Separation of dewaxing solvent from dewaxed oil in a lube oil dewaxing process using asymmetric polyimide membranes
CA 1262880 C · Owner: Wight, William W. · Inventors: Wight, William W.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
Dewaxing solvents particularly ketone sol-, vents, and ketone/toluene solvents are separated from a mixture of dewaxing solvents and dewaxed oil in a lube oil dewaxing process by use of a permselective asymmetric polyimide membrane. Said asymmetric polyimide membrane permits the selective permeation of the ketone or ketone/toluene dewaxing solvent while being less permeable to oil. Said separation is conducted by contacting the ketone or ketone/toluene solvent/oil mixture with the dense side of the asymmetric polyimide membrane under pressure. The recovered ketone or ketone/toluene solvent is of high enough purity to be returned to the dewaxing process without further treatment. The …
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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
- Granted November 14, 1989. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended November 14, 2006.
- 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.