Sulfur dioxide removal process
US4122148A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 1976 |
| Grant date | Oct 24, 1978 |
| Priority date | — |
| Expiry date | Apr 20, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B17/60
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Sodium thiosulfate is purged from a sulfur dioxide removal system involving contact of a sulfur dioxide-containing gas with a solution containing sodium sulfite to absorb sulfur dioxide from the gas. A portion of the liquid from a desorption zone containing a minor amount of sodium thiosulfate and a relatively large amount of sodium bisulfite, is treated to reduce the amount of water in the medium so that solids are precipitated from the liquid phase. The insolubles containing sodium sulfites are removed from the liquid. The liquid separated from the solids can be discarded and thereby purge thiosulfate more selectively with respect to other sodium salts. Also, the sodium values of the sodium thiosulfate-containing purge liquid can be recovered in active form by chemical reduction, and, preferably, carbonation. A sodium sulfate purge material from the absorption-desorption system can also be subjected to the chemical reduction system for further recovery of active sodium values.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.