Abstract: Processes for producing acetic acid and determining corrosion therein are described herein. The processes generally include contacting methanol and carbon monoxide in the presence of a liquid reaction medium under carbonylation conditions sufficient to form acetic acid, wherein the liquid reaction medium includes: a carbonylation catalyst selected from rhodium catalysts, iridium catalysts and palladium catalysts; from 1 wt. % to 14 wt. % water; and one or more, in-situ generated derivatives of the one or more additives and combinations thereof; wherein the one or more additives are independently selected from non-benzoyl containing pentavalent phosphine oxides, compound mixtures of at least four phosphine oxides and pentavalent aryl or alkaryl phosphine oxides including one or more benzoyl groups; and recovering acetic acid from the process.

Abstract: The present technology relates to a rhodium catalyzed carbonylation process of alcohols, ethers, and esters in the presence of phosphine oxide and ruthenium additives to produce carboxylic acids. In some embodiments, the technology provides for an improved method of preparing acetic acid from methyl acetate or methanol using a rhodium catalyst with a phosphine oxide and a ruthenium additive.