Process routes for the generation of HCl gas

HCl desorption systems consist of a column that is heated by a reboiler for stripping HCl gas from acid, with azeotropic acid as a sump product. If strong hydrochloric acid is available, HCl desorption can be selected for generating HCl gas at elevated pressure (up to approx. 6 barg). The product gas composition is typically above 99,8%, while non-volatile substances remain in the azeotropic bottom product. The moisture content can be reduced to approx. 20 ppmw by chilling the HCl gas.

HCl desorption systems are operated with steam and require rather high energy input for separating HCl from water. Additionally, a weak acid is generated as a by-product, which typically needs to be handled further in a closed HCl loop.

Process routes for the generation of HCl gas