Sulfur dioxide removal process
US4216189A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 10, 1978 |
| Grant date | Aug 5, 1980 |
| Priority date | — |
| Expiry date | Oct 10, 1998 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D53/501
- 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, at least a portion of the absorbing-desorbing medium, e.g. spent absorbing solution, containing sodium sulfate and a relatively large amount of sodium bisulfite is treated to reduce the amount of water in the medium so that there is precipitated therefrom up to about 10 weight percent undissolved solids containing sodium sulfate in greater concentration than would otherwise be obtained in the absorption-desorption cycle. The insolubles containing sodium sulfate are removed from the liquid, and the liquid can be returned to the sulfur dioxide removal system. In one preferred aspect of the invention, up to about 75 weight percent of the entire stream of spent absorbing solution is treated to precipitate therefrom up to about 10 weight percent undissolved solids which are relatively rich in sodium sulfate content. In the invention th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.