Removal of contaminants from gas streams in rayon production
CA 2289845 A1 · Owner: Mueller, Christopher R. · Inventors: Mueller, Christopher R.; Spink, Edward F.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Sulfurous gas streams comprising hydrogen sulfide and carbon disulfide such , as produced as a by-product of the rayon-forming process are processed to , recover the components in a useable form. The gas stream first is contacted with an aqueous sodium hydroxide to dissolve out hydrogen sulfide and some of the carbon disulfide. The dissolved carbon disulfide is driven off from the solution and condensed as a liquid concentrate. Carbon disulfide receiving in the gas stream is recovered, such as by condensation. The aqueous sodium sulfide solution which remains is concentrated and the pH is adjusted as , necessary, to a value at which the sodium sulfide is predominantly in the form of …
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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 May 21, 1998. No grant is recorded for it in Canada; had it been granted, its 20-year term would have ended May 21, 2018.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 21, 2020.
- 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
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Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.