Patent ID: 9334222
Filing Date: 2016-05-10
CPC Classification: B01D,C07B,C07C,Y02P

Claim Text:
1. A method of separating off water and recovering acetic acid from a discharge discharged from a reactor during oxidation of a phthalic acid compound, the method comprising: flowing the discharge into a first dehydration tower that is in a decompressed or atmospheric state after the discharge passes through each device for processes so as to discharge water to a top part of the first dehydration tower, and recovering a first concentrated acetic acid from a lower part of the first dehydration tower; and flowing the first concentrated acetic acid discharged from the lower part of the first dehydration tower into a center of a second dehydration tower that is in an atmospheric or pressurized state so as to recover a final concentrated acetic acid from a lower part of the second dehydration tower, wherein working pressures of the first dehydration tower and the second dehydration tower are respectively from −0.8 to −0.5 kg/cm