Method for recovering pyridine from waste pyridine hydrochloride and cyclically reutilizing pyridine

Abstract

The invention provides a method for recovering pyridine from waste pyridine hydrochloride for producing chloromethyl isopropyl carbonate and cyclically reutilizing the pyridine. The method comprises the following process steps that: the pyridine hydrochloride and water are placed into a container according to a proportion being 1:2 to be stirred to obtain pyridine hydrochloride water solution, the pyridine hydrochloride water solution and two times of pyridine hydrochloride liquid caustic soda are placed into an enamel reaction kettle to be sufficiently stirred for taking reaction to generate pyridine and sodium chloride water solution, the pyridine and sodium chloride water solution are automatically produced in the still state, the upper layer is water-containing pyridine, the lower layer is sodium chloride water solution, the water-containing pyridine at the upper layer is taken out and is subjected to impurity removal through precipitation, rectification elution is adopted for removing water to obtain finished products, and the sodium chloride water solution is conveyed into a concentration pot to be concentrated to obtain sodium chloride finished products. The finished product pyridine can be used as one ingredient to be conveyed into a chloromethyl isopropyl carbonate production process line to be cyclically utilized for producing chloromethyl isopropyl carbonate. The method has the advantages that the resource waste is reduced, the environment cannot be polluted, meanwhile, the production cost of the chloromethyl isopropyl carbonate is also greatly reduced, and the economic benefits of enterprises are improved.

Description

technical field [0001] The invention relates to a method for recovering and recycling pyridine from waste pyridine hydrochloride produced from chloromethyl isopropyl carbonate. Background technique [0002] Pyridine hydrochloride is produced as waste during the production of chloromethyl isopropyl carbonate. After the condensation reaction of chloromethyl isopropyl carbonate is finished, filter out waste pyridine hydrochloride, every ton of chloromethyl isopropyl carbonate will produce 0.9 tons of waste pyridine hydrochloride. If this waste is incinerated, it will generate phosgene COCl2 that pollutes the environment. Incineration of pyridine hydrochloride will also cause waste of resources and increase of production costs. Pyridine hydrochloride is packed in bags, and the bags are easily corroded and pollute the environment. There is a large amount of pyridine in pyridine hydrochloride. However, pyridine is less produced domestically, and most of it depends on imports. ...

AI Technical Summary

Problems solved by technology

Pyridine is less produced domestically, and most of it depends on imports

When international resources are tight, the import of pyridine from abroad is unstable and sometimes seriously affects the production of enterprises