Integrated process using in situ regenerated sulfuric acid as catalyst
CA 2194902 C · Owner: Chou, Chao-Shan · Inventors: Chen, Yi-Lin; Chou, Chao-Shan; Chou, Tse-Chuan
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
This invention discloses an integrated process of alkylation of olefins and regeneration of spent sulfuric acid. The alkylation of olefins may be replaced by nitration of toluene or by chlor-alkali process. The sulfuric acid is used as a catalyst or a absorbent, and the spent sulfuric acid is regenerated in situ and is recycled in the alkylation of olefins, nitration of toluene or chlor-alkali processes.
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 January 10, 1997 and granted September 17, 2002. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended January 10, 2017.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by January 10, 2019.
- 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.