Reducing ethyl acetate concentration in recycle streams for ethanol production processes

摘要

Recycle streams in an ethanol production process are hydrolyzed to reduce ethyl acetate concentration. In the process, acetic acid is hydrogenated to form a crude ethanol product, which undergoes a separation or purification process. Ethyl acetate is formed as a byproduct of the hydrogenation of acetic acid. The hydrolysis of recycle steams from the separation process can reduce the concentration of ethyl acetate, converting some or all of the ethyl acetate to acetic acid and ethanol.

主权项

1. A process for producing ethanol, comprising:
hydrogenating an acetic acid and ethyl acetate stream in a reactor in the presence of a catalyst to form a crude ethanol product; separating at least a portion of the crude ethanol product in a first distillation column to yield a first residue comprising acetic acid and a first distillate comprising ethanol, ethyl acetate, and water; removing water from at least a portion of the first distillate to yield an ethanol mixture stream comprising less than 10 wt.% water; separating a portion of the ethanol mixture stream in a second distillation column to yield a second residue comprising ethanol and a second distillate comprising ethyl acetate; and hydrolyzing at least a portion of the second distillate to form a hydrolyzed stream.