Recovering ethanol with sidestreams to regulate C₃+ alcohols concentrations

摘要

This invention relates to purification and/or recovery of ethanol from a crude ethanol product obtained from the hydrogenation of acetic acid. Separation and purification processes of a crude ethanol mixture are employed to allow recovery of ethanol and remove impurities. In particular, the process involves one or more sidestreams to regulate C3+ alcohols concentration in the recovered ethanol.

主权项

1. A process for producing ethanol, comprising:
hydrogenating acetic acid in a reactor in the presence of a catalyst to form a crude ethanol product; separating a portion of the crude ethanol product in a first distillation column to yield a first distillate comprising ethyl acetate and a first residue comprising one or more C2+ alcohols, acetic acid and water, wherein a majority of ethanol in the crude ethanol product that is fed to the column is removed in the first residue; and separating a portion of the first residue in a second distillation column to yield a second residue comprising acetic acid and water, a second distillate comprising ethanol, and one or more sidestreams comprising one or more C3+ alcohols.