Patent ID: 8575404
Filing Date: 2013-11-05
Classification: C07C

Abstract:
1. A process for producing ethanol comprising the steps of: hydrogenating acetic acid from an acetic acid feed stream in a reactor in the presence of a catalyst to form a crude ethanol product comprising ethanol; separating at least a portion of the crude ethanol product to yield a vapor stream and a liquid stream, wherein the vapor stream comprises unreacted hydrogen and at least one by-product gas, and wherein the liquid stream comprises ethanol and at least one dissolved by-product gas; purging less than 15% of the vapor stream in a first purge stream; purging at least a portion of at least one dissolved by-product gas from the liquid stream to form a second purge stream; returning at least a portion of the vapor stream directly or indirectly to the reactor; and recovering ethanol from the liquid stream.