Abstract: The present invention relates to a method of reducing water from the reactor outlet gas in the oxidation process of an aromatic compound, for example, in the preparation of terephthalic acid by oxidation of xylene in an acetic acid solvent. As water is removed from the reactor outlet gas at the first absorption tower, the amount of water inflow to the dehydration tower is reduced and, thus, the amount of steam required to separate water and acetic acid at the dehydration tower is reduced and the load of the dehydration tower can be decreased. Further, by carefully controlling the flow amount of the reactor outlet gas to the first absorption tower, the operation of the dehydration tower may be made unnecessary.

Abstract: The present invention relates to a recovering method of acetic acid using an apparatus comprising a dehydration tower, a condenser and a separation tank. As p-xylene is used as an azeotropic agent to form an azeotrope with water, which is discharged from the top of the dehydration tower, and the remaining p-xylene is discharged from the bottom of the dehydration tower along with acetic acid, the acetic acid containing the p-xylene azeotropic agent can be recycled directly to a reactor for producing terephthalic acid without further separation process and without regard to the content of the p-xylene azeotropic agent which is recovered along with acetic acid.