HCl Gas Generation Plants

Additional Details

The plant has been designed as a continuous process to produce dry HCl gas by the process of distillation of 30% hydrochloric acid solution along with a co-current stream of calcium chloride solution. A pre-heated stream of 30% hydrochloric acid solution is fed to the azeotropic distillation column (C-1). Simultaneously a co-current feed of concentrated calcium chloride is also fed to the distillation column. The calcium chloride breaks the azeotrope formed between HCl and water and as a result almost all the HCl available in the soln. is released as gas. The heat exchangers (E-2 and E-4) are designed as thermosyphon reboilers where the heat energy for the distillation process and the evaporation process is supplied by steam. The vapour from the reboiler strips the available gas from the feed acid soln. in the column. The top product HCl gas is dried in the Drying Unit using a suitable dehydrating agent. The moisture content in the product HCl gas is expected to be less than 0.001%. The bottom product from the column (C-1) is dilute calcium chloride solution with some HCl content.