Working Principle :-
Aqueous Hydrochloric acid forms a maximum boiling point azeotrope at 110° C containing 20.24% HCL at atmospheric pressure. Thus by distilling commercial Hydrochloric acid (30%) pure HCL gas can be generated and spent acid will contain over 20.24% HCL.
Process Outline :-
Metered quantity of commercial Hydrochloric acid is preheated in a preheater by steam and fed to a fractionating column with steam as heating media in the reboiler. The vapours leaving the column are condensed with coolant as cooling water and chilled brine in stages. The relatively dry gas passes through a mist eliminator and then through a rotameter. The spent acid containing 22% HCL is cooled through a cooler and then discharged.
Salient Features :-
- Operational reliability
- Available in wide range capacities from 5 kg/hr to 200 kg/hr of dry HCL.
- Except commercial hydrochloric acid, no other raw-material is required.
- Anhydrous Gas.
- Capable of operating from 25-100%
- Ease of Installation
- Negligible pressure drop
Indicative Raw-Material & Utilities for 20kg/hr HCL :-
30% HCL - 200 Kg/hr
Saturated Steam - 50 Kg/hr
Cooling Water - 3.5 M3/hr
Chilled Brine - 4 M3/hr