Sulphur dioxide removal process
US4207299A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 30, 1978 |
| Grant date | Jun 10, 1980 |
| Priority date | — |
| Expiry date | Aug 30, 1998 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B17/00
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Sodium sulfate 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. The spent absorbing solution is regenerated by desorbing sulfur dioxide, and recycled for further use. To avoid an unduly large build-up of sulfate in the system, a portion of the absorbing-desorbing medium, e.g., spent absorbing solution, containing sodium sulfate, a relatively large amount of sodium bisulfite, and generally a minor amount of sodium sulfite, is treated to precipitate solids containing sodium sulfate in a concentration which is greater on a dry basis than would otherwise be obtained in the absorption-desorption cycle. The concentration of sodium sulfate in the precipitated solids is increased by providing a portion of the precipitated sodium sulfate-containing solids, e.g. about 25 to 75 weight percent, in solution in the absorbing-desorbing medium treated for sulfate removal. Preferably, sulfate removal is accomplished by reducing the amount of water in the portion of the absorbing-desorbing medium treated so that only sufficient solids are precipitated from said medium t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.