Process for absorption of sulfur dioxide and nitric oxide from flue gas
US5320816A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1992 |
| Grant date | Jun 14, 1994 |
| Priority date | — |
| Expiry date | Oct 21, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB01D61/44
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The simultaneous abatement of NO and SO.sub.2 in flue gas is provided by an absorption process and apparatus utilizing an absorbent composition comprising an aqueous solution of chelates and sulfite salts. Metal chelates oxidized to an inactive state are electrochemically reduced. In the electrochemical cell, nickel or stainless steel anode materials are stable and may be used in the place of platinum coated anode materials when the anolyte pH is maintained greater than 12. At these conditions, the anode is corrosion resistant with a long operating time between replacement. Ultrafiltration or Donnan dialysis may be used to separate the chelate sorbents from the waste salts to reduce the loss of expensive chelate sorbents. Alternatively, an anionic exchange membrane can be used to electrodialytically separate waste sulfur/nitrogen salts from the absorbent solution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.