A kind of method for producing nicotinamide by continuous hydrolysis of 3-cyanopyridine

Abstract

The invention discloses a method using 3-cyanopyridine continuous hydrolysis to produce nicotinamide. The method has the advantages that continuous nicotinamide production using the 3-cyanopyridine hydrolysis is achieved, and the conversion rate of 3-cyanopyridine can reach 95%; the method mainly uses a fluidized bed catalytic hydrolysis reactor, a deactivated catalyst filtering and discharge andfiltrate loop is arranged at the bottom of a dense-phase section above a distribution plate, and a dilute-phase section is provided with a fresh catalyst storage tank and a valve for adding a catalyst; the continuous production is achieved through the fluidized bed catalytic hydrolysis reactor, raw material retention time is increased and high conversion rate in the continuous production is achieved by a circulation loop arranged at the outlet of the reactor, continuous catalyst replacing can be achieved under a stable operation environment through a catalyst replacing bypass, and shutdown caused by catalyst deactivation is avoided.

Description

technical field [0001] The invention belongs to the technical field of fine chemicals, and in particular relates to a method for continuously hydrolyzing 3-cyanopyridine to produce nicotinamide. Background technique [0002] Niacinamide is a water-soluble derivative of vitamin B3, which plays a role in transferring hydrogen atoms in the biological oxidation respiratory chain, can promote biological oxidation and tissue metabolism, and has a certain effect on maintaining the integrity of the skin, digestive tract and nervous system. important role. In addition, nicotinamide can be used as an additive in feed, a pharmaceutical intermediate and a nutritional enhancer in food to prevent pellagra and cardiovascular diseases. It is a very important food additive in today's society. [0003] At present, the synthesis process of nicotinamide is mainly divided into three steps: 1) cyclization to cyclize the chain organic molecule into a pyridine ring containing a methyl group; 2) me...

AI Technical Summary

Problems solved by technology

Although the microbial method has high product purity, it is a batch production process and the operating conditions are complicated and difficult to control, and the strains are easy to deteriorate, which affects the reaction and product quality.

[0006] To sum up, a large amount of liquid ammonia is required to produce nicotinamide by the ammonia oxidation method, which brings many hidden dangers to safe production; while the existing chemical and biological methods are all intermittent operations

Chemical separation is difficult, energy consumption is high, and environmental pollution is large; the operating conditions of the microbial method are not easy to control and the product quality is unstable

Images