Processes and Apparatuses for Distillation of an Acetic Acid and Propionic Acid-Containing Stream in an Acetic Acid Production Unit

A process for separating a feed stream comprising acetic acid and propionic acid in a distillation column, the distillation column comprising

• a bottom section in thermal communication with a heat source;
• a feed inlet positioned at a level above the bottom section;
• a first draw outlet positioned at a level above the feed inlet;
• a second draw outlet positioned at a level between the feed inlet and the first draw outlet;
• a vapour outlet positioned at a level above the first draw outlet;
• and
• a bottoms outlet positioned at a level within the bottom section;
• the process comprising
• providing heat from the heat source at the bottom section of the distillation column;
• introducing the feed stream into the distillation column through the feed inlet;
• withdrawing a first product stream comprising acetic acid and propionic acid from the first draw outlet;
• and
• withdrawing a second product stream comprising acetic acid and propionic acid from the second draw outlet;
• wherein
• a volume ratio of the first product stream to the second product stream is in the range of 1:9 to 19:1;
• and
• an amount of propionic acid present in the second product stream is at least 50 ppmw greater than the amount of propionic acid present in the first product stream.