Device and method for synthesizing 2,2-bipyridyl

Abstract

The invention discloses a device and method for synthesizing 2,2-bipyridyl, and belongs to the field of fine chemical engineering. The device comprises a preheater, reactors and discharge devices, each reactor is internally provided with a liquid distributor, a catalyst bed layer, a catalyst support plate and catalyst unloading device and a gas distributor in sequence from top to bottom, each discharge device comprises a regulating valve, and an aftertreatment device is an evaporator. According to the process, pyridine enters the reactors through the preheater and passes through the liquid distributors to be uniformly scattered on the catalyst bed layers, discharging is conducted through the regulating valve after a reaction is completed, unreacted pyridine is distilled and recycled through the evaporator for reuse, and the residue obtained after pyridine is distilled is 2,2-bipyridyl.

Description

technical field [0001] The invention belongs to the field of fine chemical industry, and in particular relates to a device and method for synthesizing 2,2-bipyridine. Background technique [0002] 2,2-Bipyridyl is an important fine chemical raw material, widely used in medicine, pesticide, analysis, electroplating and other industries, such as the production of diquat, additives for copper plating, color developers for the analysis of metal elements, etc. . [0003] The traditional production process of 2,2-bipyridine uses 2-chloropyridine as the raw material, which is formed by catalytic coupling with a catalyst. The traditional process has disadvantages such as large amount of catalyst, large amount of waste water and waste residue, serious corrosion of equipment, and high cost. GB899015, GB948956, GB1014076, US4966972, US315237, US3053846 and other documents mentioned that 2,2'-2,2-bipyridine was prepared by direct coupling of pyridine with catalyst. This process has goo...

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Problems solved by technology

[0003] The traditional production process of 2,2-bipyridine uses 2-chloropyridine as the raw material, which is formed by catalytic coupling with a catalyst. The traditional process has disadvantages such as large amount of catalyst, large amount of waste water and waste residue, serious corrosion of equipment, and high cost. GB899015, GB948956, GB1014076, US4966972, US315237, US3053846 and other documents mentioned that 2,2'-2,2-bipyridine was prepared by direct coupling of pyridine with catalyst. This process has good atom economy, no three wastes, no corrosion to equipment, and low catalyst consumption less, continuous operation and high degree of automation, the devices used in these documents are soaked fixed bed liquid-solid reaction, which has some disadvantages: ① The utilization rate of pyridine is not high, because only pyridine in contact with the catalyst can participate in the reaction, and the catalyst Most of the pyridine in the gap cannot participate in the reaction, resulting in a very low concentration of bipyridine, which in turn causes a large separation pressure; ②The reaction liquid contains poisons. If the catalyst is always soaked in the reaction liquid, it will cause catalyst poisoning

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