Process for absorption of sulfur compounds from fluids using certain piperidines, piperazines, or anhydrides of monocarboxylic amino acids
CA 2049151 C · Owner: Crump, Druce K. · Inventors: Chang, Dane; Crump, Druce K.; Christiansen, Steven H.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Sulfur dioxide is removed from a fluid containing SO2 by employing as an absorbent for the SO2 an aqueous solution of a compound represented by Formulas I II or III. Where Formula I is:, (see formula I) wherein each Y is independently -(CR22)- or -(CR2)= and each R1 or R2 is independently hydrogen, an alkyl group; an hydroxyalkyl group; an aldehyde group; a carboxylic acid group or salt thereof; an alkyl group containing at least one carboxylic ester, a carboxylic acid or salt thereof ether, aldehyde, ketone, or sulfoxide group; wherein the compound has at least one carbonyl group. Formula II is: wherein each R3 is independently hydrogen; an alkyl group; a hydroxyalkyl group; an aldehyde …
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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 August 15, 1991 and granted August 14, 2001. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended August 15, 2011.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by August 15, 2013.
- 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.