Preparation method of hydrochloric acid

hydrochloric acid

[Physical and chemical properties] Hydrochloric acid, also known as hydrochloric acid, salt water, solder potion, molecular formula HCI, relative molecular mass 36.

[Preparation]

(1) Electrolysis method

The Cl ₂ and H ₂ obtained by the diaphragm electrolysis of table salt are synthesized through synthesis

(2) Chemical method

The HCl obtained by the reaction of table salt and H ₂ SO ₄ is obtained by absorbing water

(3) Chinese Patent CN1113878A

This method is to absorb 50%-100% of the hydrochloric acid gas synthesized by Cl ₂ and H ₂ in the existing hydrochloric acid production, and then mix it with Cl ₂ or H ₂ before returning to the hydrochloric acid synthesis furnace after heating and pressurizing or spraying suction ; or Before returning to the hydrochloric acid absorption tower, it is mixed with HCI gas and then recycled, basically achieving zero emission of tail gas

(4) Chinese Patent CN101139724A

This process uses solar panels to generate electricity from sunlight, and uses high temperature to concentrate the salt of seawater to increase the concentration, and then electrolyze the high-concentration brine to generate sodium hydroxide, hydrogen and chlorine, and then gasify hydrogen and chlorine to synthesize hydrogen chloride In this way, hydrochloric acid and caustic soda can be obtained at the same time

(5) Preparation method of European patent 0618170A1 reagent grade hydrochloric acid

The inventor uses the hydrogen chloride produced by isocyanate to prepare reagent-grade hydrochloric acid, collects the hydrogen chloride in the isocyanate reactor, concentrates it, and converts it into a hydrochloric acid solution, and finally removes iron with a strong basic anion exchange resin

(6) Chinese patent CN101200285A

The technical scheme is to react a concentrated solution of calcium chloride or sodium chloride with concentrated sulfuric acid under heating conditions to generate corresponding sulfates, release hydrogen chloride, and use the released hydrogen chloride to produce polyvinyl chloride and hydrochloric acid

①Using NaCl as raw material

The salt (NaCl) is prepared into a solution of about 25% and heated to about 90°C

②Using soda ash waste liquid as raw material

The soda ash waste liquid is clarified to obtain a clear liquid (containing 10% CaCl ₂ and 4% to 5% NaCl), and the clear liquid is evaporated by an evaporator.

Put the muddy white precipitate calcium sulfate produced by the reaction into the suction filter box to separate calcium sulfate (gypsum)

The HCI is drawn from the top of the reactor, the entrained moisture and sulfuric acid are condensed through the condenser, and then sent back to the evaporator

In the production of soda ash, an average of 10m3 of waste liquid is discharged for every 1t of soda ash produced, and the clarified waste liquid contains 10% CaCl ₂ and 4% to 5% NaCl

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