A kind of concentrated hydrochloric acid hydrolysis process and device

Abstract

The invention provides a concentrated-acid hydrolysis technology. The concentrated-acid hydrolysis technology includes the steps that after hydrolysis raw materials of dimethyldichlorosilane and saturated concentrated hydrochloric acid are reacted in a static mixer, the obtained gas-liquid mixture enters a gas-liquid separation tank A, gas recovered out of the top of the gas-liquid separation tank A, carried dimethyldichlorosilane and carried hydrolysate liquid drops enter a venturi mixer from the side face, the gas-liquid mixture deeply mixed in a main concentrated-hydrochloric-acid fluid enters a gas-liquid separation tank B, concentrated hydrochloric acid recovered out of the bottom of the gas-liquid separation tank B is returned to the venturi mixer through a material pump, the gas recovered out of the top sequentially enters a primary condenser and a secondary condenser, gas-liquid mixture condensed by the primary condenser and the secondary condenser enters a collecting device to collect liquid drops, and after the liquid drops are removed through a demister, the product is delivered to a chloromethane synthesis working section through a buffering tank. By means of the concentrated-acid hydrolysis technology, in the concentrated-acid hydrolysis process, the insufficient reacting problem, the low efficiency problem and the like caused when materials are unevenly mixed are solved, and meanwhile the problems that as gas and liquid are carried, a pipe and a device are blocked are solved.

Description

technical field [0001] The invention relates to a high-efficiency concentrated acid hydrolysis process, which belongs to the technical field of organosilicon hydrolyzate production. Background technique [0002] The hydrolysis of dimethyldichlorosilane can use azeotropic acid with a mass fraction of 21%-22% as a raw material. After the hydrolysis reaction, the mixture is separated by a water separator. The upper layer is the product hydrolyzate, which enters the cracking section after being boiled and neutralized. The lower layer is the by-product concentrated hydrochloric acid, which enters the hydrogen chloride desorption tower to decompose hydrogen chloride gas for the synthesis of methyl chloride. The disadvantage of azeotropic acid hydrolysis is that the hydrogen chloride molecules generated by the hydrolysis reaction have a high heat of solution in dilute acid. In order to prevent the hydrolysis temperature from being too high, a large amount of cooling capacity is req...

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Problems solved by technology

The disadvantage of azeotropic acid hydrolysis is that the hydrogen chloride molecules generated by the hydrolysis reaction have a high heat of solution in dilute acid. In order to prevent the hydrolysis temperature from being too high, a large amount of cooling capacity is required for cooling; The reboiler needs to consume a lot of heat; the hydrolyzate entrained in the concentrated acid will also self-accumulate and settle in the desorption column, forming a jelly, which affects the normal operation of the equipment

However, the concentrated acid hydrolysis process still has the following deficiencies: (1) In the current technological process, static mixers are mainly used as hydrolysis reactors, but the materials in the static mixers cannot be deeply mixed on the molecular scale, resulting in the localization of the materials in the reaction system. Excessive, resulting in a decrease in the yield of cyclic bodies in the hydrolyzate, resulting in more short-chain linear bodies with hydrophilic hydroxyl groups at the chain ends. The linear bodies have a certain degree of hydrophilicity and hydrophobicity at the same time, so it is easy to emulsify in the water separator and not It is beneficial to the separation of oil and water, and is easily carried by hydrogen chloride gas, and is easy to self-polymerize, forming a jelly in the methyl chloride synthesis section; (2) under the existing process conditions, the hydrogen chloride gas produced from the top of the gas-liquid separation tank is condensed The diameter of the post-condensate droplet is still smaller than the effective treatment diameter of the demister (3-5 μm), and the demister cannot completely remove the hydrolyzate carried in the hydrogen chloride gas

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