2-naphthalenesulfonic acid, sodium naphthalene sulfonate and preparation thereof

Abstract

The invention relates to 2-naphthalene sulfonic acid, 2-sodium naphthalene sulfonate and a preparation technology thereof. The technical proposal is as follows: naphthalene and a little amount of anhydrous sodium sulfate are added to a reactor containing sulfuric acid with the concentration of 98% according to the mol ratio of the naphthalene to sulfuric acid being 1:0.1-0.5, and heated while stirring until the naphthalene and the anhydrous sodium sulfate are completely dissolved; SO3 gas is fed into the reactor within 1-3h for sulfonation reaction at the temperature of 120-180 DEG C; and then at the temperature of 150-180 DEG C, the naphthalene and the SO3 in the mixture obtained from the sulfonation reaction are blown away by compressed nitrogen gas when the mixture is stirred, so as to prepare the 2-naphthalene sulfonic acid. In addition, the prepared 2-naphthalene sulfonic acid can be added to a neutralization pot, and sodium sulfite solution with the concentration of 5%-15% which is preheated to 80-90 DEG C is added to the neutralization pot by a measuring tank, so the 2-naphthalene sulfonic acid and sodium sulfite solution can have neutralization reaction; crystallization and separation are carried out to obtain the 2-sodium naphthalene sulfonate. The preparation technology has the advantages of full utilization of the existing resources, high naphthalene conversion rate, good product quality, little environmental pollution, low cost and high economic benefits.

Description

technical field [0001] The invention belongs to the technical field of naphthalenesulfonic acid and its sodium salt. Specifically relates to a kind of 2-naphthalenesulfonic acid and 2-naphthalenesulfonic acid sodium salt and preparation technology thereof. Background technique [0002] 2-naphthalenesulfonic acid is the production of 2-naphthol (C 10 h 7 OH) is also a raw material for the synthesis of azo dyes. The naphthalenesulfonic acid formaldehyde condensate obtained by the further condensation of naphthalenesulfonic acid and formaldehyde is an important intermediate for pigments, dyes, dispersants for emulsification synthesis, and cement water reducers. [0003] The existing preparation methods of 2-naphthalenesulfonic acid mainly include concentrated sulfuric acid sulfonation method and gas SO 3 Sulfonation method. The traditional production method is to use the concentrated sulfuric acid process, generally need to use excess sulfuric acid during the reaction, oth...

AI Technical Summary

Problems solved by technology

But the process uses SO 3 Nitrogen or air mixed gas with a content of 1-50V% is used as a sulfonating agent, and the reaction produces a large amount of waste gas, and the tail gas needs to be passed into gas treatment facilities; a large number of kettle reactors used in traditional processes are converted into membrane or tube reactors Technical transformation is difficult, and it needs to be equipped with an additional aging device, which cannot make full use of existing resources and increases additional investment; so far, there have been no reports of this method being used in industrial production.