SU48320A1 - Method and apparatus for producing dry aniline hydrochloride from aniline and hydrochloric gas - Google Patents

Description

At present, the production process of aniline hydrochloride salt production is a method of salt formation in an aqueous solution of dilute hydrochloric acid and aniline, taken in equivalent amounts. After crystallization, the resulting aniline hydrochloride salt is squeezed onto centrifuges and dried. An addition of a less pure aniline salt to the uterine salt solution is added.

The ideal way to obtain the hydrochloric salts of organic bases is to recognize their formation from gaseous hydrogen chloride, i.e., using the latter as it is formed in production in sulphate furnaces from cooked SOL and obtained by synthesis.

Recently, several patents have been discovered that protect methods for the direct use of hydrogen chloride for the preparation of salts of organic bases.

In Amer. pat No. 1843705 describes a method for producing aniline hydrochloride salt by passing gaseous hydrogen chloride to aniline with mechanical agitation.

By Amer. pat No. 1843693, aniline salt is obtained by passing aniline and hydrogen chloride on the countercurrent principle through a tower with a nozzle at a temperature above the melting point of aniline salt.

In French pat No. 691911 and English, Pat. No. 3,28210 proposes methods for the separation of xylidine isomers as hydrochloric salts using water-immiscible solvents for this purpose (benzene, gasoline), in which xylidine solution is passed dry hydrochloric gas.

In the owls. pat Fedorov describes a method for producing aniline hydrochloride salt from gaseous hydrogen chloride and aniline, based on the following principle: if you enter sprayed aniline on one side into a hollow cylindrical chamber, and dry on the other side; gaseous hydrogen chloride, the aniline salt is formed. Aniline was sprayed using a pressure spray.

The subject of the present invention is a process for the preparation of aniline hydrochloride salt from gaseous hydrogen chloride and aniline film. The proposed method is as follows. From the iron mongee 8, aniline is supplied with compressed air to the pressure tank 7.

From the iron pressure tank, aniline enters by gravity into a lead pan 4,

 t. .

The stainless steel drum 7 of the stainless steel mold 7 is wetted with aniline to form an aniline film.

The mold rotates with an electric motor and makes up to five; rpm. At this rate of rotation of the mold, the thickness of the aniline film on its cylindrical porhrhness reaches about 0.1 mm. The film of aniline, when the crystallizer rotates, falls under the iron switchboard 3, from which hydrogen chloride gas flows through a series of holes, arranged in a shakhmatny order. The switchboard is divided into several compartments serving to evenly distribute the gas on the surface of the aniline film.

Each compartment has a lead pipe; Hydrochloric gas enters the wire, which is controlled by the help of a rotameter 6.

The hydrochloric gas is supplied with some excess. Upon exiting the switchboard, the hydrochloric gas of b interacts with the film:, aniline, with the result that aniline hydrochloride forms on the top of the nostrum of the crystallizer.

Aniline hydrochloride obtained

is cleaned with a knife 2 from the surface of the rotating mold and

through the bunker is poured into the container.

The reaction of formation of hydrochloric acid

aniline is accompanied by secretion

a heat that is taken away by cooling water that flows into the interior of the drum through a hollow shaft.

; Excess hydrochloric gas

is removed from the iron fan, the casing in which the mold 5 is enclosed, to the hydrochloric acid plant. The casing is covered with bakelite lacquer. On the way from the casing to the installation to obtain hydrochloric acid, excess hydrochloric gas is purified in the cyclone 9 from the partly carried away dust of hydrochloric aniline.

The yield of the hydrochloride salt of aniline is quantitative. From technical aniline, the purity of the salt is 97.3%.

This method can be extended without any changes to obtain the hydrochloride salts of other organic bases.

The proposed method for producing aniline hydrochloride salt has the following advantages:

1. The time course of the aniline salt formation process is significantly reduced.

2. Efficiency and compactness of the process, since crystallization, centrifugation, the substance, etc., are eliminated.

3. Continuity of the aniline salt production process.

4. Full use of aniline.

5. The possibility of using gaseous hydrogen chloride, obtained directly on sulphate furnaces or by synthesis.

The subject matter of the invention.

1. A method for producing dry aniline hydrochloride from aniline and hydrochloric gas, characterized in that aniline is introduced as a thin film in contact with hydrochloric acid gas.

2. An apparatus for carrying out the method mentioned in Clause 1, constructed according to a type of drum crystallizer cooled from the inside, characterized in that the drum crystallizer / equipped with a knife 2 with a stripping crystal is immersed in its bottom 4 with aniline in order to grab the latter and distribute when the drum rotates / in a thin layer on its surface, and in the upper part it is surrounded by a switchboard 3 with small holes for the influx of hydrochloric gas and bringing it in contact with a thin film of aniline on a rotating, cooled inside the drum.