Patent ID: 8686201

Claim:
A process for producing ethanol, comprising the steps of: reacting carbon monoxide with at least one reactant in a reactor containing a reaction medium to produce a reaction product comprising acetic acid, wherein the reaction medium comprises water, acetic acid, methyl acetate, a halogen promoter, and a first catalyst; separating the reaction product in a flasher into a liquid recycle stream and a vapor stream comprising acetic acid, the halogen promoter, methyl acetate and water; distilling the vapor stream in a rectification tower and withdrawing an overhead stream comprising more than 90% of the water from the reaction product and an acetic acid feed stream at a point below where the vapor stream is introduced to the tower; condensing the overhead stream and biphasically separating the overhead stream into an aqueous stream and an organic stream; refluxing a portion of the aqueous stream to the rectification tower; directing a portion of the aqueous stream to the flasher as a washing liquid to remove the first catalyst from a vapor phase; hydrogenating acetic acid of the acetic acid feed stream in the presence of a second catalyst and under conditions effective to form a crude ethanol product; and recovering ethanol from the crude ethanol product.