Process for purging sodium sulfate from a sulfur dioxide removal system
US4200619A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 3, 1978 |
| Grant date | Apr 29, 1980 |
| Priority date | — |
| Expiry date | Jan 3, 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 containing sodium sulfate and a relatively large amount of sodium bisulfite, e.g. spent absorbing solution, is contacted with a treating gas containing at least a small amount of sulfur dioxide while reducing the amount of water in the medium so that a slurry is obtained having up to about 10, or even up to about 20, weight percent precipitated solids containing sodium sulfate in greater concentration than would otherwise be obtained in the absorption-desorption cycle. Preferably, the sulfur dioxide-containing treating gas is unsaturated with respect to water. 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 enti…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.