A process directed to acetic acid production comprising providing a feed stream comprising methyl iodide, water, acetic acid, methyl acetate, and at least one PRC to a distillation column comprising adistillation zone and a bottom sump zone and distilling the feed stream at a pressure and a temperature sufficient to produce an overhead stream comprising methyl iodide and at least one PRC, and a residuum stream flowing from the bottom sump zone comprising water and greater than or equal to about 0.11 weight percent HI is disclosed herein.