Use of pentavalent Group VA oxides in acetic acid processing

Claim 1

A process for the production of acetic acid without the use of an alkali metal halide comprising contacting methanol or methyl acetate with carbon monoxide in the presence of a carbonylation system containing from about 200 to about 1200 ppm of a rhodium-containing component and a liquid reaction medium comprising from about 20 to about 80 weight % acetic acid; from about 0.6 to about 36 weight % methyl iodide; from about 0.5 to about 10 weight % methyl acetate, said contacting being in the presence of at least one pentavalent Group VA oxide of the formula R 3 M═O, wherein M is an element of Group VA of the Periodic Table of the Elements; and each R is independently a substituted or an unsubstituted alkyl containing up to 12 carbon atoms, an aryl containing from 6 to 14 carbon atoms, an aralkyl containing up to 16 carbon atoms wherein each aryl group contains from 6 to 10 carbon atoms and each alkyl group contains up to 6 carbon atoms or an alkaryl containing up to 16 carbon atoms wherein each alkyl group contains up to 8 carbon atoms and each aryl group contains from 6 to 10 carbon atoms, wherein any of said substituents of the carbon chains may be straight, branched or both, wherein said pentavalent Group VA oxide is present in a concentration of said Group VA oxide to rhodium of greater than about 60:1, and water, said water being added in an amount of from about 4 to about 12 weight %, based on the total weight of said carbonylation system.