Concentrated acid hydrolysis system used for organochlorosilane concentrated acid hydrolysis

Abstract

The invention relates to a concentrated acid hydrolysis system for concentrated acid hydrolysis of organochlorosilane, which takes a dispersed liquid membrane analysis tower as the core and also includes accessory equipment: a static mixer, an oil-water phase separator, and a falling film evaporator. The analysis tower includes a shell. A liquid distribution plate is fixedly installed between the upper head and the outer cylinder of the analysis tower. The upper part of the liquid distribution plate is a splash-proof wire mesh, and the lower part of the liquid distribution plate is a neatly arranged film-forming plate. The film-forming plates are horizontally supported, with a total of 3 to 10 layers. The angle between the forming template and the horizontal plane is 15 to 75 degrees. Between the layers, the film-forming plates are arranged in staggered directions. In the present invention, the HCl gas produced by hydrolysis has sufficient pressure through appropriate reaction pressure (0.1-0.5MPa gauge pressure). The dispersion liquid membrane desorption tower is used to contact the organic phase and the water phase in a film-like manner, so that the hydrolysis reaction is complete and there is no emulsification phenomenon. Use a phase separator to quickly separate the hydrolyzate from concentrated hydrochloric acid to avoid polymerization of the hydrolyzate under acid catalysis and improve the quality of the hydrolyzate.

Description

technical field [0001] The invention relates to the technical field of organosilicon production, in particular to the improvement and innovation of a concentrated acid hydrolysis reaction system for siloxane production. Background technique [0002] Organochlorosilanes are transformed into linear or cyclic intermediate oligomeric organosiloxanes through hydrolysis and polycondensation, which are the basis for the synthesis of silicone oil, silicone rubber, and silicone resin. In particular, dimethyldichlorosilane (hereinafter referred to as dimethyl) is recognized as the best organochlorosilane for this hydrolysis and condensation reaction. [0003] The process methods usually used for dimethyl hydrolysis include azeotropic acid hydrolysis and concentrated acid hydrolysis. No matter which hydrolysis method is used, there are problems of whether the hydrolysis is complete and how to solve the reaction heat effect. In the process of azeotropic acid hydrolysis, since the produ...

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Problems solved by technology

[0005] Chinese patent CN101323666A uses a packed tower as a hydrolysis reactor, which increases the reaction residence time, and the hydrolysis reaction is relatively complete, but it cannot be avoided that organosiloxane will polymerize on the surface of the filler or between the filler gaps

Due to the low efficiency of the stirred tank reactor, in order to achieve sufficient reaction time, the capacity must be increased, which is not conducive to the production increase of the continuous process, and the operation flexibility is small, and the liquid is easy to emulsify

[0008] Although the above-mentioned patents can directly obtain gas phase HCl, from the examples, the pressure of HCl gas is relatively low, and it is not suitable to be directly used for the synthesis of chlorinated alkanes (CN1108267A describes the importance of HCl gas pressure)

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