Continuous nitrification method of naphthalene sulfonate compound

Abstract

The invention belongs to the field of organic synthesis, and particularly relates to a continuous nitrification method of a naphthalene sulfonate compound. The method comprises the steps of simultaneously and continuously making the nitrified matter naphthalene sulfonate compound and a nitrating agent enter a channel of a stainless steel annular reaction device under a water bath and supersonic environment through a metering pump on the basis that the nitrate ratio is 1.0-1.4 or 2.1-2.4, performing a mixing reaction for 40-120 s under mechanical action generated by supersonic and at 20-70 DEG C, and conducting discharging continuously after the reaction. According to the continuous nitrification method of the naphthalene sulfonate compound, a sulfuric acid solution and acid for nitration of the naphthalene sulfonate compound enter the annular channel simultaneously and continuously through the metering pump, and are mixed sufficiently by suffering from influences of mechanical effects of vibration, internal friction and the like generated by centripetal force and supersonic of liquid flow exerted on a liquid, and the reaction is completed.

Description

technical field [0001] The invention belongs to the field of organic synthesis, and in particular relates to a continuous nitration method for naphthalenesulfonic acid compounds. Background technique [0002] Naphthalenesulfonic acid nitro compounds are important intermediates for the production of acid dyes, direct dyes, reactive dyes and other types of dyes. The preparation method generally uses sulfuric acid as a solvent, adding nitric acid or nitric acid mixed acid in the reaction kettle. The intermittent nitration method conduct. The production of naphthalenesulfonate nitro compounds has the characteristics of large heat release, fast heat release rate, and easy overheating of the system. The production mode of intermittent nitration in a reactor has small heat transfer area, high risk, and low production efficiency. [0003] The Czech patent CS204080 and the Japanese patent JP58128364 respectively proposed a method for preparing 1-nitro-3,6,8-trisulfonic acid by conti...

AI Technical Summary

Problems solved by technology

The production of naphthalenesulfonic acid nitro compounds has the characteristics of large heat release, fast heat release rate, and easy overheating of the system. The production method of intermittent nitration in a reactor has small heat transfer area, high risk, and low production efficiency.

[0003] The Czech patent CS204080 and the Japanese patent JP58128364 respectively proposed a method for preparing 1-nitro-3,6,8-trisulfonic acid by continuous nitration in series in series, both of which improved production efficiency to varying degrees and reduced labor intensity , but due to the limitation of the heat transfer capacity of the reactor, the progress in improving efficiency and increasing safety is limited

[0004] Chinese patent CN102320995 proposes a tubular continuous nitration method for naphthalene-2,7-disulfonic acid in the production of H acid, using a tubular reactor with packing or mixing components inside and a jacket outside, and the material is continuous Through a tubular reactor, the reaction temperature is 40-50°C, and the reaction time is 60 minutes, but the specific reaction effect is not mentioned, and it is not known whether it has practical application value

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