Patent ID: 9676694
Date: 2017-06-13
CPC Classifications: B01D,C07C

Claim:
1. A process for producing acetic acid comprising: providing a reaction system comprising a reactor and a flash vessel; forming a reaction medium in the reactor; separating the reaction medium in the flash vessel into a liquid recycle stream and a vapor product stream; distilling at least a portion of the vapor product stream in a first column to obtain a side stream and a low boiling overhead vapor stream comprising more than 5 wt. % water; condensing and biphasically separating at least a portion of the low boiling overhead stream to form a heavy liquid phase and a light liquid phase; refluxing a portion of the heavy liquid phase, a portion of the light liquid phase, or a mixture thereof to the first column, wherein the first column is operated with a reflux ratio from 0.05 to 0.4; recycling a portion of the light liquid phase to the reaction system; maintaining a water concentration in the side stream of between 1 and 3 wt. % water and hydrogen iodide concentration in the side stream of up to 50 wppm; and distilling at least a portion of the side stream in a second column to obtain a purified acetic acid product and a second overhead comprising a water concentration from 50 to 75 wt. %.