Patent ID: 9382186
Filing Date: 2016-07-05
CPC Classification: C07C

Claim Text:
1. A process for producing acetic acid comprising: separating a reaction medium formed in a reactor in a flash vessel to form a liquid recycle and a vapor product stream, wherein the reaction medium comprises water in an amount from 0.1 to 4.1 wt. %; distilling a portion of the vapor product stream in a first column to obtain a side stream, a low boiling overhead vapor stream comprising water in an amount of greater than or equal to 5 wt. %, and a residuum stream comprising acetic acid in an amount greater than or equal to 95 wt. % and water in an amount less than or equal to 5 wt. %; condensing the low boiling overhead vapor stream and biphasically separating the condensed stream to form a heavy liquid phase and a light liquid phase; maintaining a water concentration in the side stream from 1 to 3 wt. % and a hydrogen iodide concentration in the side stream of less than or equal to 50 wppm, based on the total weight of the side stream, by controlling a recycle rate of a portion of the light liquid phase to the reactor; and distilling the side stream in a second column to obtain a purified acetic acid product.