Hydrochloric Acid Concentration and Purification
Aqueous Hydrochloric acid is a mixture of Hydrochloride and Water. As Hydrochloride is highly soluble in water, Aq, 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. It is necessary to recycle Hydrochloric acid to cut costs due to neutralization and environment.
UD technologies offer solutions for this problem and offer Hydrochloric acid Concentration plants. 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 be concentrated only up to the azeotrope point. Further concentration needs special procedures.
We have considered the most economical contemporary technology “Azeotropic distillation & Absorption Technology”. This is an economical technology. The azeotrope point is suppressed as best as possible and increases the relative volatility of HCl. The relative volatility may be impacted by the change of the activity coefficients. This is achieved by the addition of a third ingredient, which knocks out water and displays strong hygroscopic properties. Conc. HCL & HCl gas is produced at the head of the Azeotropic distillation and Absorption column depending upon the choice of an appropriate extraction agent. In the column, the extraction agent is diluted with water, which is extracted in a selective fashion from the inflowing mixture. Subsequently, the extractive agent is recycled and concentrated and fed into the Azeotrope Distillation process. Sulphuric acid and aqueous solutions of CaCl2 are appropriate extraction agents for the concentration of hydrochloric acid.