Patent ID: 8207377
Filing Date: 2012-06-26
Classification: C07C

Abstract:
1. A process for removing permanganate reducing compounds (PRC's) from a carbonylation product, the process comprising the steps of: (a) separating the carbonylation product produced by a carbonylation process to provide a first vapor stream comprising acetic acid and a less volatile catalyst phase; (b) distilling the first vapor stream to yield a first sidestream comprising acetic acid and a second vapor stream comprising methyl iodide, methyl acetate, and at least one PRC; (c) condensing the second vapor stream and biphasically separating the condensed second vapor stream to form a heavy liquid phase and a light liquid phase; (d) distilling a portion of the light liquid phase in a single distillation column to form a third vapor stream and a higher boiling liquid phase residuum, wherein the third vapor stream is enriched with PRC's and methyl iodide with respect to the higher boiling liquid phase residuum; and (e) condensing the third vapor stream and extracting a portion of the condensed third vapor stream with an extractant to obtain an aqueous acetaldehyde stream comprising the at least one PRC and a raffinate comprising methyl iodide.