Removal of permanganate reducing compounds from methanol carbonylation process stream

摘要

An improvement of the methanol carbonylation process for manufacturing acetic acid is disclosed. Specifically disclosed is a method for reducing the formation of alkyl iodides and C_3-8 carboxylic acids by removing permanganate reducing compounds ("PRC's") from the light phase of the condensed light ends overhead stream, including (a) distilling the light phase to yield a PRC enriched overhead stream; and (b) extracting the third overhead stream with water in at least two consecutive stages and separating therefrom one or more aqueous streams containing PRC"s.