Abstract: A unit for recovering hydrogen chloride from an aqueous liquid which includes hydrogen chloride and is contaminated with compounds of low or no volatility, the unit having an evaporation unit for forming, from the liquid, a vapour which contains hydrogen chloride and a liquid concentrate which is contaminated with the compounds of low or no volatility, a first distillation unit for separating the hydrogen-chloride-containing vapour into a first top product and a first bottom product, and a second distillation unit for separating a hydrogen-chloride-containing aqueous fluid into a second top product and a second bottom product, one of these two distillation units being configured to be able to implement therein a distillation above the ambient pressure, and the other of these two distillation units being configured to be able to implement therein a distillation below the ambient pressure.

Abstract: A method for producing a hydrogen chloride. A pressurized highly concentrated hydrochloric acid having a hydrogen chloride concentration of 35% by weight or above is fed into a high pressure desorption device, the high pressure desorption device is operated at a pressure Pdes of 2 bar or above and at a temperature T from 110 to 200° C. in the bottom of the high pressure desorption device, and the hydrogen chloride is desorbed in the high pressure desorption device.

Abstract: A unit for recovering hydrogen chloride from an aqueous liquid which includes hydrogen chloride and is contaminated with compounds of low or no volatility, the unit having an evaporation unit for forming, from the liquid, a vapour which contains hydrogen chloride and a liquid concentrate which is contaminated with the compounds of low or no volatility, a first distillation unit for separating the hydrogen-chloride-containing vapour into a first top product and a first bottom product, and a second distillation unit for separating a hydrogen-chloride-containing aqueous fluid into a second top product and a second bottom product, one of these two distillation units being configured to be able to implement therein a distillation above the ambient pressure, and the other of these two distillation units being configured to be able to implement therein a distillation below the ambient pressure.