Method and apparatus for electrolytic synthesis of 3,6-dichloropyridine-carboxylic acid

Abstract

The invention discloses a 3, 6- dichloro pyridine methanamine electrolytic synthesis method and device, which comprises the following steps: using 3, 4, 5, 6-tetrachloro pyridine aminic acid for main electrolysis material; placing electrolytic solution in electrolysis bath to electrolyze; getting 3, 6- dichloro pyridine methanamine by neutralizing, cooling, crystallizing, filtering and drying; carrying on toughening treatment for cathode of electrolysis bath by periodic reversible power of thyristors. The device is composed of power, dosage bunker, electrolysis bath, wherein the power is stabilized voltage and permanent flow, which can control the cycle reverse power; the power connects to current commutator; program control unit is installed for current commutator; the anode of power is connected to anode of electrolysis bath; the minus pole of power connects to cathode of electrolysis bath.

Description

(1) Technical field [0001] The invention relates to an electrolytic synthesis method of 3,6-dichloropicolinic acid, and also relates to an electrolytic synthesis equipment of 3,6-dichloropicolinic acid. (2) Background technology [0002] The English name of 3,6-dichloropicolinic acid is 3,6-dichloropicolinic acid, commonly known as Bikecao. 3,6-Dichloropicolinic acid (3,6-D) is a highly active plant growth regulator. Since the publication of US3317549, 3,6-D has attracted more and more attention, especially in the control of 2,4-D (2,4-dichlorophenoxy)acetic acid and MCPA (2-methyl- Herbicide-resistant plants such as 4-chlorophenoxy)acetic acid are very effective, such as Canada thistle, Russian nettle and wild buckwheat are very sensitive to 3,6-D. 3,6-D is also very active on pasture shrubs, such as nettle, cat's claw acacia (a kind of silk tree), mesquite is also very sensitive to 3,6-D. In addition, 3,6-D is not only less toxic to mammals, fish and poultry, but also h...

AI Technical Summary

Problems solved by technology

The method has the following disadvantages: (1) the amount of dichloromethane is large, and 90% of the 3 in the filtrate is extracted, and the volume of 6-D needs to use dichloromethane to be about three times of the volume of the filtrate; (2) the energy consumption is high, and two Although the boiling point of methyl chloride is low, a large amount of dichloromethane needs to be heated and volatilized, and the energy consumption cannot be ignored; (3) the loss of dichloromethane is serious, because the boiling point of dichloromethane is low, so dichloromethane is easy to volatilize in use (4) Serious pollution, dichloromethane is a highly toxic solvent, and dichloromethane volatilized into the air seriously endangers the health of operating workers and residents around the factory

This method better solves the problems of high energy consumption and serious loss of dichloromethane in conventional separation methods provided by US4217185, etc., but the increase in operation steps makes the process complicated, and the use of toxic chemical dichloromethane cannot be avoided at the same time

Images