Preparation method of electronic-grade high-purity hydrogen chloride

Abstract

The invention discloses a preparation method of electronic-grade high-purity hydrogen chloride. The preparation method includes subjecting toluene and chlorine to a chlorination reaction to produce chlorotoluene and a by-product, namely a hydrogen chloride gas, dewatering, liquefying and rectifying the by-product as a raw material to remove light components, and further performing rectification to remove heavy components to obtain the electronic-grade high-purity hydrogen chloride. The preparation method has the advantages that an original process for converting hydrogen chloride produced after toluene chlorination into hydrochloric acid is changed into a method for producing the electronic-grade high-purity hydrogen chloride, and the industrial hydrochloric acid is basically surplus waste liquid in actual chemical production and needs to be treated; by the preparation method, waste is turned into treasures, and new pollution is avoided.

Description

technical field [0001] The invention relates to the field of purification, in particular to a method for preparing electronic-grade high-purity hydrogen chloride. Background technique [0002] The prior art production of hydrogen chloride mainly adopts the following methods: [0003] Method 1: synthetic method; [0004] 3.1.1. Basic principle: Combustion of hydrogen and chlorine to generate hydrogen chloride H 2 +CL 2 →2HCL [0005] 3.1.2. Disadvantages and drawbacks: [0006] (1) It is more difficult to ignite; [0007] (2) Once the flameout occurs during the combustion process, it will be troublesome to re-ignite, there is a risk of explosion, and the safety hazard is relatively large; [0008] (3) The combustion process brings huge heat energy and is cooled by water. Once the reactor is broken down, a huge acidic liquid hydrochloric acid is formed, which is difficult to handle, and it is a precursor drug. Poor management and potential social harm are huge; [0009]...

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Problems solved by technology

[0006] (1) It is more difficult to ignite;

[0007] (2) Once the flameout occurs during the combustion process, it will be troublesome to re-ignite, there is a risk of explosion, and the safety hazard is relatively large;

[0008] (3) The combustion process brings huge heat energy and is cooled by water. Once the reactor is broken down, a huge acidic liquid hydrochloric acid is formed, which is difficult to handle, and it is a precursor drug. Poor management and potential social harm are huge;

[0012] (1) Concentrated hydrochloric acid and hot concentrated sulfuric acid have serious corrosiveness, have harsh requirements on equipment, and the equipment manufacturing cost is high;

[0013] (2) A large amount of waste acid (a mixture of hydrochloric acid and sulfuric acid) is produced in the production process, and the pressure on environmental protection is huge;

[0014] (3) A large amount of heat is generated during the production process, which is likely to cause violent boiling of the mixed acid and splashing of high-temperature liquid, and the safety is not high;

[0015] (4) Concentrated hydrochloric acid and concentrated sulfuric acid are precursors to drug control substances, and the administrative procedures for procurement and transportation are troublesome;

[0020] (1) The hydrochloride of alkali metals is easy to harden and agglomerate during the roasting process, resulting in incomplete completion of the reaction, serious consumption of materials, more solid waste generated, and huge pressure on environmental protection;

[0021] (2) There are other weak salt substances in the hydrochloride of alkali metals, and there are other acidic substances in the double decomposition reaction process, such as: hydrogen sulfide, hydrogen bromide, carbon dioxide, etc., there are many impurities, and the subsequent purification treatment is difficult, and the product Poor quality stability;

[0022] (3) The metathesis reaction temperature is high, the material requirements for the reactor are strict, the energy consumption is high, and the economic value advantage is not obvious

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