Process for removing sulfur dioxide and nitrogen oxides from flue gases
CA 2072161 C · Owner: Lee, Yungli J. · Inventors: Lee, Yungli J.; Benson, Lewis B.; College, John W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
A process for removing sulfur dioxide and nitrogen oxide from flue gases in a wet scrubbing system using lime to remove the sulfur dioxide and ferrous-EDTA to remove the nitrogen oxides, where an initial reducing agent such as, sodium sulfide, and an antioxidant such as hydrazine, are, added to the scrubbing system with oxidation of the ferrous-EDTA, to ferric-EDTA curtailed while removal of nitrogen oxides is increased.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed June 23, 1992 and granted March 16, 1999. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended June 23, 2012.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by June 23, 2014.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.