Patent ID: 7115774

Claim:
A process for carbonylating alcohols with carbon monoxide in the liquid phase, said process comprising: carrying out the carbonylation reaction in a reaction zone at a temperature of 50° C. to 150° C. and at a pressure in the range 0.5 MPa to 20 MPa in the presence of at least one catalyst comprising at least one rhodium and/or iridium complex and a halogenated promoter in at least one non-aqueous ionic liquid comprising at least one salt of the formula Q + A − , in which Q + represents a quaternary ammonium and/or a quaternary phosphonium cation, and A is an anion capable of forming a liquid salt below 90° C., said salt having a melting point of less than 90° C., withdrawing an effluent from the reaction zone and separating from the effluent the non-aqueous ionic liquid containing in dissolved form substantially all rhodium and/or iridium values in the effluent; and recycling at least partly the resultant separated non-aqueous ionic liquid to the reaction zone.