Method of producing 1-aminonaphthalene through fixed bed hydrogenation process

Abstract

The invention discloses a method of producing 1-aminonaphthalene through a fixed bed hydrogenation process. The method includes the following steps: loading a supported nickel catalyst in a fixed bed reactor and activating the catalyst; pumping a 1-nitronaphthalene solution into the fixed bed reactor and feeding hydrogen to perform a hydrogenation reaction; when the reaction is finished, collecting a reaction liquid, and performing distillation to remove the solvent to prepare the 1-aminonaphthalene. The supported nickel catalyst has very high hydrogenation activity and sulfur toxicity resistance, and is more than 5000 h in activity stability, can be recycled and is prolonged in service life, thereby reducing production cost. In addition, the method has simple process and convenient operation, is economical and safe, is high in productivity, reaction conversion rate and yield, and satisfies industrial production demands.

Description

technical field [0001] The invention relates to the technical field of fine chemical preparation, in particular to a method for producing 1-aminonaphthalene by a fixed-bed hydrogenation method. Background technique [0002] Menaphthylamine, also known as 1-aminonaphthalene, α-aminonaphthalene, α-naphthylamine or 1-naphthylamine, is a white needle crystal with an unpleasant smell. Slightly soluble in water, easily soluble in ethanol and ether. The product is an intermediate of various dye products such as direct dyes, acid dyes, ice dyes and disperse dyes. It is the main raw material of various rubber antioxidants and is also used in organic synthesis. The industrial production of menaphthylamine mainly adopts the nitration of industrial naphthalene to obtain nitronaphthalene and then reduces it to obtain menaphthylamine. The main reduction methods include alkali sulfide or iron powder reduction method and catalytic hydrogenation reduction method. The alkali sulfide reductio...

AI Technical Summary

Problems solved by technology

The industrial production of menaphthylamine mainly adopts the nitration of industrial naphthalene to obtain nitronaphthalene and then reduces it to obtain menaphthylamine. The main reduction methods include alkali sulfide or iron powder reduction method and catalytic hydrogenation reduction method. The alkali sulfide reduction method is as described in the patent CN101973894A. The production of carnaphthylamine by sulfur and caustic soda reduction has the following main disadvantages: low product yield, poor appearance, and a large amount of difficult-to-treat waste water and waste residues, which do not meet the requirements of clean production, high energy consumption, and do not meet energy conservation and emission reduction requirements. The requirements have been gradually replaced by the catalytic hydrogenation reduction method

The catalysts that have been industrialized mainly include palladium carbon and Raney nickel. However, due to the small amount of sulfur-containing compound impurities brought by industrial naphthalene, the catalyst is easily poisoned by sulfur-containing compounds in the actual hydrogenation process, and the catalyst cannot be recycled, resulting in high catalyst cost. high

Other catalyst reports include nickel-copper composite catalysts or nitrogen-doped carbon nanotubes, such as Chinese patents CN102304053A and CN105753717A, but they are still in the experimental stage at present, and no industrialization reports have been seen.

In addition, the catalytic hydrogenation synthesis of menaphthylamine in these prior art usually adopts intermittent production mode, which has low efficiency, low catalyst activity, low yield, needs continuous replenishment, less times of mechanical application, short life, and inconvenient operation. Or small test stage, industrial implementation is more difficult