PROCESS FOR RECOVERY AND REGENERATION OF DEACTIVATED CATALYSTS USED IN DIALKYL CARBONATE SYNTHESIS

• Main Authors: KELKAR, Ashutosh Anant, ROY, Lalita Sanjib, KINAGE, Anil Kisan, RANADE, Vivek Vinayak, MOTE, Dhananjay Ravindra, SHINGOTE, Savita Kiran, RANE, Vilas Hari
• Format: Patent
• Language: English; French; German
• Published: 31.01.2018
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOIDCHEMISTRY; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; THEIR RELEVANT APPARATUS; TRANSPORTING

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.