Abstract: A method and apparatus for sequestering entrained or volatile catalyst species in a carbonylation process includes contacting the product stream with a vinyl pyridine or a vinyl pyrrolidone resin bed which is operative to sequester entrained or volatile catalytic species. The invention is particularly useful in connection with the iridium catalyzed carbonylation of methanol wherein the loss of entrained or volatile catalyst species depletes the catalytic content of the reactor. The resin may be digested in order to recover the catalytic metals.

Abstract: An improvement to methanol carbonylation processes utilizing a homogeneous iridium catalyst system comprises adding a rate-promoting amount of an insoluble pyridine ring-containing polymer. Typically, polyvinylpyridine is added to the reactor in amounts of up to about 2 wt. percent.

Abstract: The method of the present invention provides an improvement upon prior art methanol carbonylation methods which substantially reduces the production of carbonyl impurities. The production of carbonyl impurities, particularly acetaldehyde, crotonaldehyde, and 2-ethyl crotonaldehyde, in methanol carbonylation reactions has been found to decrease by maintaining less than about 4.5 wt % methyl iodide in the reaction medium during the course of the reaction.

Abstract: The present invention provides a process for the carbonylation of an alcohol, ether or ester to products comprising a carboxylic acid, the anhydride thereof or coproduction of the carboxylic acid and anhydride. More particularly, the present invention provides a process for the carbonylation of methanol to produce acetic acid by reacting methanol with carbon monoxide in a liquid reaction medium containing a catalyst comprising rhodium, iridium, iodide ion, and said reaction medium further comprising water, acetic acid, methyl iodide, and methyl acetate and subsequently recovering acetic acid from the resulting reaction product.