The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 07, 2021
Filed:
Mar. 23, 2016
Council of Scientific and Industrial Research, New Delhi, IN;
Vivek Vinayak Ranade, Pune, IN;
Ashutosh Anant Kelkar, Pune, IN;
Vilas Hari Rane, Pune, IN;
Anil Kisan Kinage, Pune, IN;
Savita Kiran Shingote, Pune, IN;
Lalita Sanjib Roy, Pune, IN;
Dhananjay Ravindra Mote, Pune, IN;
COUNCIL OF SCIENTIFIC & INDUSTRIAL RESEARCH, New Delhi, IN;
Abstract
The present invention discloses a process for recovery and regeneration of rare earth metals or salts thereof used as catalyst and which is conveniently integrated within the overall flow sheets of manufacturing dialkyl carbonates. Alkyl carbamate, alcohol and a rare earth metal salt as catalyst selected from the lanthanide series are added in a reactor to afford dialkyl carbonate. The rare earth metal catalyst is selected from samarium, cerium, lanthanum, neodymium, ytterbium, europium and gadolinium. Ammonia is added to a portion of the reaction mixture to precipitate the catalyst and the separated deactivated catalyst is dissolved in acid to afford regenerated catalyst, e.g., in triflic acid in the case of samarium triflate catalyst.