Selective removal of H.sub.2 S from steam also containing CO.sub.2
US4500500A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1983 |
| Grant date | Feb 19, 1985 |
| Priority date | — |
| Expiry date | Jul 22, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D53/1493
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Essentially all of the H.sub.2 S in steam which also contains up to 30 ppmw of CO.sub.2 per ppmw of H.sub.2 S can be scrubbed from the steam with aqueous NaOH or Na.sub.2 CO.sub.3 without consuming more than about 4 mols of NaOH or 2 mols of Na.sub.2 CO.sub.3 per mol of H.sub.2 S and without consuming more than about 0.18 pounds of water per pound of steam scrubbed, if (1) the steam is scrubbed countercurrently in a tower containing a contacting means equivalent to at least 6 theoretical stages, (2) the sulfide species in the tower effluent are completely oxidized to sulfo species and (3) the oxidized effluent--less a bleed stream and plus water and base makeup--is recycled to the tower. If the steam is scrubbed in this manner before being introduced to the turbines in a power plant, the exhaust from the turbines can be vented to the atmosphere without further treatment. The method of the invention is particularly suited for use at the Geysers geothermal "steam" field in California.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.