Patent ID: 8575402
Filing Date: 2013-11-05
Classification: C07C,Y02P

Abstract:
1. A process for the production of an alkylene glycol from an alkene comprising the steps of: i) converting the alkene in the presence of oxygen and an epoxidation catalyst to the corresponding alkylene oxide in an epoxidation reactor; ii) absorbing the alkylene oxide in an aqueous absorbent and then stripping said absorbent to provide an aqueous alkylene oxide stream; iii) supplying the aqueous alkyene oxide stream at an inlet to a carboxylation reactor; iv) converting the aqueous alkylene oxide stream in the presence of one or more carboxylation-hydrolysis catalysts and carbon dioxide to a stream comprising the corresponding alkylene carbonate in one or more carboxylation reactors; v) converting the stream comprising the alkylene carbonate to a stream comprising the alkylene glycol in one or more hydrolysis reactors; vi) removing water from the stream comprising the alkylene glycol to form a dehydrated alkylene glycol stream in one or more dehydration columns; vii) purifying the dehydrated alkylene glycol stream in one or more glycol distillation columns to form a purified alkylene glycol product stream and a carboxylation-hydrolysis catalyst recycle stream, wherein the start-up procedure for said process comprises supplying water, carboxylation-hydrolysis catalyst and carbon dioxide streams to the carboxylation reactor and providing a start-up stream comprising the alkylene glycol at an injection point at or downstream of the inlet used in step iii) and recovering an alkylene glycol stream from the glycol distillation column.