Method for obtaining gaseous hydrogen chloride from dilute aqueous hydrochloric acid
US4259309A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1979 |
| Grant date | Mar 31, 1981 |
| Priority date | — |
| Expiry date | Aug 8, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B7/01
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An improvement in the process for obtaining gaseous hydrogen chloride by extracting dilute aqueous hydrochloric acid with amines wherein: PA1 (a) the aqueous hydrochloric acid is extracted with an amine or a mixture of an amine and an inert, water-immiscible solvent boiling at not less than 120.degree. C., using tertiary alkylamines which contain 14 to 36 carbon atoms in the nitrogen-bonded side chains, which side chains include at most one nitrogen-bonded methyl group and at least one nitrogen-bonded aliphatic radical containing at least 6 carbon atoms, the acid constant K.sub.a of the amine being less than 10.sup.-3 ; PA1 (b) an inert, water-immiscible solvent boiling at not less than 120.degree. C. is added to the extract, unless the solvent has already been added in stage (a); PA1 (c) the extract is distilled, the resulting vapors are condensed, the water is continuously removed from the two-phase condensate, and the organic phase is returned to the distillation process; PA1 (d) the extract is distilled, under reflux, after the water has been removed, and the gaseous hydrogen chloride liberated at the top of the column is taken off, or the hydrogen chloride is separated off at …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.