Process for producing acetic acid

摘要

A process for producing acetic acid is disclosed in which the water concentration is controlled in the side stream between two columns. Controlling the water concentration by a recycle rate of the light liquid phase maintains the hydrogen iodide concentration in the side stream to be up to 50 wppm.

主权项

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; controlling a recycle rate of the light liquid phase to the reaction system to maintain a water concentration in the side stream from 1 to 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.