatic nitrile cyano group, a series of fine chemical products can be synthesized through hydrolysis, hydrogenation, addition or polycondensation reactions, which are important raw materials for the manufacture of pesticides, medicines, dyes, spices, resins, etc. For example, 2-cyano-4-nitroaniline can be obtained through nitration ammonolysis reaction of o-chlorobenzonitrile, which is an important intermediate of various azo disperse dyes; p-chlorobenzonitrile is used to prepare high-grade car paint Pigments; isophthalonitrile (abbreviated as IPN), tetrachloroisophthalonitrile synthesized by chlorination is an efficient and low-...

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Problems solved by technology

Sb catalyst has good activity, but due to factors such as the complicated preparation method of Sb catalyst and special requirements for reactors, the economics of this catalyst, especially for small batches of multi-variety aromatic hydrocarbon ammoxidation products, are unreasonable.

The V-Cr catalyst is relatively simple to prepare, has good repeatability, and has high reactivity for the ammoxidation of aromatic hydrocarbons, but it is easy to cause deep oxidation and has strong decomposition ability for ammonia.

[0005] There are many kinds of multi-component catalysts for the ammoxidation of alkylaromatics to prepare aromatic nitriles, such as ternary composition catalysts: V-Cr-B (JP19284), with SiO 2 As a carrier, fixed bed evaluation, the product yield has reached a good level, but with the increase of the reaction time, the catalytic activity of the catalyst has a downward trend, so it is difficult to industrialize; V-Cr-Ba (JP61-4388) is made of SiC Carrier, at a temperature of 370°C, fixed bed evaluation, the yield of benzonitrile is 82.3%, and the best yield of isophthalonitrile is 54.0%

Quaternary composition catalyst: V-Cr-B-Mo / SiO 2 (JP01-275551), V-Cr-B-P / SiO 2 (JP76-15028), V-Cr-Sn-P / SiO 2 (JP Zhao 45-19285) are the patents disclosed by Mitsubishi Gas and Nippon Chemical Gas Corporation respectively. Under the conditions of 410°C, 412°C, and 435°C respectively, the small-scale fixed-bed evaluation shows the best yield of benzonitrile 83.3%, 85.2%, and 83.2%, when used for the ammoxidation of picoline to prepare the corresponding heterocyclic aromatic nitrile, the product has reached a good yield; but the reactivity and stability are not ideal, and the wear resistance of the catalyst is relatively poor; the reaction By-products especially CO, CO 2 , HCN content is still high; Mitsubishi Gas announced V-Cr-B-P-Mo / SiO in the 1990s 2 (EP0525367A 1 ) five-component catalyst, but the catalyst must use more expensive phosphomolybdic acid or ammonium phosphomolybdate raw materials in order to obtain ideal reaction results

Generally speaking, the fixed bed inspection results show that the yield of aromatic nitrile is 3-5% higher than that of the fluidized bed, so it is difficult for the above-mentioned catalysts to truly represent the actual level of the fluidized bed catalyst

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