Acetic acid product quality improvement

Abstract

A process of purifying acetic acid is provided. The process includes feeding a feed stream comprising acetic acid into a bottom half of a distillation column and distilling the acetic acid in the presence of a homogeneous oxidizing agent in the distillation column, to oxidize oxidizable impurities in the acetic acid, wherein the homogeneous oxidizing agent is capable of cleaving C═C bonds. The process further includes removing a distilled acetic acid stream from the distillation column. Further processes for purifying acetic acid and systems for purifying acetic acid are also provided.

What is claimed is: 
     
         1 . A process for purifying acetic acid, comprising:
 feeding a feed stream comprising acetic acid into a bottom half of a distillation column;   distilling the acetic acid in the presence of a homogeneous oxidizing agent in the distillation column to oxidize oxidizable impurities in the acetic acid, wherein the homogeneous oxidizing agent is capable of cleaving C═C bonds; and   removing a distilled acetic acid stream from the distillation column,   wherein the homogeneous oxidizing agent is positioned in the feed stream.   
     
     
         2 . The process of  claim 1 , wherein the oxidizable impurities comprise an α,β-unsaturated carbonyl compound. 
     
     
         3 . The process of  claim 2 , wherein the α,β-unsaturated carbonyl compound comprises an α,β-unsaturated carboxylic acid. 
     
     
         4 . The process of  claim 3 , wherein the α,β-unsaturated carboxylic acid comprises acrylic acid. 
     
     
         5 . The process of  claim 1 , wherein the distillation column comprises a sump in the bottom half of the distillation column and the homogeneous oxidizing agent is positioned in the sump. 
     
     
         6 . A process for purifying acetic acid, comprising:
 feeding a feed stream comprising acetic acid into a distillation column, and   distilling the acetic acid in the presence of a homogeneous oxidizing agent,   wherein:
 the distillation column comprises:
 a top half and a bottom half; and 
 a sump in the bottom half of the distillation column; and 
 
   wherein the feed stream is fed into the bottom half of the distillation column; and   wherein the homogeneous oxidizing agent is positioned in the feed stream.   
     
     
         7 . The process of  claim 1 , wherein the homogeneous oxidizing agent comprises potassium permanganate. 
     
     
         8 . The process of  claim 7 , wherein the potassium permanganate comprises an aqueous solution of potassium permanganate. 
     
     
         9 . The process of  claim 7 , wherein the potassium permanganate comprises potassium permanganate on a solid support. 
     
     
         10 . The process of  claim 9 , wherein the solid support is silica. 
     
     
         11 . The process of  claim 1 , wherein the process further comprises feeding the distilled acetic acid stream through a sorbent phase capable of removing at least one impurity selected from water, or formic acid, or aldehydes. 
     
     
         12 . The process of  claim 1 , wherein the process further comprises additional distillation of acetic acid through an additional distillation column. 
     
     
         13 . The process of  claim 6 , wherein the homogeneous oxidizing agent comprises potassium permanganate. 
     
     
         14 . The process of  claim 13 , wherein the potassium permanganate comprises an aqueous solution of potassium permanganate. 
     
     
         15 . The process of  claim 13 , wherein the potassium permanganate comprises potassium permanganate on a solid support.