Process for the production of acetic acid from methanol and carbon monoxide using supported rhodium catalyst

Claim 1

A process for the production of acetic acid, comprising: reacting an alkyl iodide with a pyridine-containing resin to quaternize the pyridine component of said resin; reacting carbon monoxide, an alkyl iodide and a rhodium salt to form a rhodium carbonyl complex which ionically binds to the quaternized resin to form a solid catalyst; introducing a feed including methanol, carbon monoxide, an alkyl iodide and a solvent into a reaction zone containing said solid catalyst; contacting said feed with said solid catalyst to react said methanol with carbon monoxide and to obtain a reaction solution; and discharging at least a portion of said reaction solution from said reaction zone to obtain a product solution; wherein said solvent includes at least one organic solvent selected from the group consisting of carboxylic acids having at least two carbon atoms and carboxylic acid esters having at least two carbon atoms, and wherein said reaction is performed at a temperature of 140°-250° C. and a pressure of 15-60 kg/cm 2 G with a partial pressure of carbon monoxide of 7-30 kg/cm 2 while maintaining (a) the water concentration of said product solution in the range of 0.5-10% by weight and (b) the carbonylation degree C r of the solution within said reaction zone at 0.15 or more, wherein the carbonylation degree C r is given by the following equation: ##STR6## wherein M[CH 3 COOH], M[CH 3 COOCH 3 ], M[CH 3 COOR 1 ], M[CH 3 OCH 3 ], M[R 2 COOCH 3 ], M[CH 3 OR 3 ] and M[CH 3 OH] represent the amounts, in terms of molarity, of CH 3 COOH, CH 3 COOCH 3 , CH 3 COOR 1 where R 1 represents an alkyl group having at least two carbon atoms, CH 3 OCH 3 , R 2 COOCH 3 where R 2 represents an alkyl group having at least two carbon atoms, CH 3 OR 3 where R 3 represents an alkyl group having at least two carbon atoms and CH 3 OH, respectively, which are present in the solution within said reaction zone.