Method for producing high purity 2-hydroxy-3-naphthoic acid

Abstract

Disclosed is a method for producing a high purity 2-hydroxy-3-naphthoic acid. The method includes a 2-naphthol measuring tank, a caustic soda liquid storage tank, a caustic soda liquid measuring tank, a salt forming reaction vessel, carbon dioxide, a carbonization kettle, a resin separation, a resin solid waste, a dilute sulfuric acid, a neutralization, a filter pressing, a filter cake distillation, a 8% sodium hydroxide, a resin adsorption, an acid eduction, a sewage treatment workshop, a centrifugal dewatering, a pneumatic drying and finishing of a high purity 2-hydroxy-3-naphthoic acid product. The caustic soda liquid storage tank is downwards connected to the caustic soda liquid measuring tank, the caustic soda liquid measuring tank is connected to the salt forming reaction vessel, the salt forming reaction vessel is downwards connected to the carbonization kettle, simultaneously the carbon dioxide is connected to the carbonization kettle, 2-naphthol generated by reaction in the carbonization kettle and 2-naphthol obtained by the filter cake distillation are connected to the 2-naphthol measuring tank, the carbonization kettle is downwards connected to the resin separation, and simultaneously the resin separation is upwards connected to an ethyl naphthol feed liquid and the dilute sulfuric acid and downwards connected to the neutralization and the resin solid waste. According to the method, the whole process is simple, the operation and the usage are convenient, the stability is good, and the reliability is high.

Description

technical field [0001] The invention relates to a production process of organic chemical products, in particular to a production method of high-purity 2-hydroxy-3-naphthoic acid. Background technique [0002] 2-Hydroxy-3-naphthoic acid is an organic chemical intermediate, which is mainly used in the production of organic pigments and naphthol series products, and can also be used in the pharmaceutical industry. Its conventional production process is as follows: first, 2-naphthol and liquid caustic soda are reacted in a sodium salt pot to generate 2-naphthol sodium salt, and then transferred to a carbonization kettle for dehydration to obtain anhydrous 2-naphthol sodium salt, and then pass through carbon dioxide to carry out carboxylation, and then go through several processes of resin separation, neutralization, and pressure filtration to remove the by-products and incompletely reacted 2-naphthol, and finally go through acid precipitation, centrifugation, drying and other pr...

AI Technical Summary

Problems solved by technology

In the conventional production process, reducing the content of 2-naphthol mainly depends on reducing the temperature of the neutralizing solution as much as possible to reduce the solubility of 2-naphthol, which not only has limited effect but also wastes a lot of water resources, so the development A new process to improve the purity of 2-hydroxy-3-naphthoic acid is imperative

Images