Hydrochloric Acid Recovery and Purification
UD technologies offer Hydrochloric acid recovery plants by concentration
Aqueous Hydrochloric acid is a mixture of Hydrogen chloride and Water.
As Hydrogen chloride is highly soluble in water, Aqueous Hydrochloric acid at 25 0c, available in strength up to 30 % Hydrochloric acid.
Large Quantity of Hydrochloric acid is used in Metal Processing industry, where dilute acid is generated. So, it is necessary to install the Hydrochloric acid Recovery plant to cut costs due to neutralization and save the environment.
UD technologies offer solutions for this problem
We choose appropriate technology and Material of Construction depending on capacity.
Hydrogen chloride/water displays a maximum azeotrope at a boiling temperature of 108.6°C, for a system pressure of 1 bar and an HCl concentration of 20.2wt%.
If the acid concentration is lower than the azeotrope mixture, the acid can concentrate only up to the azeotrope point. Further, concentration needs special procedures.
The azeotrope point is suppressed as best as possible and increases the relative volatility of HCl. The relative volatility may impact by the change of the activity coefficients. So, the addition of a third ingredient achieves this effect. The third ingredient knocks out water. It displays strong hygroscopic properties. As a result; HCl gas produces at the top of the Azeotropic distillation column.
In the column, the extraction agent dilutes with water. As a result; HCl gas releases in a selective fashion from the inflowing mixture. Subsequently, the extractive agent reaches to concentration column and concentrated and returns into the Azeotrope Distillation process. Sulphuric acid and aqueous solutions of CaCl2 are appropriate extraction agents for the concentration of hydrochloric acid.
Another Method is distillation under different pressure. Azeotrope composition changes with pressure. Distillation under a vacuum produces a Higher Concentration of Hydrochloric acid from the bottom. Higher pressure produces a lower concentration of Hydrochloric acid. This effect results in better Hydrochloric acid recovery.
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