Removal of by-products in method for processing a gas containing hydrogen sulfide and sulfur dioxide
US6280698A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1999 |
| Grant date | Aug 28, 2001 |
| Priority date | — |
| Expiry date | Nov 22, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B17/05
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method for processing a gas, such as a Claus tail gas, containing at least hydrogen sulfide (H.sub.2 S) and at least sulfur dioxide (SO.sub.2), includes the steps of contacting the gas with a liquid solvent, such as polyethylene glycol, containing at least one catalyst, such as sodium salicylate, in a contacting stage, recovering gaseous effluent substantially containing no hydrogen sulfide and no sulfur dioxide from the contacting stage, and separating liquid sulfur from liquid solvent in a decantation zone beneath the contacting stage. In order to remove by-products, such as sulfate and thiosulfate salts, resulting from degradation of the catalyst, a liquid fraction F containing at least solvent, catalyst, sulfur and the solid by-products resulting from degradation of the catalyst is extracted from the contacting stage and sent to a processing stage distinct from the contacting stage where the liquid fraction F is heated to a temperature sufficient to at least partially crystallize the by-products, and the crystallized by-products are separated from the rest of the liquid fraction F containing at least solvent. At least a stream F.sub.1 comprising solvent, catalyst and sulfur a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.